Fulthorpe, C.S., Hoyanagi, K., Blum, P., and the Expedition 317 Scientists
Proceedings of the Integrated Ocean Drilling Program, Volume 317
Site U13541
Expedition 317 Scientists2
Chapter contents
Background and objectives . . . . . . . . . . . . . . . . 1
Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Lithostratigraphy. . . . . . . . . . . . . . . . . . . . . . . . 3
Biostratigraphy . . . . . . . . . . . . . . . . . . . . . . . . . 8
Paleomagnetism . . . . . . . . . . . . . . . . . . . . . . . 11
Physical properties . . . . . . . . . . . . . . . . . . . . . 12
Geochemistry and microbiology. . . . . . . . . . . 14
Heat flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Downhole logging . . . . . . . . . . . . . . . . . . . . . 18
Stratigraphic correlation . . . . . . . . . . . . . . . . . 20
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Background and objectives
Hole U1354A
Position: 44°50.8281′S, 171°47.2096′E
Start hole: 0415 h, 29 December 2009
End hole: 2300 h, 29 December 2009
Time on hole (d): 0.78
Seafloor (drill pipe measurement from rig floor, m DRF): 121.2
(APC mudline)
Distance between rig floor and sea level (m): 11.4
Water depth (drill pipe measurement from sea level, m): 109.8
Total depth (drill pipe measurement from rig floor, m DRF):
206.6
Total penetration (m DSF): 85.4
Total length of cored section (m): 83.4
Total core recovered (m): 84.43
Core recovery (%): 101
Total number of cores: 18
Hole U1354B
Position: 44°50.8367′S, 171°47.2069′E
Start hole: 2300 h, 29 December 2009
End hole: 1245 h, 30 December 2009
Time on hole (d): 0.57
Seafloor (drill pipe measurement from rig floor, m DRF): 124.8
(APC mudline)
Distance between rig floor and sea level (m): 11.4
Water depth (drill pipe measurement from sea level, m): 113.4
Total depth (drill pipe measurement from rig floor, m DRF):
202.0
Total penetration (m DSF): 77.2
Total length of cored section (m): 77.2
Total core recovered (m): 77.52
Core recovery (%): 100
Total number of cores: 15
1
Expedition 317 Scientists, 2011. Site U1354. In
Fulthorpe, C.S., Hoyanagi, K., Blum, P., and the
Expedition 317 Scientists, Proc. IODP, 317: Tokyo
(Integrated Ocean Drilling Program Management
International, Inc.).
doi:10.2204/iodp.proc.317.106.2011
2
Expedition 317 Scientists’ addresses.
Proc. IODP | Volume 317
Hole U1354C
Position: 44°50.8487′S, 171°47.2080′E
Start hole: 0700 h, 31 December 2009
End hole: 1200 h, 2 January 2010
Time on hole (d): 2.21
doi:10.2204/iodp.proc.317.106.2011
Expedition 317 Scientists
Seafloor (drill pipe measurement from rig floor, m
DRF): 124.8 (by proxy, Hole U1354B)
Distance between rig floor and sea level (m): 11.4
Water depth (drill pipe measurement from sea
level, m): 113.4
Total depth (drill pipe measurement from rig floor,
m DRF): 509.0
Total penetration (m DSF): 384.2
Total length of cored section (m): 319.2
Total core recovered (m): 133.37
Core recovery (%): 42
Total number of cores: 35
Integrated Ocean Drilling Program (IODP) Site
U1354 (proposed Site CB-02A) is located on the middle outer shelf (112 m water depth) within the Canterbury Bight between landward shelf Site U1353
(proposed Site CB-01A) and outer shelf Site U1351
(proposed Site CB-03B) within the Canterbury Basin
drilling transect. Site U1354 is located on dip seismic
Profile EW00-01-66 and crossing strike Profile EW0001-07a (Figs. F1, F2).
The philosophy behind the transect approach is discussed in “Background and objectives” in the “Site
U1351” chapter. Site U1354 occupies an intermediate position in the shelf portion of the transect. Lithologies and paleoenvironments were therefore expected to be intermediate between those found at
Sites U1351 and U1353.
Site U1354 penetrates a middle Miocene to Holocene
section containing seismic sequence boundaries U8–
U19 (Lu and Fulthorpe, 2004). All sequence boundaries were penetrated landward of their rollovers or
paleoshelf edges with the goal of recovering proximal facies, yielding evidence of shallow-water deposition, and providing optimal paleowater depths
from benthic foraminiferal biofacies.
The principal objectives at Site U1354 were
1. To sample facies landward of rollovers of progradational seismic sequence boundaries U8–U19
and in particular to use benthic foraminiferal biofacies to estimate paleowater depths both above
and below sequence boundaries in order to calculate eustatic amplitudes using two-dimensional
backstripping.
2. To investigate the facies, paleoenvironments,
and depositional processes associated with the sequence stratigraphic model in a proximal setting
on a prograding continental margin where sequence architecture is well constrained by seismic imaging.
Proc. IODP | Volume 317
Site U1354
Operations
Transit to Site U1354
After a 7 nmi transit from Site U1353, the R/V
JOIDES Resolution was positioned over Site U1354 at
2320 h (all times are ship local time, Universal Time
Coordinated [UTC] +13 h) on 28 December 2009. At
0001 h on 29 December, the positioning beacon (FSI
BAP-547W, SN 1025, 14.0 kHz, 200 dB) was deployed. The position reference was a combination of
Global Positioning System (GPS) and an acoustic
beacon on the seafloor, weighted heavily toward the
acoustic beacon (80%).
Site U1354 overview
Three holes were cored with the advanced piston
corer (APC)/extended core barrel (XCB) coring systems at Site U1354 (Table T1). The third hole
(U1354C) was drilled to 65 m drilling depth below
seafloor (DSF) with a center bit installed to advance
the hole after severe weather ended Hole U1354B.
Hole U1354C was then cored to 384.2 m DSF. Logging of Hole U1354C was successfully completed using a special tool configuration that combined the
natural gamma ray tool, the sonic tool, and the resistivity tool. The Sediment Temperature (SET) tool was
deployed twice without success. The type of formation encountered proved too difficult for our temperature measurement tools. Overall recovery for
Site U1354 was 100% with the APC coring system
and 39% with the XCB system. The total cored interval for Site U1354 was 479.8 m, with 294.50 m (61%)
of recovery.
Hole U1354A
Rig floor operations commenced at 2345 h on 28 December when the vessel was stabilized over Hole
U1354A. Coring in Hole U1354A (109.8 m water
depth) began at 0415 h on 29 December, with 3.8 m
of mudline core establishing the seafloor at 121.2 m
drilling depth below rig floor (DRF). APC coring continued through Core 317-U1354A-19H to 85.4 m
DSF using nonmagnetic coring assemblies. A 2 m
section (64.9–66.9 m DSF) had to be drilled to advance through a section of shells and shell fragments. Core orientation was measured on the first
three cores, but hard formation and incomplete piston strokes prompted a decision to remove the tool.
Temperature measurements were not attempted in
this hole because hole conditions were poor and
waiting for 10 min without circulation in shallow
water was deemed too risky. Overall recovery for
2
Expedition 317 Scientists
Hole U1354A using the APC coring system was
84.43 m (101%). The drill string was pulled back to
the seafloor, and the bit cleared the seabed at 2300 h
on 29 December, officially ending the hole.
Hole U1354B
The vessel was offset 20 m south of Hole U1354A,
and Hole U1354B was spudded at 2330 h. Hole
U1354B was piston cored to 77.2 m DSF, with a total
core recovery of 77.52 m (100%). Because of the
rough piston coring conditions noted in Hole
U1354A, the core orientation and downhole temperature tools were not deployed. Coring was terminated because highly variable winds from the south
caused positioning problems. The ship could not be
maintained in its required watch circle, so we decided to wait for the weather to improve. The drill
string was tripped back to just above the seafloor,
and the bit cleared the seafloor at 1245 h on 30 December, ending Hole U1354B.
Hole U1354C
Hole U1354C officially began at 0700 h on 31 December when the vessel could again be maintained
in its watch circle over the new location. The ship
was offset 20 m south of Hole U1354B, and coring
began at 0715 h on 31 December. The hole was
drilled with the center bit installed to 65 m DSF before two APC cores were taken. The core liner shattered on the second attempt, and the APC system
was replaced with the XCB system to core through a
particularly dense layer of shells. Core recovery with
the XCB was initially very good but deteriorated
downhole. Coring with the XCB continued to 384.2
m DSF (Core 317-U1354C-36X). The total cored interval for Hole U1354C was 319.2 m, with 133.37 m
of core recovered (42%).
The hole was swept clean with a 50 bbl high-viscosity mud sweep and displaced with 320 bbl of highviscosity 10.5 ppg logging mud. The drill string was
tripped out of the hole to 225 m DRF (100 m DSF). A
special logging string was made up in order to combine all basic sensors without nuclear sources into a
single run. The tool string included resistivity (Dual
Induction Tool [DIT]), sonic compressional and
shear velocity (Dipole Sonic Imager [DSI]), and natural gamma ray spectroscopy (Hostile Environment
Natural Gamma Ray Sonde [HNGS]) tools. The tool
string was rigged up in the early morning of 2 January 2010 and tagged the bottom of the hole at ~505
m wireline log depth below rig floor (WRF). A short
“repeat section” was recorded from there to ~440 m
WRF. The tool string was returned to total depth,
and then a main pass from total depth up to the sea-
Proc. IODP | Volume 317
Site U1354
bed was recorded. The drill string was tripped back to
275 m DRF, and a 12 bbl, 14 ppg cement plug was
pumped. At 0615 h on 2 January, the logging tools
were rigged down, the drill string was tripped to the
surface, and the bottom-hole assembly (BHA) was
broken down and secured for transit. When the beacons were recovered and the rig was secured for transit, operations in Hole U1354C, at Site U1354, and
on Expedition 317 ended at 1200 h on 2 January,
and the vessel departed for the 24 h transit to Wellington.
Lithostratigraphy
Sediment descriptions at Site U1354, located between Site U1351 on the outer shelf and Site U1353
on the inner shelf, are based on three holes at this
site. Holes U1354A and U1354B were drilled with the
APC to 85.4 and 77.2 m core depth below seafloor
(CSF-A), respectively (unless otherwise noted, all
depths in this section are reported in m CSF-A). Hole
U1354C was drilled without coring to 65 m. The
APC system was then used to recover Cores 317U1354C-2H and 3H before the hole was drilled with
the XCB to a total depth of 384.2 m. Holes U1354A
and U1354B had a sediment recovery rate of 100%,
and Hole U1354C had a recovery rate of 41.8% (Fig.
F3). These rates are slightly exaggerated given that
some cores contain downhole material from cave-in
or flow-in (at the base of some cores).
Lithologic descriptions at this site lack the X-ray diffraction (XRD) data used in other site descriptions,
and similarly coulometry data are limited because of
the short time frame available for drilling and the
short transit at the end of the expedition.
The succession was divided into two lithologic units,
with Unit I being further divided into two subunits
(Table T2). Unit I (0–250 m) covers the Holocene to
early Pliocene and is characterized by a highly heterogeneous assemblage of facies dominated by mud,
with more heterogeneity evident in Subunit IA and a
more repetitive succession of alternating facies occurring in Subunit IB. Unit II is early Pliocene in age
and is primarily composed of mud, sandy mud,
muddy sand, and rare marl layers, distinguished
from Unit I by the generally low calcareous content
of the layers.
The dominant mud lithology is interpreted as a shelf
facies and likely represents the deepest water depth
during deposition, so that the increasing dominance
of mud facies downhole represents progressively
deeper depositional environments. The other lithofacies present in Unit I are interpreted as shoreface or
estuarine to inner shelf, possibly representing either
3
Expedition 317 Scientists
transgressive shoreface deposits or sediment deposited immediately after the transgression (see Browne
and Naish, 2003).
Description of lithologic units
Unit I
Intervals: Cores 317-U1354A-1H through 19H;
317-U1354B-1H through 15H; and 317U1354C-2H to Section 23X-CC, 20 cm
Depths: Hole U1354A: 0–85.43 m (total depth);
Hole U1354B: 0–77.52 m (total depth); and Hole
U1354C: 65–250.86 m
Age: Holocene to early Pliocene
Unit I is divided into Subunits IA and IB, which are
described below. Unit I is heterolithic but characterized by its overall muddy composition (Figs. F4, F5).
The uppermost part of the unit is well defined in
Holes U1354A and U1354B (Fig. F6). The dominant
lithology is dark greenish gray homogeneous mud
(Fig. F7) with <10% very fine sand beds/laminae.
Shells are either rare and scattered or abundant and
locally concentrated in layers as thick as 15 cm and
beds ~1 m thick. Shells are dominated by the gastropod Stirocolpus and lesser amounts of Tawera or other
bivalves, including oysters. Some shell layers and
beds contain shell fragments that range in size from
a few millimeters to several centimeters. Contacts between shell layers are, for the most part, gradational
with the overlying and underlying mud. Bioturbation is common and has an ichnofabric index of 1
(no bioturbation) to 5 (complete bioturbation). Locally, the mud fraction can be clay rich or clay (see
“Lithostratigraphy” in the “Methods” chapter for
definitions), the latter either forming centimeterthick, sharp-based beds or occurring as mottles
within the mud (Fig. F8C).
Subordinate lithologies include
• Centimeter- to decimeter-thick beds of greenish
gray and dark greenish gray very fine sandy shelly
mud to shell hash (Fig. F8A) mixed with siliciclastic grains (very fine to medium sand) and abundant Stirocolpus, Tawera, echinoid spines, barnacle
plates, bivalves, gastropods, and rare pebbles of
graywacke sandstone as large as 1.5 cm in diameter and limestone as long as 7 cm.
• Very dark greenish gray, well-sorted, very fine to
fine (mostly fine), highly micaceous lithic sand
with broken shells (Fig. F9). Typically, the sand
has a soft and soupy appearance in the core and
may have been partially fluidized during drilling.
• Sandy marl (Fig. F8A–F8B), which occurs as a 4 m
thick deposit in the uppermost part of the site
(Cores 317-U1354A-1H and 317-U1354B-1H), presumably of Holocene age. The sandy marl is
Proc. IODP | Volume 317
Site U1354
homogeneous, dark greenish gray, and micaceous,
with very fine to fine sand.
• Dark greenish gray clay-rich mud (Fig. F8D) with
intercalated, normally graded sand laminations.
Each lamination has a sharp base and is composed
of very fine to fine, well-sorted, dark gray sand
that is slightly micaceous and of possible Torlesse
provenance. Rare, angular graywacke clasts (5–7
mm in diameter) are present in the mud.
• Bluish gray, poorly sorted, very fine to coarse
sandy mud with abundant shells and shell fragments that range in size from 0–1 mm to 2 cm.
• Calcareous muddy sand to sandy mud and concretions (Fig. F9D).
A considerable amount of potential cave-in material
was recovered in Holes U1354A and U1354B below
Sections 317-U1354A-5H-CC (14.3 m) and 317U1354B-4H-1 (12.1 m). The cores are typically
capped by a shell-hash lithology in the top few decimeters that transitions, often through a soupy, mudrich interval, into what is considered to be in situ
sediment. Despite the issue of cave-in and flow-in, a
discernible stratigraphy of mud with subordinate
clay, sand, sandy marl, and sandy mud is evident.
Muddy shell hash and shelly mud cave-in first occur
at the top of Core 317-U1354B-4H. Nannoplankton
biostratigraphy shows that shell hash is definitely
cave-in in Core 317-U1354A-11H (55 m). It is possible that the shell hash from ~15 m to the occurrence
listed above may represent in situ sediment.
Figure F6 illustrates the subtle variations in lithology,
grain size, and shell content between Holes U1354A
and U1354B, even though these holes are located 20
m from each other. Holes U1354A and U1354B can
be correlated based on prominent sand and shelly
mud beds. The sand intervals are thinner in Hole
U1354B than in Hole U1354A. However, this could
be an artifact of recovery because sand can be easily
washed out from the bottom of APC cores. Both
holes contain numerous shell beds, and a particularly thick example is present from 40 to 50 m in
Hole U1354A and from 36 to 46 m in Hole U1354B
(Fig. F6). In general, both holes show a coarseningupward trend dominated by sand in the uppermost
30 m.
Subunit IA
Intervals: Cores 317-U1354A-1H through 19H;
317-U1354B-1H through 15H; and Sections
317-U1354C-2H-1, 0 cm, to 12X-1, 110 cm
Depths: Hole U1354A: 0–85.43 m (total depth);
Hole U1354B: 0–77.52 m; and Hole U1354C:
65–145.8 m
Age: Holocene to mid-Pliocene
4
Expedition 317 Scientists
Subunit IA is more heterolithic and contains dark
greenish gray to olive-gray calcareous muddy sand,
sandy marl, and homogeneous marl (e.g., Cores 317U1354A-1H and 317-U1354B-10H; Fig. F9A–F9B)
and very dark gray, massive, quartz-rich, very well
sorted very fine to fine sand (e.g., Cores 317U1354A-7H and 317-U1354B-10H; Figs. F6, F8B).
This subunit also contains examples of sharp, bioturbated contacts between very fine muddy sand (sometimes calcareous) above and silty mud below (e.g.,
Sections 317-U1354B-13H-2 and 317-U1354C-12X-1;
Fig. F9D).
Subunit IA at Site U1354, in common with the corresponding unit at all three other sites, is characterized
by lithologic heterogeneity. The common lithologies
are calcareous mud and calcareous sandy mud,
which alternate with greenish gray shelly marl and
sandy marl. Minor lithologies include very fine to
fine sand, calcareous silty very fine to fine sand, and
clay-rich mud. Most lithologies in Unit I contain
>10% carbonate components based on smear slide
estimates (Fig. F10) and the identification of sand- to
gravel-sized bioclasts in the cores.
The terrigenous components identified in smear
slides are dominated by quartz and feldspar, micas
(including chlorite, muscovite, and occasionally biotite), rock fragments, ferromagnesian minerals (probably mainly hornblende), and dense minerals (zircon
and epidote, among others). Rock fragments identified at this site, in common with previous sites, include fine-grained metasedimentary and metamorphic rock fragments.
Authigenic components include varying amounts of
opaque minerals (infilling foraminifers, framboids,
nodules, and alteration of mica) and carbonate (incipient micritic/microcrystalline cement and alteration). Glauconite is common in a few horizons, notably around Section 317-U1354C-8X-CC, where
unusual turquoise patches, as well as corroded shells
and pale gray muddy sediment, were observed. The
glauconite observed here is different from the majority of that observed at previous sites in that it appears to be composed primarily of the alteration of
shell fragments (and possibly opaque minerals or
mica grains) rather than transported grains. Layers
with unusually high alteration or carbonate cements
occur in association with sharp lithologic contacts,
either in the shelly sandy layers above the contact
(e.g., Sample 317-U1354C-10X-1, 70 cm) or in the
mud layers immediately below the contact (e.g.,
Sample 317-U1354A-11H-3, 37 cm).
Biogenic components identified in smear slides are
dominated by undifferentiated bioclasts (fragments
of shells) in the sandy facies and by nannofossils and
Proc. IODP | Volume 317
Site U1354
didemnid ascidian spicules in the muddy facies.
Most shells, especially foraminifers, are altered, with
calcite crystals growing on both the outside and inside of the shells.
All of the thin sections examined are from Subunit
IA and belong to two different lithologies. The first
lithology is sandy marlstone, in which cementation
of the in situ sediment resulted in nodules or concretions. The cement comprises carbonate, either as matrix replacement or pore-filling cements (rhombic
shapes are common). The other sediment components are generally the same as those in the surrounding sediments, with a slightly higher proportion of bioclasts and a lack of nannofossils
(presumably from recrystallization). In one case (Section 317-U1354A-15H-CC), the cemented material
comprises the interior of a shell, where cement is
concentrated inside and around the shell, creating a
nodule.
The second lithology identified in thin section is unusual and occurs in two isolated, bored cobbles, one
of which was found in a core catcher sample (Section
317-U1354A-15H-CC) and the other in the shelly,
sandy layer immediately above the Brunhes/Matuyama boundary (probably an unconformity; Sample
317-U1354B-13H-2, 77–78 cm; see “Paleomagnetism”). The cobbles are rounded and dark gray and
have calcareous encrustations on the outside and extensive borings on their surfaces. The lithology of
these samples is pyritized sandy or silty limestone.
The matrix of each has been almost completely replaced by micrite, and opaque minerals (probably
pyrite) occur throughout the matrix, concentrated
around the margins of the borings. Sediment inside
the borings is consistent with the surrounding sediment, but the lithified sediment inside the cobble itself is not consistent with the surrounding unlithified sediment. One of the differences noted is that
although bioclasts (shell fragments and common foraminifers) occur within the limestones, specific bioclasts (mostly didemnid ascidian spicules) common
to the surrounding and overlying sediments are not
present. Burrowing in the sediment prior to cementation can be inferred by the occurrence of patches
with no detrital grains, different cement texture, or
randomly oriented detrital grains.
Subunit IB
Interval: Sections 317-U1354C-12X-1, 110 cm,
through 23X-CC, 20 cm
Depth: 145.8–250.86 m
Age: mid-Pliocene to early Pliocene
The Subunit IA/IB boundary is marked by a decrease
in the percentage of ferromagnesian minerals and
5
Expedition 317 Scientists
glauconite, as estimated in smear slides (Fig. F10).
Subunit IB has a less varied lithology than that in
Subunit IA; however, except for the above-mentioned differences, the overall composition observed
in the smear slides is very similar. In this unit, the
gray mud layers do not, in general, have very high
carbonate component percentages and are only
rarely calcareous.
Subunit IB lacks the aforementioned olive-gray marl
and massive sand beds found in Subunit IA and is
characterized by more repetitive assemblages of facies (e.g., Cores 317-U1354C-19X and 21X) that consist of (1) homogeneous greenish gray mud, which
appears to be more clay rich (e.g., Sections 317U1354C-18X-1 and 14X-1; Fig. F8D) than that in
Subunit IA and which also contains a minor calcareous component, and (2) greenish gray to gray calcareous sandy mud to sandy marl that often contains
calcareous concretions (e.g., Section 21X-CC).
Unit I/II boundary
The main difference between Units I and II is the calcareous nature of each (Fig. F10): Unit II contains far
fewer calcareous beds than Unit I and is dominated
by a monotonous succession of gray sandy mud. The
boundary is placed below the last highly calcareous
layer and at the base of a sandy interval in the core.
Unit II
Interval: Sections 317-U1354C-23X-1 through
36X-CC
Depth: 250.10–375.38 m (total depth)
Age: early Pliocene
The sediments of Unit II are primarily composed of
mud, sandy mud, muddy sand, and rare marl. In
Unit II, the gray mud layers are not very calcareous,
but they are also infrequent, and the unit is dominated by sandy mud (sometimes calcareous sandy
mud). Greener layers with a sandier texture are still
present. The percentage of carbonate in sandier
greener layers, as estimated by smear slide observation, is much lower in Unit II than in Unit I and
rarely exceeds 15%. The dominant lithology is gray,
homogeneous silty mud with rare scattered shells.
Bioturbation has an ichnofabric index of 1 (no bioturbation) to 4 (heavy bioturbation).
Correlation with wireline logs
Wireline logging data and physical property measurements were not processed sufficiently by the end
of the expedition to enable detailed correlation of
the logs to the described lithostratigraphy.
Proc. IODP | Volume 317
Site U1354
Downhole trends in sediment composition
and mineralogy
As at the other shelf sites, the compositional trends
are gradational from Unit I to Unit II, but the lack of
shipboard XRD data limits the description of downhole mineralogical trends. Unit I composition is
highly variable depending on the lithology, which is
consistent with the heterolithic nature of the unit.
Quartz/feldspar, carbonate, clays, micas, ferromagnesian minerals, glauconite, rare dense minerals, and
siliceous bioclasts occur throughout Unit I, but their
concentrations are quite variable (Figs. F10). The carbonate, siliceous bioclast, and ferromagnesian mineral contents are notably higher in Subunit IA relative to deeper in the hole. However, no discernible
downhole trends in composition are apparent in
Subunit IB, and there are no recognizable changes in
composition between Subunit IB and Unit II.
Description of lithologic surfaces and
associated sediment facies
Because of time restrictions on board ship, surfaces
were only examined close to the predicted depths of
seismic sequence boundaries; therefore, the lithologic surfaces identified here are implicitly linked to
the predicted occurrences of sequence boundaries
identified on the seismic (Lu and Fulthorpe, 2004). A
similar approach was used on board Ocean Drilling
Program (ODP) Legs 150 and 174A, the objectives of
which were also the study of sea level changes. Postcruise study will attempt to clarify the exact relationship of all lithologic surfaces and facies associations
to sea level changes and seismic stratigraphy. The
numbering system used in the site chapters, tables,
and summary diagrams comprises a hole-specific
prefix and a surface designation (e.g., U1354A-S1)
that links each surface to a seismic sequence boundary; therefore, these lithologic surfaces and associated sediments are thought to be correlative between
sites across the transect.
Definitions of Type A–C surfaces are detailed in
“Lithostratigraphy” in the “Site U1352” chapter.
Type A contacts and facies associations (sharp, commonly bioturbated basal contacts with overlying
muddy shelly sand or sand beds ~1 m thick) were
identified in Holes U1354A–U1354C. This type of
contact and facies association dominates the uppermost 250 m of sediments at this site. These contacts
were classified as lithologic surfaces U1354A-S1 to
U1354A-S5, U1354B-S1 to U1354B-S5, and U1354CS5 to U1354C-S8. One major characteristic of Site
U1354 sediments is that in several intervals two or
6
Expedition 317 Scientists
three Type A contacts and facies associations that
could be used for correlation occur in one core. In
such cases, the thickest bed was chosen.
Surfaces U1354A-S1 to U1354A-S4 and
U1354B-S1 to U1354B-S4
Type A lithologic surfaces are present in the uppermost 64 m in Holes U1354A and U1354B (see Table
T3 for associated depth intervals), revealing a very
good correlation between holes. Surface depths differ
across holes by as much as 4.8 m for U1354A-S4 and
U1354B-S4 (Table T3). As at shelf Sites U1353 and
U1351, very fine, well-sorted sand forms beds as
thick as 9 m, and these beds are associated with
U1354A-S1 and U1354B-S1 (base of shelly sand
layer) and U1354A-S2 and U1354B-S2 (debatable top
of liquefied sand interval) (Fig. F11). The strongest
correlation between holes is for surfaces U1354A-S4
and U1354B-S4, which were dated and correlated
across holes by the Brunhes/Matuyama boundary.
Surfaces U1354A-S5, U1354B-S5, and
U1354C-S5
Site U1354 is the only location at which three adjacent holes recovered surface S5 at comparable depths
ranging from 74 to 80 m (Table T3). Muddy shelly
Type A sand was recovered in each hole. However, a
sharp burrowed contact was only recovered in Hole
U1354C.
Surfaces U1354C-S5.1 and U1354C-S6
These two Type A surfaces are characterized by
muddy shelly sand above a sharp contact that is bioturbated beneath. Surface U1354C-S5.1 is at 94 m
and U1354C-S6 is at 118 m. (Table T3). The Pliocene/Pleistocene boundary was picked by biostratigraphy between 122 and 133 m, below U1354C-S6.
Above this, the sediment age is between 1.73 and
1.81 Ma (NN) and below this the age of the sediment
is >2.78 Ma (NN).
Surfaces U1354C-S7, U1354C-S7.1 and
U1354C-S8
A particular characteristic of outer shelf Site U1354 is
the occurrence of several Type A contacts and facies
associations within a few meters of each other. For
example, sharp, burrowed contacts between shelly
sand above and mud below that could be assigned to
U1354C-S7 were found at 132, 146, and 163 m.
U1354C-S7.1 is characterized by shelly sandy mud
with a gradational lower contact containing concretions. This contact was placed at 181 m.
U1354C-S8 is another example of multiple lithologic
contacts occurring in a short interval of stratigraphy.
Proc. IODP | Volume 317
Site U1354
In all cases, the associated sediments are composed
of shelly sandy marl. The sediment is more calcareous, and increased diagenesis and concretions are associated to this surface. Several lithologic contacts
and associated sediments linked to U1354C-S8 are
present at 218, 222, and 244 m.
Discussion and interpretation
Interpretation of Unit I
Unit I represents a heterolithic assemblage whose deposition throughout was likely influenced by fluctuating sea level. The Type 1 and 2 cycles, as described
in “Lithostratigraphy” in the “Site U1351” chapter,
also occur at Site U1354.
The dominant homogeneous mud lithology is interpreted as a shelf facies and likely represents the deepest water depth during deposition. Benthic foraminifers in Subunit IA indicate fluctuations between
estuarine or subtidal and middle shelf environments
between 0 and 30 m (Cores 317-U1354A-7H and
317-U1354B-8H) and generally inner shelf to outer
shelf environments (see “Biostratigraphy”). Intercalated, gray clay beds may represent episodic fluxes of
fine-grained sediment derived from fluvial or glacial
discharges.
We interpret the other lithologies within Unit I as
shoreface or estuarine to inner shelf, particularly in
the basal portions of the Type I and II cycles deposited during transgressive phases. We suggest that
these lithologies represent either transgressive
shoreface deposits or sediment deposited immediately after the transgression (Browne and Naish,
2003; see “Lithostratigraphy” in the “Site U1351”
chapter). Shell-hash intervals likely formed in a
shoreface and/or beach setting, and were probably
also a transgressive shoreface deposit. The green
sandy shelly mud may represent periods of late highstand and regression, when more calcareous sediment was deposited and perhaps when terrigenous
sediment diminished. These conclusions are similar
to our interpretation of lithologies within Unit I at
Sites U1351 and U1353 (see “Lithostratigraphy” in
the “Site U1351” chapter and “Lithostratigraphy”
in the “Site U1353” chapter).
Interpretation of Unit II
Poor core recovery in Unit II may have resulted in a
bias toward the recovery of muddy lithologies at the
expense of other lithologies. The generally muddy
character of the sediments means that they are difficult to interpret from a sedimentologic perspective.
Benthic foraminifers indicate depositional water
depths that range from inner to outer shelf (see
“Biostratigraphy”).
7
Expedition 317 Scientists
The generally mud-rich nature of the unit suggests a
relatively quiet depositional setting on a shelf below
a fair-weather wave base. Muddy sand may represent
periods when more terrigenous sediment was supplied from the margin. Biostratigraphy reveals significant hiatuses (e.g., during the late Pliocene; see
“Biostratigraphy”) and suggests considerable periods of erosion that were likely caused by sea level
and/or tectonic fluctuations that affected the shelf
environment.
Interpretation of lithologic surfaces and
associated sediment facies
Correlation at Site U1354 was found between Type A
contacts and facies associations and the predicted
depths of seismic sequence boundaries (Table T3).
These lithologic contacts were found within 2–30 m
of the predicted depths of sequence boundaries (Fig.
F12). In some cases, several contacts and facies potentially correlate to each respective sequence
boundary.
Surfaces U1354A-S1 to U1354A-S4 and U1354B-S1 to
U1354B-S4
These surfaces are correlated to seismic sequence
boundaries U19, U18, U17, and U16. The depths at
which these surfaces occur and the predicted depths
of U19–U16 exhibit good correlation, with minor
offsets of 5 m for U1354A-S3 and U1354B-S3 and
U1354A-S4 and U1354B-S4. The Brunhes/Matuyama
boundary was located and correlated across Holes
U1354A and U1354B between 65 and 69 m, and the
paleomagnetic age further contributed to the correlation of surfaces U1354A-S4 and U1354B-S4.
Surfaces U1354C-S5, U1354A-S5, U1354B-S5, U1354CS5.1, and U1354C-S6
Type A surfaces and facies associations associated
with U1354C-S5 were also identified in Holes
U1354A and U1354B. These surfaces occur in the
general depth range of U15, which has a predicted
depth of 79 m. Surface U1354C-S5 was picked at 75
m, U1354B-S5 was picked at 74 m, and U1354A-S5
was picked at 80 m. U1354C-S5.1 is correlated to
U14, which has a predicted depth of 93 m. This surface is also present at Site U1352, where it is also correlated to U14. U1354C-S6, located at 118 m, is correlated to U13, which has a predicted depth of 121
m.
Surfaces U1354C-S7, U1354C-S7.1, and U1354C-S8
Type A contacts and facies associations related to
U1354C-S7 occur at 132, 146, and 163 m. The lithologic surface at 146 m is correlated to U12 at 156 m.
U1354C-S7.1 at 181 m is correlated to U11 at 177 m.
Proc. IODP | Volume 317
Site U1354
Hole U1354C is the only location at which a lithologic surface was correlated to U11. Four Type A deposits (at 218, 222, and 244 m) are related to surface
U1354C-S8 and are potential lithologic surfaces of
correlation for U10 at 211 m. The surface at 218 m
has been tentatively selected. Future studies will investigate in more detail the role of contrasting lithologies, overlying strata thicknesses, the number of
events, and other potential sources that may generate seismic impedance contrast and acoustic signal.
Biostratigraphy
Holocene to late early Pliocene biostratigraphy of
Site U1354 was based on the shipboard study of calcareous nannofossils, diatoms, and planktonic and
benthic foraminifers in core catcher samples from
Holes U1354A–U1354C (Table T4; Fig. F13). Additional intracore samples were taken from selected
cores to address specific age and paleoenvironmental
questions using calcareous nannofossils. All microfossil groups were represented throughout the cored
section except for diatoms, which were found only
in a few Pleistocene samples. All depths in this section are reported in m CSF-A.
Holocene to Pleistocene sections from Samples 317U1354A-1H-CC, 0 cm, through 19H-CC (3.78–85.38
m), 317-U1354B-1H-CC through 15H-CC (4.06–
77.25 m), and 317-U1354C-2H-CC through 10X-CC
(72.57–127.79 m) were primarily dated and divided
into Zones NN21–NN19 using calcareous nannofossils. Two hiatuses were identified with nannofossil
dating: (1) an intra-Pleistocene hiatus between Samples 317-U1354A-15H-CC and 17H-CC (76.20–80.16
m) and between 317-U1354B-15H-1, 15 cm, and
15H-1, 39 cm (73.65–73.89 m), where ~0.3 m.y. was
missing, and (2) a hiatus at the base of the Pleistocene between Samples 317-U1354C-9X-CC and 10XCC (122.20–133.37 m), where ~1 m.y. was missing.
Another potential hiatus was identified on the basis
of calcareous nannofossil dating and magnetostratigraphic data in Holes U1354A and U1354B at 69.90
and 64.75 m, respectively.
The Pliocene section between Samples 317-U1354C10X-CC and 36X-CC (133.37–375.33 m) was poorly
dated, but calcareous nannofossil and planktonic
foraminifer biostratigraphy suggested an age of middle Pliocene (older than 2.78 Ma, calcareous nannofossils) to late early Pliocene (younger than 4.3 Ma,
planktonic foraminifers). There was no biostratigraphic evidence for the late Pliocene, which was
probably missing at the level of the Pleistocene–Pliocene hiatus.
Benthic foraminiferal abundances were generally indicative of subtidal to middle shelf depths through8
Expedition 317 Scientists
out the Pleistocene, and planktonic foraminifers suggested that deposition occurred generally under
sheltered, inner neritic conditions with short-lived
excursions to outer neritic and extraneritic conditions. Pliocene deposition occurred generally at inner shelf water depths (and possibly middle shelf
depths) under sheltered, inner neritic conditions.
Calcareous nannofossils
Nannofossil assemblages at Site U1354, located on
the outer shelf, were typically common to abundant
and moderately to well preserved (Table T5). The
Pleistocene succession was robustly dated by nannofossil biostratigraphy (Table T4). Although standard
zonal markers were absent for the Pliocene section,
the Reticulofenestra lineage provided crude, though
critical, age control for this interval.
Holocene–Pleistocene
Although not identified biostratigraphically, the base
of the Holocene was tentatively placed at Section
317-U1354A-2H-1, 25 cm (4.03 m), where there was
a distinct lithologic change between greenish gray
marly sands and gray calcareous muds.
The lowest occurrence (LO) of Emiliania huxleyi (0.29
Ma; base of Zone NN21) was observed between Samples 317-U1354A-6H-4, 0 cm, and 6H-CC (20.80–
24.25 m) and between 317-U1354B-7H-CC and 8HCC (26.50–33.45 m). The discrepancy in the location
of this datum between Holes U1354A and U1354B is
most likely due to the rare nature of this species at its
inception and the paucity of nannofossils in the fine
sands in Samples 317-U1354A-6H-CC and 7H-CC
(24.25–31.33 m).
The highest occurrence (HO) of zonal marker Pseudoemiliania lacunosa (0.44 Ma; top of Zone NN19)
was identified between Samples 317-U1354A-12H-1,
6 cm, and 12H-6, 31 cm (56.36–64.11 m), and between 317-U1354B-11H-CC and 12H-CC (57.73–
62.44 m).
An intra-Pleistocene hiatus was noted between Samples 317-U1354A-15H-CC and 17H-CC (76.20–80.16
m). In Hole U1354B, this hiatus was identified between Samples 317-U1354B-15H-1, 15 cm, and 15H1, 39 cm (73.65–73.89 m). In Hole U1354C, it was
observed between Samples 317-U1354C-2H-CC and
4X-CC (72.57–84.37 m). This was evidenced by the
occurrence of Gephyrocapsa >5.5 µm (1.26 Ma) at this
level and the absence of Reticulofenestra asanoi (0.91–
1.14 Ma), suggesting a hiatus of ~0.3 m.y. This hiatus
was similarly observed at Sites U1351 and U1353,
representing a robust surface of correlation between
these sites. In addition, the first paleomagnetically
reversed sediments were observed at 69.90 and
Proc. IODP | Volume 317
Site U1354
64.75 m (Holes U1354A and U1354B, respectively),
interpreted to represent the Brunhes/Matuyama
boundary (see “Paleomagnetism”). This boundary
is likely unconformable, although the amount of
time missing is unknown.
The HO of Helicosphaera sellii (1.34 Ma) was distinguished between Samples 317-U1354A-18H-CC and
19H-CC (80.33–85.38 m) and 317-U1354C-4X-CC
and 5X-CC (84.37–86.84 m). The LO of Gephyrocapsa
>4 µm (1.69 Ma) was recognized between Samples
317-U1354C-6X-CC and 7X-CC (97.76–105.86 m).
Lastly, the LO of Gephyrocapsa caribbeanica (1.73 Ma)
was observed between Samples 317-U1354C-8X-CC
and 9X-CC (111.56–122.20 m).
Pliocene
The Pliocene/Pleistocene boundary was biostratigraphically picked using calcareous nannofossils between Samples 317-U1354C-9X-CC and 10X-CC
(122.20–133.37 m). This pick correlates with a sharp
lithologic boundary noted in Core 317-U1354C-10X.
Site U1354 is the only expedition shelf site where
this boundary was definitely recovered. Nannofossil
abundances dropped dramatically across the Pliocene/Pleistocene boundary, a trend that was similarly observed at all three shelf sites. Sample 317U1354B-12H-CC (152.98 m) contained specimens of
Reticulofenestra ampla, the HO of which was dated at
2.78 Ma (Kameo and Bralower, 2000), suggesting an
unconformable
Pliocene/Pleistocene
boundary
where the late Pliocene is missing.
Nannofossil abundances in the Pliocene section were
variable and ranged from barren to common, and
preservation was generally good. Biostratigraphic
analysis of Site U1354 Pliocene sediments was particularly problematic for all microfossil groups because
of low abundances and/or the absence of biostratigraphic markers.
The HO of Reticulofenestra pseudoumbilicus (3.70 Ma)
occurred between Samples 317-U1354C-16X-CC and
17X-CC (183.20–192.75 m), defining the boundary
between the middle and early Pliocene. An expanded early Pliocene section was recovered from
Hole U1354C, and the lowermost core catcher contained specimens of the planktonic foraminifer
Globoconella puncticuloides s.s., restricting the age to
younger than 4.3 Ma. Bottom-hole age was therefore
constrained between 3.7 and 4.3 Ma.
Planktonic foraminifers
Holocene to late early Pliocene planktonic foraminiferal biostratigraphy of outer shelf Site U1354 was
based on the examination of core catcher samples
from Holes U1354A–U1354C (Tables T6, T7, T8, T9,
9
Expedition 317 Scientists
T10, T11). Absolute ages assigned to biostratigraphic
datums follow the references listed in Table T3 in the
“Methods” chapter. Planktonic foraminifers were
present in most samples in the Holocene to Pleistocene succession, but abundances were generally low.
Preservation was generally good. For planktonic foraminiferal abundance and interpretation of oceanicity, see Tables T6, T7, and T8 and Figure F14.
Holocene
Mudline samples (317-U1354A-1H-1, 0 cm [0.00 m],
and 317-U1354B-1H-1, 0 cm [0.00 m]) were characterized by abundant planktonic foraminiferal assemblages with common temperate taxa interpreted to
have been deposited under extraneritic conditions.
Although not identified biostratigraphically, the base
of the Holocene was tentatively located at Section
317-U1354A-2H-1, 25 cm (4.03 m), at the level of
distinct lithologic change between greenish gray
marly sands and gray calcareous muds.
Pleistocene
Planktonic foraminiferal assemblages in the Pleistocene sections of Samples 317-U1354A-1H-CC
through 19H-CC (3.78–85.38 m), 317-U1354B-1HCC through 15H-CC (4.06–77.25 m), and 317U1354C-2H-CC through 10X-CC (72.57–133.37 m)
were characterized by small, thin-walled neritic
forms. Deposition generally occurred under sheltered inner neritic conditions, except in Samples
317-U1354A-5H-CC (14.69 m), 8H-CC through 11HCC (38.14–60.14 m), and 317-U1354B-7H-CC
through 12H-CC (26.50–62.44 m), where planktonic
abundances ranged from 10% to 51%, indicating deposition under inner neritic to extraneritic conditions. Peaks in abundance were generally associated
with greenish gray sandy marls, and the assemblages
included common temperate forms such as Globoconella inflata, Neogloboquadrina incompta, and Orbulina
universa. Intervals of gray calcareous muds interbedded with sandy marls contained colder water assemblages, although the abundance of the subantarctic
species Neogloboquadrina pachyderma was seldom
high. Other species found in Pleistocene samples included abundant Globigerina bulloides, Globigerina
spp., Turborotalita quinqueloba and related forms, and
rare Globigerinita glutinata. Single specimens of the
subtropical species Globigerinoides ruber (Sample 317U1354B-12H-CC [62.44 m]) and Globigerinella aequilateralis (Sample 317-U1354A-11H-CC [60.14 m])
were also present.
Planktonic foraminifers were too few for reliable dating, but the presence of Truncorotalia truncatulinoides
Proc. IODP | Volume 317
Site U1354
in Samples 317-U1354A-8H-CC (38.14 m) and 10HCC (53.76 m) indicated that the uppermost part of
the section was younger than 1.1 Ma. The late Pleistocene, Haweran/Castlecliffian Stage boundary was
identified between Samples 317-U1354B-9H-CC and
10H-CC (41.46–50.29 m) on the basis of the HO of
benthic foraminifer Siphotextularia wairoana. Calcareous nannofossil dating supported this correlation.
The base of the Pleistocene was identified using calcareous nannofossil evidence between Samples 317U1354C-9X-CC and 10X-CC (122.20–133.37 m).
Pliocene
Pliocene planktonic foraminiferal abundances between Samples 317-U1354C-11X-CC and 36X-CC
(144.95–375.33 m) seldom reached >5% of the total
foraminiferal assemblage. Assemblages were generally composed of small, thin-walled neritic forms,
and diversity was low, except in Sample 317U1354C-21X-CC (240.77 m), where planktonic
abundance reached 21%. This sample included
abundant small Globigerina spp., Globigerina
bulloides, Neogloboquadrina pachyderma, and Nq. incompta. These species were also present in most of
the Pliocene section along with sporadic occurrences
of Turborotalita quinqueloba.
Several age-diagnostic species were also found in the
lower part of the Pliocene section, including Globoconella inflata and Gc. puncticuloides. The HO of Zeaglobigerina woodi (2.7 Ma) was noted between Samples
317-U1354C-27X-CC and 28X-CC (293.32–299.64
m), although calcareous nannofossil dating suggested that this bioevent was suppressed at this site.
The joint occurrence of Zg. woodi and Gc. puncticuloides in the lowermost Sample 317-U1354C-36X-CC
(375.33 m) indicated a late early Pliocene age of 2.7–
4.3 Ma for the hole bottom. Calcareous nannofossils
indicated that bottommost sediments were older
than 3.7 Ma, constraining the bottom-hole age to
3.7–4.3 Ma.
Benthic foraminifers
Sixty-five core catcher samples from Holes U1354A–
U1354C were examined for benthic foraminifers (Table T12). Three samples identified by nannofossil
biostratigraphy as caved (Table T5) were not used for
biostratigraphic and paleowater depth assessments.
Benthic foraminifer abundance varied throughout
the cored interval. Preservation was generally good
(but occasionally moderate or poor) in the Pleistocene and varied from poor to good in the Pliocene.
Three benthic foraminiferal bioevents were identified at Site U1354 (Table T4).
10
Expedition 317 Scientists
Holocene–Pliocene
The HO of Siphotextularia wairoana (0.34 Ma) was observed between Samples 317-U1354A-9H-CC and
10H-CC (46.88–53.76 m) and between 317-U1354B9H-CC and 10H-CC (41.46–50.29 m). Proxifrons advena (HO = ~0.4 Ma; Hayward, 2001) was also identified between Samples 317-U1354A-9H-CC and 10HCC (46.88–53.76 m). The HO of Bolivinita pliozea
(~0.6 Ma) was identified between Samples 317U1354A-12H-CC and 13H-CC (64.90–73.44 m) and
between 317-U1354B-10H-CC and 11H-CC (50.29–
57.73 m). This species was also observed in the uppermost core catcher sample in Hole U1354C (2HCC [72.57 m]), suggesting an age older than 0.6 Ma.
These ages are in general agreement with Pleistocene
ages derived from calcareous nannofossils. The HO
of Haueslerella parri (1.63 Ma) was seen in Sample
317-U1354C-12X-CC (152.98 m) below the Pliocene/Pleistocene boundary.
Paleowater depths
Estimated paleowater depths are given in Table T12
and Figure F15. The paleodepth zone classification is
given in Figure F7 in the “Methods” chapter.
In the Pleistocene section, two alternating benthic
foraminiferal assemblages were noted (Holes U1354A
and U1354B and Samples 317-U1354C-1H-1, 0 cm,
through 9X-CC [0–122.20 m]). One assemblage consisted mainly of Notorotalia inornata (shallow inner
shelf) and Elphidium charlottense (estuarine–subtidal)
associated with Zeaflorilus parri (shallow inner shelf),
suggesting a shallow inner shelf environment. The
other assemblage consisted of Notorotalia aucklandica
(inner shelf), Nonionella flemingi, and Anomalinoides
sphericus (middle outer shelf), implying a depositional environment as deep as outer shelf. Samples
317-U1354A-8H-CC through 11H-CC (38.14–60.14
m) and 317-U1354C-8X-CC (111.56 m) contained
the uppermost bathyal taxon Globocassidulina subglobosa. Paleowater depths exhibited high variability
from subtidal to outer shelf environments, with
maximum water depths in the late and earliest Pleistocene.
In the middle Pliocene section between Samples 317U1354C-10X-CC and 22X-CC (133.37–247.41 m),
benthic foraminifers were rare and poorly preserved.
Notorotalia flemingi, N. aucklandica, and N. inornata
(inner to middle shelf) were relatively common in
association with Bolivina spp. and Astrononion spp.,
suggesting inner shelf environments.
In the lower Pliocene section between Samples 317U1354C-21X-CC and 36X-CC (240.77–375.33 m),
the benthic assemblage was characterized by Notorotalia flemingi, N. aucklandica, N. inornata, and AsProc. IODP | Volume 317
Site U1354
trononion spp. (inner to middle shelf), together with
consistent occurrences of Uvigerina rodleyi (inner to
middle shelf; Hornibrook et al., 1989) and Anomalinoides sphericus (middle to outer shelf). This suggested middle shelf environments that shallow occasionally to inner shelf the early Pliocene.
Diatoms
Eighteen core catcher samples from Hole U1354A
were examined for diatoms (Samples 317-U1354A1H-CC through 19H-CC [3.78–85.38 m]) (Table
T13). Diatom samples were typically barren, except
in Sample 317-U1354A-2H-CC (12.26 m), where diatoms were common and moderately preserved. This
assemblage consisted of extant coastal taxa, along
with Paralia sulcata (>90% in abundance), resting
spores of Chaetoceros, a fragment of Triceratium spp.,
and Paralia sulcata. Rare resting spores were also
present in Samples 317-U1354A-4H-CC (14.30 m),
9H-CC (46.88 m), and 14H-CC (75.41 m).
All core catcher samples (317-U1354B-1H-CC
through 15H-CC [4.06–77.25 m] and 317-U1354C2H-CC through 36X-CC [72.57–375.33 m]) were barren of diatoms, except for Sample 317-U1354B-10HCC (50.29 m), which contained two valves of the
coastal species Paralia sulcata, as well as several
fragments from other indeterminate species (Table
T13).
Macrofossils
Macrofossils were examined in cored sediments from
all Site U1354 holes. Provisional identifications,
ages, and habitat preferences are provided in Table
T14.
Paleomagnetism
Paleomagnetic analyses at Site U1354 included measurement and partial demagnetization of natural remanent magnetization (NRM) of archive section
halves. No discrete samples from Site U1354 were
measured during shipboard analyses. All depths in
this section are reported in m CSF-A.
Section-half measurements
NRM was measured on archive section halves from
Holes U1354A–U1354C before and after demagnetization at 20 mT peak fields. Persistent flux jumps in
the superconducting rock magnetometer (SRM)
made measurements difficult at Site U1354. Many
section halves were measured several times before
readings were accepted. Because of the limited time
available, no acceptable measurement could be obtained for some sections, whereas for others only
11
Expedition 317 Scientists
NRM was recorded. In spite of this, a good record of
all three holes from Site U1354 was acquired.
Holes U1354A and U1354B have similar total depths,
and comparable records were obtained (Figs. F16,
F17). These relatively shallow holes were cored using
the APC system with nonmagnetic core barrels
throughout. Hole U1354C was drilled without coring for 65 m, at which point the APC system was
used with nonmagnetic core barrels to recover two
cores overlapping the bases of Holes U1354A and
U1354B. Coring continued with the XCB system to
total depth (Fig. F18).
NRM intensities typically vary between 10–2 and 10–3
A/m, and some anomalous peaks were recorded that
correspond to intervals of high magnetic susceptibility and cave-in. However, because of the difficulty of
taking measurements, many of these sections were
not measured in the SRM.
NRM inclinations from Site U1354 are typically
steeply positive (~80°), consistent with the drilling
overprint observed at previous sites. In the upper
parts of Holes U1354A and U1354B, these inclinations demagnetized at 20 mT to fairly steeply negative inclinations. Declinations throughout this interval are consistent within cores and variable between
cores, and they do not change direction significantly
with demagnetization, suggesting a negligible radial
drilling overprint. NRM declinations in Hole
U1354C are clustered in the northern hemisphere
and appear to display a drilling overprint associated
with the standard steel core barrels used with the
XCB coring system.
Reversed polarity was observed after 20 mT demagnetization toward the base of Holes U1354A (from
69.9 m) and U1354B (from 64.75 m) and at the top
of Hole U1354C. Inclinations remain steeply positive
after demagnetization. Where the normal/reversed
boundary is observed (Cores 317-U1354A-13H and
317-U1354B-13H), declinations change within the
core. In each hole, this boundary corresponds with a
lithologic boundary where green, muddy very fine
sand overlies gray silty mud at an irregular contact.
The polarity reversal observed at the base of Holes
U1354A and U1354B is the only one observed at Site
U1354. Older sediments were recovered from Hole
U1354C, but the drilling overprint imparted by the
XCB system was not removed by 20 mT demagnetization.
Magnetostratigraphy
Normal polarity sediments from the Brunhes Chron
were identified from 0 to 69.9 m in Hole U1354A
and from 0 to 64.75 m in Hole U1354B. These sediments are underlain across a lithologic boundary by
Proc. IODP | Volume 317
Site U1354
reversed polarity (Matuyama) sediments. The exact
amount of time represented by this boundary is unknown, but it includes the Brunhes/Matuyama
boundary (0.78 Ma) and is constrained by biostratigraphic evidence. Sediments overlying the boundary
are older than 0.44 Ma, as indicated by the HO of
Pseudoemiliania lacunosa between 56.36 and 64.11 m
in Hole U1354A and between 56.36 and 64.11 m in
Hole U1354B. Underlying sediments contain a nannofossil assemblage similar to that above the boundary (suggesting that any hiatus is brief) and lack Reticulofenestra asanoi (HO = 0.91 Ma).
Further nannofossil evidence suggests that the bases
of Holes U1354A and U1354B are older than 1.26 Ma
(HO Gephyrocapsa >5.5 µm is between 76.20 and
80.16 m in Hole U1354A and between 73.65 and
73.89 m in Hole U1354B). The Jaramillo normal
Chron (C1r.1n = 0.998–1.072 Ma) was not recorded
at Site U1354 and is likely represented by a second
hiatus. This concurs with the absence of Reticulofenestra asanoi (total range = 0.91–1.14 Ma).
Physical properties
At Site U1354, gamma ray attenuation (GRA) densitometer bulk density, magnetic susceptibility (loop
sensor; MSL), natural gamma radiation (NGR), and
P-wave logger (PWL) velocity were measured on
whole-round core sections from Holes U1354A–
U1354C. Discrete P-wave velocity measured using
the P-wave caliper (PWC) and P-wave bayonets
(PWB), moisture and density (MAD), and sediment
strength were measured on section halves from
Holes U1354B and U1354C. Magnetic susceptibility
(point sensor; MSP) and spectrophotometry and colorimetry were measured on cores from all three
holes. Measurements were made on APC and XCB
cores from Holes U1354A–U1354C to depths of 85.4
m (Section 317-U1354A-19H-5), 77.2 m (Section
317-U1354B-15H-5), and 384.2 m (Section 317U1354C-36X-2). Unless otherwise specified, all
depths in this section are reported in m CSF-A.
Gamma ray attenuation bulk density
GRA bulk density was measured at 2.5 cm intervals
(measurement time = 3 s). The raw data range from
–0.44 to 2.48 g/cm3 (Fig. F19). Variations in GRA
density may reflect varying sand content in the
cores.
A comparison of GRA densitometer data with MAD
data from Hole U1354B highlights key similarities
with Site U1353 (Fig. F20). In particular, MAD and
GRA densitometer results show the same multicore
trends, but GRA densitometer bulk density estimates
12
Expedition 317 Scientists
are consistently ~2%–3% higher than MAD bulk
density estimates. Although this is only slightly
above the expected error of the MAD method, such
an error should be randomly distributed about the
GRA results; thus, a systematic error either in MAD
measurements or in GRA densitometer calibration
must be present. As discussed in “Physical properties” in the “Site U1353” chapter, the most likely
problem is a calibration error with the GRA system.
Magnetic susceptibility
Magnetic susceptibility (MSL) was measured at 2.5
cm intervals (measurement time = 2 s), and magnetic
susceptibility (MSP) was measured at 5 cm intervals.
MSP measurements were made on all sections unless
drilling or surface disruption precluded the collection of meaningful results (Fig. F19).
Raw MSL data range from 1.1 to 275.0 instrument
units in Holes U1354A and U1354B and from 0.2 to
87.9 instrument units in Hole U1354C (Fig. F19). To
help illustrate key trends, the signal was cleaned using a Gaussian low-pass filter (30 passes; Fig. F19).
MSP magnetic susceptibility data at Site U1354 correlate well with data obtained from MSL measurements made on whole-round core sections (Fig. F19).
Both MSP and MSL magnetic susceptibility measurements show distinct variations in the uppermost
~170 m in all three holes, particularly the uppermost
80 m where core recovery was best.
The general cyclic pattern is very similar to that observed previously, particularly at Site U1351. Three
similar intervals between ~12 and ~76 m are characterized by a decreasing downhole trend followed by
an abrupt change to higher values at 26, 34, and
54 m (Hole U1354B). The abrupt changes at 34 and
54 m coincide with two changes in sulfate–methane
abundances in Hole U1354A (see “Geochemistry
and microbiology”). An interval of high magnetic
susceptibility between ~146 and ~152 m is not yet
understood. The upper end of this interval at ~146 m
might be associated with the Subunit IA/IB boundary
(see “Lithostratigraphy”). A slight change in magnetic susceptibility between ~68 and 70 m in Hole
U1354A and between 64 and 65 m in Hole U1354B
marks the Brunhes/Matuyama boundary and a hiatus
that is well documented in paleomagnetic, lithologic,
and biostratigraphic records (see “Lithostratigraphy,” “Biostratigraphy,” and “Paleomagnetism”).
The overlapping of Sections 317-U1354A-11H-3
through 11H-5 with 12H-1 through 12H-3 (between
56 and 60 m) can be explained by drilling disturbances in the lower part of Core 11H (Fig. F21). The
shell-hash interval in this core, as observed in the
Proc. IODP | Volume 317
Site U1354
conspicuously low values of magnetic susceptibility
and NGR for Hole U1354A, was not observed in Hole
U1354B.
Natural gamma radiation
NGR was measured at 10 cm intervals on all core sections as deep as 240 m in Hole U1354B (Section
36X). The measured values range from near zero to
>70 counts per second (cps), with higher values typically associated with muddy lithologies and lower
values associated with sands (Fig. F19).
A large-scale sinusoidal pattern of average NGR signal is apparent downhole, with ~70 cps peaks at ~14
and 215 m that are separated first by a gentle decline
to ~20 cps at ~75 m, followed by a gentle increase
again from ~75 to 215 m. The change from declining
to increasing NGR occurs near the 69.9 m (Hole
U1354A) and 64.75 m (Hole U1354B) locations of
the Brunhes/Matuyama boundary and also coincides
with a marked reduction in the abundance and diversity of nannofossil assemblages (see “Biostratigraphy”).
The larger scale sinusoidal NGR pattern is modulated
by the same shorter, cyclic changes in NGR documented for the upper portions of Sites U1351–
U1353. Many of these changes probably reflect lithologic changes related to sea level variations at
100 k.y. (back to 0.6 Ma) and 40 k.y. (earlier) Milankovitch cyclicity. Above the Brunhes/Matuyama
boundary, the NGR record (and also the magnetic
susceptibility record) reflects two major cycles that
probably correspond to marine isotope Stages (MIS)
1–7, with significant sand units at 22–32 and 56–
61 m that can be correlated tentatively with MIS Interglacials 5 and 7, respectively. Below the Brunhes/
Matuyama boundary, probable 40 k.y. Milankovitchscale variations in NGR and lithology continue, but
no specific correlation can yet be made with the established oxygen isotope record.
P-wave velocities
P-wave velocities were recorded continuously in
Holes U1354A–U1354C at 2.5 cm intervals using the
PWL. The PWC and PWB were used to measure Pwave velocity in Holes U1354B and U1354C (Fig.
F22B). P-wave measurements yielded good results in
the uppermost 217.5 m. Comparably good results
were observed only in cores from Site U1353. At
both sites, the long records are a result of the absence
of the sediment cracking caused by high gas content
at Sites U1351 and U1352. With this data set, an excellent positive correlation was found between PWL
estimates from both holes, and a good correlation
13
Expedition 317 Scientists
was found between PWL, PWC, and PWB estimates
in Holes U1354B and U1354C. Nevertheless, PWB Pwave velocities are generally slightly lower than velocities measured with the PWL and PWC.
P-wave velocities show little vertical trend and average ~1500–1600 m/s. One major step was observed
at 20–21 m in Hole U1354A and at 19–20 m in Hole
U1354B. An offset between ~68 and 70 m in Hole
U1354A and between 64 and 65 m in Hole U1354B
marks a hiatus that was also observed in magnetic
susceptibility.
Spectrophotometry and colorimetry
Spectrophotometric measurements and associated
colorimetric calculations were made on section
halves at 5 cm intervals at the same positions as MSP
measurements. Color data were recorded as L*, a*,
and b* variations. Several pronounced changes in
color occur at Site U1354, and these are particularly
well expressed in the upper part of the site, where
core recovery was greatest (Fig. F23). Decreases in L*
are typically coeval with decreases in b* and increases in a*, a pattern also noted at Site U1353. An
example occurs in the interval between 20 and 26 m
in Hole U1354B (all sections of Core 7H). This shift
between 20 and 26 m is associated with a decrease in
both NGR and magnetic susceptibility (Fig. F23).
Lithologically, this interval is associated with a sandy
horizon. A sharp excursion to higher b* values occurs at ~50 m in Hole U1354B, which is also coeval
with a decrease in NGR and magnetic susceptibility.
A less pronounced and more protracted increase in
L* values is associated with this shift, as well as a
shift to lower a* values. (Fig. F23). This excursion is
associated with a marl interval (see “Lithostratigraphy”). The fact that both of these intervals are associated with low NGR and magnetic susceptibility values highlights the utility of using color
measurements to help distinguish between the
causes of changes in NGR and magnetic susceptibility.
Site U1354
performed in this manner and that catwalk samples
are not required.
In the uppermost 10 m of Hole U1354B, porosity
and void ratio decrease and bulk density increases.
There is little change in the following 100 m, below
which porosity decreases again (Fig. F25). These observations are consistent with the porosity trends
seen at the other three sites. Grain density shows
some scatter near the surface, reflecting the variable
lithology in Hole U1354B (see “Lithostratigraphy”).
These grain densities in the top of Hole U1354B are
more variable than those at Sites U1352 and U1353
but are less variable than those at Site U1351, suggesting decreasing variability with distance from the
shore.
Sediment strength
Sediment strength measurements were conducted on
working section halves from Holes U1354B and
U1354C using automated vane shear (AVS) and fall
cone penetrometer (FCP) testing systems (Fig. F26).
A comparison of both measurement methods is
shown in the cross-plot in Figure F26C. Shear
strength indicates that sediments range from very
soft (0–20 kN/m2) to very stiff (150–300 kN/m2).
Vane shear and fall cone shear strength correlate well
in very soft and soft sediments, but AVS values are
about three times lower in firm to very stiff sediments (standard deviation = 22.8 kPa) than FCP values (standard deviation = 86.0 kN/m2). A similar pattern was observed at all other Expedition 317 sites.
These findings suggest that the applicability of vane
shear in firm to very stiff sediments is limited and
that the vane shear test underestimates the strength
of stiffer sediments. Overall, vane shear and fall cone
strength data from Hole U1354B are positively correlated (Fig. F26). Between 0 and ~250 m, shear
strength generally increases, indicating a change
from very soft to firm sediments. The lower sediment
strength below ~250 m was also observed in cores
from Hole U1353C and might coincide with XCB
drilling.
Moisture and density
MAD sampling of cores on the catwalk, followed by
adjacent sampling on the sample table, was carried
out in cores from Holes U1354B and U1354C (Cores
1X through 15X). MAD samples were taken prior to
discrete P-wave analysis. This approach effectively
removed any bias toward more water being in the
sample table samples: there was excellent correlation
between catwalk and sample table MAD results (Fig.
F24). We recommend that future MAD sampling be
Proc. IODP | Volume 317
Geochemistry and microbiology
Organic geochemistry
Shipboard organic geochemical studies of cores from
Holes U1354A–U1354C included monitoring hydrocarbon gases, carbonate carbon, total carbon (TC),
organic carbon, and total nitrogen (TN). The procedures used in these studies are summarized in “Geochemistry and microbiology” in the “Methods”
14
Expedition 317 Scientists
chapter. All depths in this section are reported in
m CSF-A.
Site U1354
TOCDIFF/TN generally decreases with depth, with the
exception of the high-carbonate samples in the 73–
76 m depth interval (Fig. F28E).
Volatile gases
All cores recovered from Holes U1354A and U1354C
were monitored for the presence of gaseous hydrocarbons using the headspace (HS) gas technique (Table T15). In Hole U1354A, only background
amounts (1–3 ppmv) of hydrocarbons were detected,
with the exception of the 33–75 m depth interval,
where headspace methane increases to a peak of 23
ppmv at 46 m and then decreases to background levels below 75 m (Fig. F27). HS samples from sediments with slightly elevated methane also contain
trace amounts (0.7–1.3 ppmv) of ethane (Fig. F27).
Small amounts of gas were recovered from air enclosed in the core liner of Cores 317-U1354A-14H
and 317-U1354B-14H (Table T16). These samples
were reported as core void gas (VAC) samples, but
were not from an actual gas void within the core.
These samples contain methane (3.0–4.8 ppmv)
slightly above background levels; no ethane was detectable.
HS samples from Hole U1354C also contain only
background levels of methane to ~200 m, where
methane concentrations begin to increase, eventually leveling off in the range of 12,000–22,000 ppmv
to the deepest sample in Hole U1354C at 375 m. All
samples from Hole U1354C with elevated methane
concentrations also contain 2–29 ppmv ethane. CO1
is present in HS samples below 250 m at concentrations significantly above atmospheric levels (Fig.
F27). C3+ hydrocarbons were not detected in samples
from Site U1354.
Carbon and elemental analyses
The results of inorganic carbon (IC), carbonate, TC,
total organic carbon by difference (TOCDIFF), TN, and
TOCDIFF/TN analyses on selected sediment samples
from Site U1354 are given in Table T17. Only 18 sediment samples were analyzed because of time constraints at the end of the expedition. TC, TN, TOCDIFF,
and calcium carbonate contents are plotted against
burial depth in Figure F28. Calcium carbonate contents range from 1.3 to 52 wt% in sediments analyzed to burial depths of 81 m (Fig. F28A). TC (as at
Site U1353) has a profile remarkably similar to that
of carbonate content, with no trend but with the
highest values (>5 wt%) clustered in the 73–76 m
depth range. TN amounts are very low and range
from 0.004 to 0.08 wt%, having no apparent trend
with depth (Fig. F28C).
Organic carbon ranges from 0.02 to 1.1 wt% (Fig.
F28D), with the highest value at 50 m. The ratio of
Proc. IODP | Volume 317
Inorganic geochemistry
A total of 69 interstitial water samples (Tables T18,
T19) were collected and analyzed at Site U1354. Hole
U1354A, which was dedicated mainly to wholeround sampling for geochemistry, was sampled at an
average frequency of one sample per 1.7 m down to
84 m. Hole U1354C was sampled less frequently (one
sample per core, where recovery allowed) from 82 to
319 m. Interstitial water chemistry is plotted versus
depth in Figures F29–F34.
Salinity, chloride, sodium, and pH
Salinities in samples near the seafloor are about normal seawater values of 3.4 and decline to 3.3 over
the 17–38 m depth interval (Fig. F29A). From 38 to
150 m, salinity gradually increases to slightly above
seawater (3.6) and then fluctuates to lower values at
~210 m before climbing to 3.8 in the bottom three
samples. Chloride (Fig. F29B) and sodium (Fig.
F29C) do not parallel salinity measurements, but
both increase to ~15% above seawater values over
the 0–84 m depth interval. From 84 to 240 m, chloride and sodium values scatter between 580 and 640
mM and 520 and 560 mM, respectively, and do not
significantly vary with depth. Sodium and chloride
increase significantly in the bottom two samples in
parallel with the increase in salinity (Fig. F29). Measured pH values scatter between 7.1 and 7.8, with no
consistent depth trend (Fig. F29D).
Calcium, magnesium, and strontium
Calcium and magnesium both decrease below a 0–
3.7 m chemically homogeneous zone to minima of
5.7 mM at 22 m for calcium and 30.7 mM at 54 m
for magnesium (Fig. F30A–F30B). Calcium then increases to 13.1 mM and magnesium increases to 41.1
mM at 178 m. Between 178 m and the next sampled
depth at 205 m, a major discontinuity in the calcium
concentration profile is evident, with calcium decreasing by 34% to 8.6 mM and then rising gradually
to 15.6 mM in the deepest sample at 318 m. Magnesium also decreases in the same depth interval, but
not as dramatically. The Mg/Ca ratio increases from
5.1 in near-surface sediments to 6.3 at the depth of
the calcium minimum, decreases to 3.1 at 178 m, increases to 4.3 at 215 m, and then drops gradually to
2.4 at 318 m (Fig. F30C).
Strontium rapidly increases between 5.1 and 17.6 m
from seawater values to a maximum of 440 µM before gradually increasing toward 600 µM at ~60 m
15
Expedition 317 Scientists
(Fig. F30D). Thereafter, strontium concentrations
vary between 518 and 622 µM. The Sr/Ca ratio increases rapidly from seawater values in near-surface
sediments to a maximum of ~0.075 at 34–41 m before gradually decreasing again to ~0.046 at 178 m
(Fig. F30E). The Sr/Ca ratio increases to 0.067 in the
calcium minimum zone, before decreasing to 0.034
in the deepest sample.
Alkalinity, sulfate, and phosphate
Alkalinity is relatively constant over a near-surface
(0–3.7 m) chemically homogeneous zone and then
increases somewhat steeply from 3.1 mM at 3.7 m to
8.8 mM at 12.2 m. Alkalinity fluctuates between 8.7
and 10.3 mM to 50 m (Fig. F30F) and then slowly decreases to ~2.2 mM at 318 m, with the exception of
samples from Sections 317-U1354C-18X-2 (205.20
m) and 19X-2 (214.70 m), which show elevated alkalinities of 3.8 and 4.2 mM, respectively. Sulfate decreases rapidly beneath the chemically homogeneous zone from 28 mM at 3.7 m to zero at 34.2 m.
Sulfate remains at or near zero to ~59 m and then
gradually increases to 16.4 mM at 178 m (Fig. F31A).
Sulfate returns to zero by the next sampled depth at
205 m, which corresponds with the depth of the second increases in methane and alkalinity.
Phosphate increases from 4.7 µM at 1.3 m to 13.8
µM at 9.7 m, remains high to 21 m, and then decreases steadily to 1.4 µM at 79 m (Fig. F31B). Deeper
samples have phosphate concentrations <1.5 µM
and a generally uniform trend, except that samples
at 205.2 and 214.7 m have slightly higher phosphate
than adjacent samples.
Potassium, barium, lithium, silicon, boron, iron,
and manganese
Potassium decreases steadily from ~11 mM, slightly
above seawater values, to 2.9 mM at 235 m, with a
slight perturbation in the samples at 165 and 178 m
(Fig. F32A). Potassium then rises again to 4.7 mM at
318 m. Barium rapidly increases to 2.5 µM at 23.6 m
and then varies at ~2.3 µM between 23.6 and 57.6 m
(Fig. F32B). Barium increases to 3.0 µM at 67.8 m
and then decreases to 1.2 µM at 111 m, with a spike
to 2.6 µM at 97 m. Thereafter, barium remains constant before increasing below 150 m to a maximum
of 7.9 µM in the deepest sample at 318 m, and with a
spike to 3 µM at 165 m.
Lithium initially increases from seawater values in
the shallowest sample to 41.1 µM at 19.2 m and then
remains relatively constant to 32.6 m (Fig. F32C). Below 32.6 m, lithium begins to decrease from 41.8 µM
to a minimum of 19.9 µM at 104 m. It then increases
with depth, with a perturbation in the trend beProc. IODP | Volume 317
Site U1354
tween 160 and 200 m. The deepest sample contains
the maximum concentration of 86.6 µM.
Silicon concentrations increase from 188 to 595 µM
in the uppermost 12 m and then decrease to
~400 µM (Fig. F32D). From 17.6 to 100 m, silicon
mainly varies between 350 and 550 µM, with some
concentration peaks as high as 664 µM (Fig. F32D).
From 100 to 165 m, silicon gradually decreases to
221 µM and then remains nearly constant to the
deepest sample.
Boron concentrations are at seawater values of
~0.4 mM in the shallowest samples and gradually increase in a fairly even fashion to 1.26 mM in the
deepest sample (Fig. F33A).
Both iron and manganese concentrations are largely
scattered between 9 and 22 µM and 3 and 9 µM, respectively (Fig. F33B–F33C). Iron and manganese
tightly co-vary throughout the cored interval at Site
U1354. Iron has a significantly high concentration
of 27.6 µM at 56.2 m, which is not mirrored by the
manganese profile (Fig. F33B–F33C). Below 85 m,
both iron and manganese have relatively constant
values, except that manganese is elevated relative to
iron in the three deepest samples (Fig. F33B–F33C).
Preliminary interpretation of diagenesis
Interstitial water geochemistry in the uppermost
80 m at Site U1354 is dominated by a zone of complete sulfate depletion from 34 to 60 m (Figs. F34,
F35). The boundaries of this zone are characterized
by inflections in the magnetic susceptibility data (see
Fig. F19). Where sulfate is zero, methane begins to
build up. It then decreases to near background concentrations at 60 m, the depth at which sulfate reappears in the cores. The apparent carbon–sulfur stoichiometry of sulfate reduction is significantly
different above and below the zone of sulfate depletion (Fig. F35). In the 0–34 m depth interval above
the region of zero sulfate, the ratio of [alkalinity
added plus cations (Ca2+ and Mg2+) removed] to sulfate removed is 1.3:1, consistent with sulfate reduction being fueled by about one-third organic matter
oxidation and two-thirds anaerobic methane oxidation. In the 60–178 m depth interval, the same ratio
is 0.98:1, indicating that sulfate reduction is driven
almost exclusively by anaerobic methane oxidation
(Fig. F35). The very low phosphate throughout the
deeper zone and the somewhat higher phosphate in
the shallower sulfate reduction zone is consistent
with small quantities of phosphate being generated
by organic-matter oxidation in the 0–34 m depth interval. The methane oxidation occurring in the
deeper sulfate reduction zone generates no phosphate ions. However, below 84 m in Hole U1354C,
the slopes of the sulfate, alkalinity, calcium, and
16
Expedition 317 Scientists
magnesium depth profiles all change slightly, and
the exact relationship developed in Hole U1354A
may not apply for the deeper interval in Hole
U1354C.
A hiatus is present at ~75 m, marked by a change in
sedimentation rate from 210 m/m.y. above to 93
m/m.y. below, which is followed by a further decrease to 45 m/m.y. below another hiatus at ~128–
190 m. Below 190 m, the sedimentation rate increases dramatically to 400 m/m.y. to the bottom
of the hole (see Fig. F29 in the “Expedition 317
summary” chapter). The change in sedimentation
rate below 190 m is coincidental with the second
appearance of methane at Site U1354 at 200 m. Apparently, sediments within the 74–190 m depth interval were deposited at a rate slow enough to permit continuous replenishment of dissolved sulfate
by diffusion from overlying seawater, thereby preventing methanogenesis. A review of methane occurrence at Deep Sea Drilling Project (DSDP)/ODP/
IODP sites indicates that ~40–50 m/m.y. is the minimum sedimentation rate required for sulfate depletion and methanogenesis to occur.
One notable aspect of the shallow pore water chemistry profiles at Site U1354 is the lack of a low-salinity zone like that seen at ~50 m at the more nearshore Site U1353. This may help clarify the origin of
this low-salinity zone. The water depth at Site U1353
is 85 m, compared with 110 m at Site U1354. Global
sea level was ~125 m below today’s sea level at the
Last Glacial Maximum ~20,000 years ago (Fairbanks,
1989), so both site locations may have experienced
periods of complete emergence. Therefore, the lack
of less saline water at Site U1354 and the presence of
less saline water at Site U1353 is more likely explained by the modern intrusion of meteoric water
from land than by the historic remains of freshwater
emplaced when the shelf was emergent.
Other changes in interstitial water chemistry at Site
U1354 are possibly related to carbonate diagenesis
and contributions from deeper basinal brines. The
main decreases in dissolved calcium and magnesium
occur within the depth intervals characterized by
sulfate reduction, methanogenesis, and anaerobic
methane oxidation. These processes are commonly
associated with precipitation of authigenic carbonates with distinct carbon isotopic compositions. The
increases in sodium and chloride from 0 to 60 m,
which are possibly related to an influx of saline fluid,
may also account for some of the other changes seen
at Site U1354, such as increases in barium, lithium,
and boron with depth.
Alternative sources of lithium could relate to ion-exchange or desorption reactions on authigenic clays
Proc. IODP | Volume 317
Site U1354
and the transformation of biogenic opal to opal-A.
The increase in lithium does not correspond to the
increase in silica. This relationship was also observed
at the other sites and may suggest a rather subtle influence of biogenic opal and that the major source of
lithium is the diagenesis of lithium-rich clay minerals. The boron increase with depth may also be related to the diagenetic opal transition and microbial
degradation of organic matter. The rapid barium increase in the sulfate reduction zone may reflect barite dissolution that resulted from enhanced barite
solubility.
Microbiology
No microbiological experiments were carried out
and no microbiological samples were recovered at
Site U1354.
Heat flow
Geothermal gradient
Two temperature measurements were made using
the SET tool in Cores 317-U1354C-14X and 16X. The
results of these measurements were poor because the
conductive cooling time after sediment penetration
was too short (Table T20; Fig. F36), possibly as a result of tool movement within the sediment because
of ship heave and/or penetration of loose, caved sediments at the bottom of the hole. Accordingly, it was
not possible to determine geothermal gradient and
heat flow.
Thermal conductivity
Thermal conductivity was measured in whole-round
core sections from Holes U1354A–U1354C using the
full-space needle probe method. Cores retrieved
from broken liners were not measured. Measurement
frequency was usually more than once per core
(specifically, once every two sections above 50 m
CSF-A; unless otherwise noted, all depths in this
section are reported in m CSF-A) and once every
section below 50 m, with five measuring cycles at
each point. This includes 35 points in Hole U1354A
(0.7–84.8 m), 25 points in Hole U1354B (0.7–75.9
m), and 43 points in Hole U1354C (67.2–374.8 m)
(Table T21). The middle of each section was chosen
as the measurement point unless a void or crack was
observed (see “Heat flow” in the “Methods”
chapter). Probe V10701 was used, and heating power
was kept to ~3 W for the full-space method.
After quality control (see “Heat flow” in the “Methods” chapter), good results were obtained for 17
points in Hole U1354A, 14 points in Hole U1354B,
17
Expedition 317 Scientists
and 23 points in Hole U1354C, covering depth intervals of 0.7–82.6, 3.2–75.9, and 70.2–336.6 m, respectively (Table T21). Although the number of measuring cycles was increased to five based on experience
gained from Site U1352, many measurements were
still discarded because of poor contact caused by
loose sediments.
Thermal conductivity measurements at Site U1354
range from 1.183 to 1.873 W/(m·K) (average = 1.409
W/[m·K]) (Table T21). These values are slightly
higher than those from slope Site U1352 for the
equivalent depth interval (to ~375 m). For the uppermost 130 m, thermal conductivity values are
also higher at Site U1354 than in the same interval
at nearby ODP Site 1119 (Shipboard Scientific Party,
1999). The high conductivities at Site U1354 may
be due to high concentrations of quartz (6.5–12.5
W/[m·K]) in fine-grained sediment, including the
clay-sized fraction (see “Lithostratigraphy”), and/
or carbonate cementation (0.5–4.4 W/[m·K]).
Thermal conductivity versus depth data from Holes
U1354A and U1354B are consistent (Fig. F37A). In
addition, results from Hole U1354C could be
projected to those from the upper portions of Holes
U1354A and U1354B. Thermal conductivity seems to
be constant (or very subtly increasing) with depth,
except for peaks at 22–30 m. A similarly constant
profile was observed at slope Site U1352. Peaks of
>1.700 W/(m·K) come from very fine to fine sand
layers, which do not occur in intervals with low porosity or high bulk density. However, thermal conductivity in general correlates negatively with porosity and positively with bulk density, as expected (Fig.
F37B–F37C). This may indicate that the sand layers
yielding high thermal conductivity values consist
mainly of high thermal conductivity material such
as quartz. There is no distinguishable correlation between thermal conductivity and lithology at this
site.
Downhole logging
Operations
Preparations for downhole logging of Hole U1354C
began after APC/XCB coring to a total depth of 384.2
m DSF (~509 m DRF) was completed at 1800 h on 1
January 2010 (all times are ship local time, UTC +
13 h). In preparation for logging operations, the hole
was swept and circulated with 50 bbl of high-viscosity mud and displaced with 320 bbl of heavy mud
(~10.5 ppg). The bit was raised to the logging depth
of 231 m DRF (106 m DSF). Because of the potential
for unstable hole conditions, our previous experience logging shelf Sites U1351 and U1353, and time
Proc. IODP | Volume 317
Site U1354
constraints at the end of the expedition, logging was
limited to a single tool run without radioactive
sources. A modified tool string (“sonic combo”),
which consisted of the HNGS, the DSI, the General
Purpose Inclinometry Tool (GPIT), and the DIT, was
rigged up by 0135 h on 2 January and run into the
hole (RIH) at a speed of 2000 ft/h. While the tool
string was being lowered, data were recorded from
the seafloor to the total depth of 505 m WRF. The
first logging pass was started at total depth at 0245 h
at a speed of 900 ft/h and stopped at 440 m WRF, at
which point the tool string was again RIH to total
depth for a full pass. The main pass began at 0308 h
from total depth at a speed of 900 ft/h and was completed at 0500 h when the seafloor was identified in
the gamma ray log at 122 m WRF. The tool string
was brought back to the surface and rigged down
completely by 0607 h. By 0625 h, the rig floor was
clear of all logging equipment and ready for the cementing protocol in Hole U1354C that concluded
drilling operations for Expedition 317.
Data quality
Figures F38, F39, and F40 summarize the main logging data recorded in Hole U1354C. These data were
converted from original field records to depth below
seafloor and processed to match depths between different logging runs. The resulting depth scale is wireline log matched depth below seafloor (WMSF; see
“Downhole logging” in the “Methods” chapter).
Because the DSI requires borehole centralization to
properly measure sonic velocities in the formation,
an eccentralizing caliper was not included in the tool
string so that the quality of the acoustic logs and the
smooth motion of the tool string would not be adversely affected. Without a caliper, the first indicator
of the quality of the data is the correlation between
the different measurements. If any lows in the
gamma ray log were due to hole enlargement, the resistivity and velocity logs should also display lower
values or remain unchanged because they are least
affected by borehole irregularities. Instead, the significant increases in resistivity and velocity associated with the gamma ray excursions (Figs. F38, F39)
show that these intervals are likely consolidated
sand-rich layers and that the change in gamma ray is
representative of true changes in lithology. A comparison with the logs recorded at the other shelf sites
(U1351 and U1353) also shows that the trends and
changes in the gamma ray logs can be visually correlated across the shelf (see Fig. F25 in the “Expedition
317 summary” chapter), indicating the good quality
of the logs recorded in Hole U1354C. Such correlations between sites will be fully characterized postcruise.
18
Expedition 317 Scientists
The gamma ray logs agree reasonably well with the
NGR track data measured on cores from Hole
U1354C (Fig. F38), validating the overall gamma ray
log trend. However, poor core recovery in intervals
with significant gamma ray variability, particularly
in the sand-rich intervals, makes it difficult to precisely match log and core measurements.
The quality of some of the logging data sets can also
be evaluated by internal consistency. The agreement
between the deep- and medium-penetration resistivity curves is an indication that the borehole was not
anomalously large or irregular (Fig. F38). The clear
arrivals in acoustic logging waveforms and the high
coherence indicated by distinct red areas in the VP
and VS tracks in Figure F39 show that the DSI was
able to measure reliable VP and VS values. Additional
postcruise processing will refine these profiles and
characterize some of the high-coherence events that
were not labeled automatically at the time of acquisition. Finally, the comparison in Figure F41 between
the data recorded during the downlog and the uplog
shows that all measurements repeat very well between the two passes. The notable discrepancies in
the VP and VS logs are related to the failure of the automatic processing to identify the correct arrivals
and will likely be reduced by postcruise processing. A
depth offset in the resistivity curves between ~150
and 130 m WMSF is the result of variations in wireline tension and cable stretch when the top of the
tool string entered the drill pipe.
Porosity and density estimation
from the resistivity log
In order to provide a measure of porosity and density
from the logs without nuclear sources, we used Archie’s (1942) relationship to calculate porosity from
the phasor deep induction log (IDPH), which is the
log least affected by borehole conditions (Schlumberger, 1989) and combined it with MAD grain density data to derive a density profile. Archie (1942) established an empirical relationship between porosity
(φ), formation resistivity (R), and pore water resistivity (Rw) in sandy formations:
φ = (aRw/R)1/m,
where m and a are two empirical parameters often
called cementation and tortuosity (or Archie) coefficients, respectively. The resistivity of seawater (Rw)
was calculated as a function of temperature and salinity, as described by Fofonoff (1985). Pore water salinity was assumed to be 35.5 ppt (or 3.55%; see
“Geochemistry and microbiology”), and temperature was assumed to follow a local linear gradient of
40°C/km, as suggested by in situ measurements at
Proc. IODP | Volume 317
Site U1354
Site U1352 (see “Heat flow” in the “Site U1352”
chapter) and in the Clipper-1 well (Shell BP Todd,
1984). The most realistic value for the cementation
coefficient is a = 1 because this gives a resistivity
equal to formation water resistivity when porosity is
100%. A value of m = 1.9 was chosen iteratively to
provide the best baseline match with MAD porosity
data. Although Archie’s relationship was originally
defined for sand-rich formations, Jarrard et al. (1989)
showed that the effect of clay minerals is moderate,
and the relationship is commonly used to estimate
porosity in clay-rich formations with poor borehole
conditions (Collett, 1998; Jarrard et al., 1989). The
resulting porosity log is shown in Figure F38, where
it compares well with MAD porosity data. Using
MAD grain density, we used this resistivity-derived
porosity to calculate a new density curve, which is in
good agreement with core measurements (Fig. F38).
Logging stratigraphy
The combined analysis of gamma ray, resistivity, and
velocity logs can be used to identify logging units defined by characteristic trends. In addition, the proximity of Site U1354 to Site U1353 and the similarities
between the logs recorded at these two sites reflect
stratigraphic continuity across the shelf, allowing for
the definition of a common logging stratigraphy between the two sites. The two following logging units
were identified in Hole U1354C.
Logging Unit 1 (110–285 m WMSF), similar to logging Unit 1 in Hole U1353C, is characterized by an
increasing trend in gamma ray from the top of the
unit to ~185 m WMSF, followed by a generally decreasing trend to the base of the unit. These trends
are interrupted by intervals of low gamma ray and
high resistivity and velocity that are interpreted as
sandy intervals, most of which coincide with intervals of low core recovery and the occurrence of sand
in the recovered material. In Figure F39, the two
most prominent intervals with very high velocity
values (185–195 and 220–230 m WMSF) have the
same character as two analogous intervals in Hole
U1353C (178–185 and 202–208 m WMSF; see
“Downhole logging” in the “Site U1353” chapter)
and coincide with two seismic unconformities across
these two sites (see “Log-seismic correlation”).
Logging Unit 2 (285–384 m WMSF) is characterized
by slightly decreasing trends with depth in gamma
ray and resistivity, with only limited variability, and
increasing velocity along a likely compacting trend
(Figs. F38, F39). As at Site U1353, this unit is also
characterized by very low core recovery associated
with the predominance of muddy sands and sandy
mud in the recovered intervals (see “Lithostratigraphy”).
19
Expedition 317 Scientists
Log-seismic correlation
A depth–traveltime relationship can be determined
from sonic logs and used to correlate features in the
logs, recorded in the depth domain, with features in
seismic stratigraphy, recorded in the time domain. A
synthetic seismogram was constructed for Hole
U1354C from the sonic log and the density curve
calculated from the resistivity log using Archie’s relationship. Figure F42 shows relatively good agreement between the synthetic waveform and reflections in the seismic line closest to Site U1354. High
variability in the logs in logging Unit 1 corresponds
to an interval of strong seismic reflections between
~0.27 and ~0.43 s two-way traveltime. In particular,
seismic sequence boundaries U10–U13, interpreted
from seismic data (see “Seismic stratigraphy” in the
“Expedition 317 summary” chapter), are well resolved in the synthetic seismogram and correspond
to distinct features in sonic, calculated density, and
gamma ray logs. U9 is somewhat deeper in the seismic section in logging Unit 2, where low variability
in the logs results in fewer distinctive waveforms in
the synthetic seismogram. U12, U11, and U10 all
have similar log characteristics, as at Site U1353, and
are located at abrupt transitions from high gamma
ray, lower density, and low velocity below to low
gamma ray, higher density, and very high velocity
above. Although core recovery through these highamplitude features is poor in Hole U1354C, at Site
U1353 these boundaries correspond to lithologic
changes from dominantly muddy sediments below
to sand-, shell-, and gravel-dominated sediments
above (see “Lithostratigraphy” in the “Site U1353”
chapter). As at Site U1353, U13 is less prominent in
both the synthetic seismogram and the seismic stratigraphy than the deeper boundaries, but at Site
U1354 it has the same polarity as U10–U12. The difference in polarity between sites could indicate a
change in the character of the boundary itself but
may also simply be the result of trying to resolve a
surface that is thinner than the resolution of the seismic data. Additional postcruise research will refine
these correlations by reprocessing the sonic logs and
providing more detailed synthesis of core-log correlations at this site.
Stratigraphic correlation
Holes U1354A, U1354B, and U1354C were drilled
~20 m from each other, with Hole U1354A being
dedicated to whole-round sampling for geochemical
analyses. The drilling of three holes at Site U1354
provides an opportunity for stratigraphic correlation
and possible construction of a spliced stratigraphic
Proc. IODP | Volume 317
Site U1354
record with a common core composite depth below
seafloor (CCSF) depth scale (see “Stratigraphic correlation” in the “Methods” chapter). Magnetic susceptibility (MSL) and NGR data were used to facilitate the correlation of cores at Site U1354. L*
reflectance values and GRA bulk density measurements were also used to cross-check the validity of
depth adjustments. A number of key features in the
analyzed data are shared by all holes, allowing correlative ties to be made (Fig. F43). The depths of
these features (expressed in m CSF-A) are often different between the holes and require depth shifts of
individual and/or multiple cores by as much as
2.18 m. This demonstrates that the stratigraphic record for all holes is characterized by localized differences in sedimentation history, as was also found at
Sites U1352 and U1353. Because Site U1354 was
drilled on the continental shelf, this observation fits
with the interpretation that the sedimentation and/
or postsedimentation history of this environment
was extremely dynamic.
The correlation presented here suggests that Hole
U1354B is incomplete relative to Hole U1354A, and
depth shifts of cores from Hole U1354B are hence
necessary to align tie points between each hole. The
correlated holes with depth shifts are plotted in Figure F43, and depth adjustments made to cores are
provided in Table T22. A key correlative feature of
Holes U1354A and U1354B is the geomagnetic polarity reversal interpreted to include the Brunhes/Matuyama boundary, which occurs at ~71.3 m CCSF (see
“Paleomagnetism”). This reversal and its associated
lithologic boundary have a distinctive expression in
the NGR and MSL data, allowing the event to be unambiguously correlated between the two holes (Fig.
F43). Cores from Hole U1354C are below the depth
of the Brunhes/Matuyama boundary based on the
correlation presented here, and this inference is supported by paleomagnetic polarity data. Below the
paleomagnetic reversal, correlation between Holes
U1354A, U1354B, and U1354C is complicated by artifacts in the physical property records arising from
drilling disturbance such as shell-hash cave-in. Care,
therefore, was taken that these artifacts were not
used in correlation. One tie point at 82 m CCSF was
identified in Holes U1354B and U1354C after these
artifacts were taken into account.
The presence of drilling disturbance in all holes hindered the creation of a spliced composite record for
Site U1354 that includes only the parts of each hole
deemed to be best representative of a given depth interval. Indeed, the exclusion of clear artifacts from a
spliced record could not be avoided, and only limited increased stratigraphic coverage can be gained
by splicing. Furthermore, the fact that Hole U1354B
20
Expedition 317 Scientists
Site U1354
is likely incomplete relative to Hole U1354A is problematic for creating a spliced record because the record of Hole U1354A is itself incomplete because of
extensive whole-round sampling.
Jarrard, R.D., Dadey, K.A., and Busch, W.H., 1989. Velocity
and density of sediments of Eirik Ridge, Labrador Sea:
control by porosity and mineralogy. In Srivastava, S.P.,
Arthur, M.A., Clement, B., et al., Proc. ODP, Sci. Results,
105: College Station, TX (Ocean Drilling Program), 811–
835. doi:10.2973/odp.proc.sr.105.146.1989
References
Kameo, K., and Bralower, T.J., 2000. Neogene calcareous
nannofossil biostratigraphy of Sites 998, 999, and 1000,
Caribbean Sea. In Leckie, R.M., Sigurdsson, H., Acton,
G.D., and Draper, G. (Eds.), Proc. ODP, Sci. Results, 165:
College Station, TX (Ocean Drilling Program), 3–17.
doi:10.2973/odp.proc.sr.165.012.2000
Archie, G.E., 1942. The electrical resistivity log as an aid in
determining some reservoir characteristics. J. Pet. Technol., 5:1–8.
Browne, G.H., and Naish, T.R., 2003. Facies development
and sequence architecture of a late Quaternary fluvialmarine transition, Canterbury Plains and shelf, New
Zealand: implications for forced regressive deposits. Sediment. Geol., 158(1–2):57–86. doi:10.1016/S00370738(02)00258-0
Collett, T.S., 1998. Well log evaluation of gas hydrate saturations. Trans. SPWLA Annu. Logging Symp., 39:1998MM.
Fairbanks, R.G., 1989. A 17,000-year glacio-eustatic sea
level record: influence of glacial melting rates on the
Younger Dryas event and deep-ocean circulation. Nature
(London, U. K.), 342(6250):637–642. doi:10.1038/
342637a0
Fofonoff, N.P., 1985. Physical properties of seawater: a new
salinity scale and equation of state for seawater. J. Geophys. Res., [Oceans], 90(C2):3332–3342. doi:10.1029/
JC090iC02p03332
Hayward, B.W., 2001. Global deep-sea extinctions during
the Pleistocene ice ages. Geology, 29(7):599–602.
doi:10.1130/00917613(2001)029<0599:GDSEDT>2.0.CO;2
Hornibrook, N. de B., Brazier, R.C., and Strong, C.P., 1989.
Manual of New Zealand Permian to Pleistocene foraminiferal biostratigraphy. Paleontol. Bull., 56.
Proc. IODP | Volume 317
Lu, H., and Fulthorpe, C.S., 2004. Controls on sequence
stratigraphy of a middle Miocene–Holocene, currentswept, passive margin: offshore Canterbury Basin, New
Zealand. Geol. Soc. Am. Bull., 116(11):1345–1366.
doi:10.1130/B2525401.1
Schlumberger, 1989. Log Interpretation Principles/Applications: Houston (Schlumberger Educ. Serv.), SMP–7017.
Shell BP Todd, 1984. Drilling completion report, Clipper-1.
Offshore Canterbury, South Island, New Zealand.
PPL38202. Min. Econ. Dev. N. Z. Pet. Rep., PR1036.
https://data.crownminerals.govt.nz/MEDGUEST/
system/mainframe.asp
Shipboard Scientific Party, 1999. Site 1119: drift accretion
on Canterbury Slope. In Carter, R.M., McCave, I.N.,
Richter, C., Carter, L., et al., Proc. ODP, Init. Repts., 181:
College Station, TX (Ocean Drilling Program), 1–112.
doi:10.2973/odp.proc.ir.181.103.2000
Publication: 4 January 2011
MS 317-106
21
B
CDP
NW
0
0.25
5600
5400
Profile 66
SPHDIV display (gain 180)
5200
5000
SW
0
Site U1354
18 19
17
15 16 14
13
12
11
10
0.50
9
8
Two-way traveltime (s)
CDP
SE
4800
7
0.75
6
1.00
0.25
Two-way traveltime (s)
A
2200
2400
2600
2800
3000
NE
Profile 07a
SPHDIV display (gain 180) Site U1354
18 19
17
15 16 14
13
1112
10
Expedition 317 Scientists
Proc. IODP | Volume 317
Figure F1. A. Dip Profile EW00-01-66 showing Site U1354. B. Crossing strike Profile EW00-01-07A. Red = actual penetration, yellow = proposed
penetration. CDP = common depth point. MP = Marshall Paraconformity.
9
0.50
8
7
0.75
6
1.00
5
5
4
4
1.25
1.20
1 km
3
2
1.50
1.75
MP (“GREEN”)
2.00
1 km
Site U1354
22
Expedition 317 Scientists
Site U1354
Figure F2. Drilled and proposed Expedition 317 sites, together with EW00-01 high-resolution (frequencies up
to 300 Hz) MCS grid (thick straight lines), low-resolution CB-82 commercial MCS grid (thin straight lines), exploration wells Clipper and Resolution, and Ocean Drilling Program (ODP) Site 1119. The EW00-01 survey was
designed to provide improved vertical resolution (~5 m in the upper 1 s) to enhance our ability to define highfrequency sedimentary sequences. Also shown is the distribution of seismically resolvable sediment drifts D1–
D11, along with D8 and D9 subdrifts. Blue curved lines = crests of drift mounds, dashed blue lines = drifts identified on CB-82 profiles. Dip Profiles EW00-01-66, EW00-01-60, EW00-01-01, EW00-01-07a, and CB-82-25 are
also labeled.
44°
S
ta
ita
ng
Ra
Resolution
eo
D5
ra
D9
-1
Pa
r
D
D8 7
-1
D8-2
D83
D8
So
ut
h
Is
la
nd
N
0
40
0
D1
3
D9-
D11
CB-05B/D/E
D6
D1
D3
D4
D9
-2
0
20
CB-05C
600
CB-05F
Site U1353 (CB-01A)
CB-01B
0
80
0
0
1 0
ODP Site 1119
Site U1354 (CB-02A)
New Zealand
nd
CB-06B
la
2-
8
B-
Clipper
Is
25
60 66
45°
173°E
CB-04A
Site U1352 (CB-04B)
CB-04C
a
07
0
120
Site U1351 (CB-03B)
h
D2
Waita
ki
CB-01C
CB-02B
CB-03A
So
ut
01
C
0
20
45°
S
Canterbury Basin
km
171°E
172°
Drilled sites
Proc. IODP | Volume 317
173°
Proposed sites
23
Expedition 317 Scientists
Site U1354
Figure F3. Summary of core recovery, lithology, lithologic units, unit descriptions, physical property data, and
gamma ray data from downhole logging, Site U1354. NGR = natural gamma radiation. Downhole logging data
are plotted on the WMSF depth scale. A. Hole U1354B. (Continued on next page.)
Hole U1354B
A
Lith.
unit Age
1H
2H
3H
4H
5H
6H
7H
8H
9H
50
10H
11H
12H
13H
14H
15H
Proc. IODP | Volume 317
IA
Pleistocene-Holocene
Depth CSF-A (m)
0
Core
recovery Lithology
Clay
Silt
Very fine sand
Fine sand
Medium sand
Coarse sand
Very coarse sand
Granules
Pebbles
Cobbles
Grain size
b*
Unit description
-3
Magnetic
susceptibility
(instrument units)
7 -4
36
4
Gamma
ray
(gAPI)
NGR
(cps)
44
5
55
Subunit IA is characterized by its overall muddy
character, the dominant
lithology being a dark
greenish gray
homogeneous mud with a
few percent very fine
sand. Shells are either
rare and scattered or
locally concentrated in
layers up to 15 cm thick.
Bioturbation is common
and ranges between an
ichnofabric index of 1 and
4. Subordinate lithologies
include sandy mud, marl,
shell hash, muddy sand,
and very fine sand.
24
Expedition 317 Scientists
Site U1354
Figure F3 (continued). B. Hole U1354C.
Hole U1354C
B
0
Core
recovery Lithology
Clay
Silt
Very fine sand
Fine sand
Medium sand
Coarse sand
Very coarse sand
Granules
Pebbles
Cobbles
Grain size
Lith.
unit Age
1D
2H
3H
4X
5X
100
6X
7X
IA
8X
9X
Pleistocene-Holocene
50
Magnetic
susceptibility
(instrument units)
b*
Unit description
-9 -4
1
6
-4
16
36
8
NGR
(cps)
28
48 684
Gamma
ray
(gAPI)
24 44 64
Subunit IA is characterized by its overall muddy
character, the dominant
lithology being a dark
greenish gray
homogeneous mud with a
few percent very fine
sand. Shells are either
rare and scattered or
locally concentrated in
layers up to 15 cm thick.
Bioturbation is common
and ranges between an
ichnofabric index of 1 and
5. Subordinate lithologies
include sandy mud, marl,
shell hash, muddy sand,
and very fine sand.
10X
11X
150
12X
Subunit IB is dominated
by mud also, with rare to
common shells and
subordinate sandy mud,
muddy sand, sand, clay,
marl, and marlstone.
Subunits IA and IB are
differentiated on the
basis that Subunit IA
includes gray sands,
whereas Subunit IB does
not. In addition, Subunit
IB contains sandy marl
and sandy marlstone.
13X
Depth CSF-A (m)
14X
15X
16X
200
17X
IB
18X
19X
20X
Pliocene
21X
22X
250
23X
24X
25X
26X
27X
300
28X
29X
30X
31X
32X
350
33X
II
The dominant lithology of
Unit II consists of very
dark and dark greenish
gray and gray,
micaceous, very fine
sandy mud and mud,
typically with shells.
Both types of sediment
have variable degrees of
bioturbation ranging from
absent to heavy
(ichnofabric index of 1-4).
Muddy very fine sand
with shells occurs as a
minor lithology.
34X
35X
36X
400
Proc. IODP | Volume 317
25
Expedition 317 Scientists
Site U1354
Figure F4. Core recovery and lithology shown as a proportion of the recovered interval (lithology [%] × recovery [%]/100) in Hole U1354B. Depth scale in CSF-A (m) is variable, but for graphical purposes each core is
depicted by an equally thick horizontal bar.
Hole U1354B
Core
recovery (%)
0
50
Depth CSF-A (m)
0
20
40
Core
100
Weighted lithology (%)
0
10
20
30
40
50
60
70
80
90
100
1H
5H
10H
60
15H
Proc. IODP | Volume 317
Mud
Muddy sand
Shell hash
Very fine sand-fine sand
Marl
Sandy mud
26
Expedition 317 Scientists
Site U1354
Figure F5. Core recovery and lithology shown as a proportion of the recovered interval (lithology [%] × recovery [%]/100) in Hole U1354C. Depth scale in CSF-A (m) is variable, but for graphical purposes each core is
depicted by an equally thick horizontal bar.
Hole U1354C
Core
recovery (%)
0
50
80
Core
100
Weighted lithology (%)
0
10
20
30
40
50
60
70
80
90
100
2H
5X
Depth CSF-A (m)
100
140
180
220
260
10X
15X
20X
25X
300
30X
340
36X
Proc. IODP | Volume 317
Clay
Marl
Mud
Muddy sand
Shell hash
Very fine-fine sand
Medium coarse sand
Sandy mud
27
Expedition 317 Scientists
Site U1354
Figure F6. Tentative lithostratigraphic correlation between Holes U1354A and U1354B. Correlative lithostratigraphic horizons and surfaces are connected with gray lines. Geochemical and interstitial water sampling horizons are shown for Hole U1354A.
0
1H
5
Lithology
C
C
I
I
Core
Hole U1354B
Lithology
Core
Sampling
interval
Hole U1354A
0
1H
C
2H
5
I
2H
10
3H
15
I
C
I
10
I
I
S1
3H
4H
5H
15
C
6H
5H
I
C
I
I
S2
I
7H
25
7H
25
I
8H
30
Depth CSF-A (m)
20
6H
30
C
35
8H
I
35
I
C
I
I
40
9H
40
C
I
9H
45
I
C
I
10H
I
I
Depth CSF-A (m)
20
45
C
50
10H
50
I
I
C
I
I
55
11H
Mud
11H
55
C
I
Marl
C
60
I
12H
12H 60
I
C
I
65
C
S4
13H
I
70
13H
I
C
I
70
14H
I
I
75
14H
15H
C
C
18H
C
19H
I
I
Layer of gastropod
fragments
Drilling
disturbance
No recovery
Hole U1354A
Shipboard sampling
Geochemistry
C
75
Interstitial
I
water
Grain size
Clay
Silt
Very fine sand
Fine sand
Medium sand
Coarse sand
85
S5
17H
Bivalves
Coarse sand
Medium sand
Fine sand
Very fine sand
Silt
Clay
I
80
Shell
fragment
Gastropods
I
I
65
Sand
Grain size
Proc. IODP | Volume 317
28
Expedition 317 Scientists
Site U1354
Figure F7. Core photographs of a homogeneous mud lithology from Unit I. A. Homogeneous mud with a trace
amount of very fine sand (interval 317-U1354B-8H-3, 60–90 cm). B. Homogeneous mud with rare and scattered
shell fragments (interval 317-U1354A-2H-2, 1–31 cm). C. Homogeneous mud with abundant shells dominated
by the gastropod Stirocolpus (interval 317-U1354A-6H-1, 20–50 cm).
A
B
cm
C
cm
60
cm
20
5
65
25
10
70
30
15
75
35
20
80
40
25
85
45
30
90
Proc. IODP | Volume 317
50
29
Expedition 317 Scientists
Site U1354
Figure F8. Core photographs of additional Unit I lithologies. A. Very fine–fine micaceous sandy marl, possibly
representing the Holocene (interval 317-U1354A-1H-1, 0–30 cm). B. Marl with trace amount of very fine sand
(interval 317-U1354B-10H-6, 10–40 cm). C. Clay-rich homogeneous mud (interval 317-U1354A-12H-6, 55–85
cm). D. Clay-rich mud with intercalated normally graded sand laminations (interval 317-U1354C-14X-1, 5–35
cm).
A
B
C
cm
55
5
15
60
10
20
65
15
25
70
20
20
30
75
25
25
35
80
30
30
40
85
35
5
10
15
Proc. IODP | Volume 317
cm
D
cm
cm
10
30
Expedition 317 Scientists
Site U1354
Figure F9. Core photographs of coarser Unit I lithologies. A. Shell hash mixed with fine to medium sand (interval 317-U1354A-5H-1, 5–35 cm). B. Well-sorted, very fine to fine highly micaceous sand with millimeterlong broken shells (interval 317-U1354A-7H-4, 10–40 cm). C. Moderately sorted, very fine–medium very shelly
calcareous muddy sand (interval 317-U1354C-5X-1, 40–70 cm). D. Very fine calcareous sandy mud with large
clasts, including a bored calcareous nodule (interval 317-U1354B-12H-2, 60–95 cm).
A
B
C
D
cm
cm
cm
cm
5
10
40
60
10
15
45
65
15
20
50
20
25
70
75
55
25
30
80
60
30
35
85
65
35
40
90
70
Proc. IODP | Volume 317
31
Glauconite
(%)
CaCO3
(%)
0
0
40
80
0
10
20
Ferromagnesian
minerals
(%)
Mica
(%)
0
20
40
0
10
0
Quartz and
feldspar
(%)
Dense
minerals
(%)
10
20
0
40
Clay
(%)
80 0
40
Siliceous
bioclasts
(%)
Sand
(%)
80
0
40
80
0
4
Lith.
unit
8
Expedition 317 Scientists
Proc. IODP | Volume 317
Figure F10. Mineral and textural percentage estimations based on smear slide observations, Site U1354. CaCO3 estimates are plotted against data
from coulometry analyses for comparison.
50
IA
Depth CSF-A (m)
100
150
IB
200
250
300
II
350
Hole U1354A
Hole U1354B
Hole U1354C
Coulometry, Hole U1354B
Coulometry, Hole U1354C
Predicted depth of seismic sequence boundary
Subunit boundary
Unit boundary
Site U1354
32
Expedition 317 Scientists
Site U1354
Figure F11. Schematic of possible correlation of uppermost Holocene–Pleistocene succession between Holes
U1353B, U1354B, and U1351B. Columns are aligned relative to top depth and distance (not to scale). Distinct
lithologic boundaries and two predominant sand beds can be correlated among the columns. Four depositional
units are well defined: an uppermost unit of possible Holocene age and three units of possible upper Pleistocene
age. The two thick, well-sorted, very fine–fine sand beds at the most landward site (Hole U1353B) thin offshore.
Also, the upper sand bed disappears into a sandy interval in Holes U1354B and U1351B.
NW
SE
Land
Sea level
Offshore
Hole U1353B
Clay
Silt
Very fine sand
Fine sand
Medium sand
Coarse sand
Very coarse sand
(top; 84.7 mbsl)
Hole U1354B
(top; 113.4 mbsl)
Clay
Silt
Very fine sand
Fine sand
Medium sand
Coarse sand
Very coarse sand
Holocene ?
10
Hole U1351B
(top; 121.7 mbsl)
Clay
Silt
Very fine sand
Fine sand
Medium sand
Coarse sand
Very coarse sand
0
0
0
Holocene ?
?
10
20
Depth CSF-A (m)
?
20
30
10
20
?
30
40
30
40
50
40
50
60
50
60
~8 km
Well-sorted
very fine-fine sand
Shells/shell fragments
(bivalves/gastropods)
Burrows
Plant fragments
60
~5 km
Drilling disturbance
Proc. IODP | Volume 317
33
Expedition 317 Scientists
Site U1354
Figure F12. Core photographs of sediment correlation based on lithostratigraphy and paleomagnetic ages.
A. Interval 317-U1354A-13H-4, 0–45 cm. B. Interval 317-U1354B-13H-2, 47–102 cm. Both sections show a
sharp contact separating gray mud beneath from shelly sand above. The contact is at 69.6 m in Hole U1354A
and at 64.8 m in Hole U1354B. The sediment beneath the contact is heavily bioturbated. The shelly sand of
Section 317-U1354B-13H-2 contains a 7 cm long limestone clast above the contact. This contact and associated
sediments, named surface U1354B-S4 (see Table T3), are tentatively linked to seismic sequence boundary U16
(after Lu and Fulthorpe, 2004), which has a predicted depth of 64 m. Further correlation is provided by paleomagnetic ages, which locate the Brunhes/Matuyama boundary at 65–69 m in both cores.
A
B
cm
0
cm
50
5
55
10
60
65
15
70
U1354A-S4
20
75
25
80
30
U1354B-S4
85
90
35
95
40
100
Proc. IODP | Volume 317
34
Expedition 317 Scientists
Site U1354
Figure F13. Core recovery, epochs, calcareous nannofossil (NN) zones, and New Zealand (NZ) stage correlation
for planktonic foraminifers and bolboforms (PF) and benthic foraminifers (BF), Site U1354. Solid wavy lines =
hiatuses between biozones. See Figure F6 in the “Methods” chapter for NZ stage abbreviations.
8H
8H
1D
21X
10H
50 10H
12H
12H
13H
14H
15H
16D
17H
18H
19H
14H
15H
22X
250
23X
2H
24X
Wc
11H
Pleistocene
11H
BF
20X
9H
9H
13H
Wq
7H
PF
19X
Wq
6H
NZ stage
correlation
18X
NN21
3H
4H
5H
2H
3H
4H
5H
6H
7H
200
NN
Hole
U1354C Epoch zone
Wc-Wo?
BF
NN20
2H
3H
25X
4X
26X
100
27X
300
28X
Wn
8X
9X
29X
30X
11X
32X
12X
350 33X
13X
14X
Wm-Wp
31X
NN16
10X
Pliocene
middle
150
Wc-Wo?
7X
NN15-NN14
6X
Pliocene
early
5X
NN19
Depth CSF-A (m)
PF
Hol.
0
NN
Hole
Hole
Hole
U1354A U1354B U1354C Epoch zone
1H
1H
Core
recovery
NZ stage
correlation
upper Wo
Core
recovery
34X
35X
15X
36X
200
Proc. IODP | Volume 317
17X
early
NN15NN14
upper
Wo
16X
400
35
Expedition 317 Scientists
Site U1354
Figure F14. Planktonic foraminiferal abundance relative to total foraminifers and oceanicity, Hole U1354B (see
Fig. F7 in the “Methods” chapter).
Holocene-Pleistocene
Pliocene
60
Planktonic foraminiferal abundance (%)
50
Extraneritic
40
30
Outer neritic
20
Inner neritic
10
Sheltered inner neritic
0
0
100
200
300
400
Depth CSF-A (m)
Proc. IODP | Volume 317
36
Expedition 317 Scientists
Site U1354
Figure F15. Paleodepth interpretation from benthic foraminifers, Site U1354.
1H
1H
2H
3H
4H
5H
6H
2H
3H
4H
5H
6H
7H
7H
8H
8H
9H
50
10H
11H
12H
13H
14H
15H
16H
17H
18H
19H
Paleodepth
Preservation
Dominant
Abundant
Common
Few
Rare
0
Benthic
foraminifer
abundance
Moderate
Core recovery
Hole
Hole
Hole
U1354A U1354B U1354C
1D
9H
10H
11H
12H
13H
14H
15H
2H
3H
4X
5X
6X
100
7X
8X
9X
10X
11X
150
12X
13X
Depth CSF-A (m)
14X
15X
16X
17X
200
18X
19X
20X
21X
22X
250
23X
24X
25X
26X
27X
300
28X
29X
30X
31X
32X
350
33X
34X
35X
Proc. IODP | Volume 317
Poor
Good
Uppermost bathyal
No paleodepth
estimates
Outer shelf
Caved samples
Middle shelf
Depth range
Inner shelf
400
Hole U1354A
Hole U1354B
Hole U1354C
Estuarine~subtidal
36X
37
Expedition 317 Scientists
Site U1354
Figure F16. Natural remanent magnetization (NRM) paleomagnetic record, Hole U1354A. WRMSL magnetic
susceptibility is also shown.
Hole U1354A
Inclination (°)
Core
-30
30
90
recovery -90
Declination (°)
0
180
Intensity (A/m)
360
10-5
10-3
10-1
Magnetic
susceptibility
(instrument units)
10
100
0
1H
2H
10
3H
4H
5H
20
6H
7H
30
Depth CSF-A (m)
8H
40
9H
50
10H
11H
60
70
80
12H
13H
14H
15H
16D
17H
18H
19H
90
20 mT
Proc. IODP | Volume 317
NRM
Loop sensor
38
Expedition 317 Scientists
Site U1354
Figure F17. Natural remanent magnetization (NRM) paleomagnetic record, Hole U1354B. WRMSL magnetic
susceptibility is also shown.
Hole U1354B
Core
-90
recovery
Inclination (°)
-30
30
Declination (°)
90
0
180
Intensity (A/m)
360
10-5
10-3
10-1
Magnetic
susceptibility
(instrument units)
10
100
0
1H
2H
10
3H
4H
5H
20
6H
7H
Depth CSF-A (m)
30
8H
9H
40
10H
50
11H
60
12H
13H
70
14H
15H
80
20 mT
Proc. IODP | Volume 317
NRM
Loop sensor
39
Expedition 317 Scientists
Site U1354
Figure F18. Natural remanent magnetization (NRM) paleomagnetic record, Hole U1354C. WRMSL magnetic
susceptibility is also shown.
Hole U1354C
Core
recovery -90
60
Inclination (°)
-30
30
Declination (°)
90
0
180
Magnetic
susceptibility
(instrument units)
Intensity (A/m)
360
10-5
10-3
10-1
10
100
1D
2H
3H
80
4X
5X
6X
100
7X
8X
120
9X
10X
140
11X
12X
160
13X
Depth CSF-A (m)
14X
180
15X
16X
17X
200
18X
19X
220
20X
21X
240
22X
23X
260
24X
25X
280
26X
27X
300
20 mT
Proc. IODP | Volume 317
NRM
Loop sensor
40
Expedition 317 Scientists
Site U1354
Figure F19. Raw and Gaussian low-pass filtered data for magnetic susceptibility (loop and point sensors),
natural gamma radiation (NGR), gamma ray attenuation (GRA) bulk density, and color reflectance parameter
b*, Holes U1354B and U1354C. Extreme high and low values, interpreted as noise, are not shown.
Magnetic
Magnetic
susceptibility
susceptibility
loop sensor
point sensor
(instrument units) (instrument units)
0
20
40
0
10
20
30
GRA
bulk density
(g/cm3)
NGR
(cps)
30
50
70
1.8
2.2
b*
-4
0
4
0
50
100
Depth CSF-A (m)
150
200
250
300
350
Raw data
Proc. IODP | Volume 317
Hole U1354B
Hole U1354C
41
Expedition 317 Scientists
Site U1354
Figure F20. GRA bulk density (red) compared to MAD bulk density (yellow). MAD estimates assuming a systematic 3% error (green) are also shown. Core recovery (black = recovered intervals) is also shown.
Bulk density (g/cm3)
Core
recovery 1.50
1.75
2.00
2.25
2.50
0
1H
2H
10
4H
3H
5H
20
6H
8H
Depth CSF-A (m)
30
7H
40
9H
50
10H
11H
60
70
12H
13H
14H
15H
16D
80
Proc. IODP | Volume 317
17H
42
Expedition 317 Scientists
Site U1354
Figure F21. Magnetic susceptibility (loop sensor) and natural gamma radiation (NGR), Holes U1354A and
U1354B. Dashed lines at ~56–60 m indicate the “overlapping problem” in Hole U1354A, for which >100% recovery was reported.
0
0
Hole U1354A
Hole U1354B
Magnetic susceptibility
loop sensor
(instrument units)
Magnetic susceptibility
loop sensor
(instrument units)
10
20
30
40
0
10
20
30
40
0
20
Hole U1354A
Hole U1354B
NGR
(cps)
NGR
(cps)
40
60
80
0
20
40
60
80
100
10
20
Depth CSF-A (m)
30
40
50
60
70
80
90
Proc. IODP | Volume 317
43
Expedition 317 Scientists
Site U1354
Figure F22. (A, B, D) Whole-round and (C, E) section-half P-wave velocities, Holes U1354A, U1354B, and
U1354C. PWL = P-wave logger, PWC = P-wave caliper, PWB = P-wave bayonets.
A
Hole U1354A
PWL
B
1600
1800
Hole U1354B
C PWC
and PWB
P-wave velocity
(m/s)
P-wave velocity
(m/s)
1400
0
Hole U1354B
PWL
1400
1600
1800
P-wave velocity
(m/s)
1300
1500
P-wave velocity
(m/s)
1700
1400
1600
Hole U1354C
E PWC
and PWB
P-wave velocity
(m/s)
1300
1500
1700
100
Depth CSF-A (m)
20
Depth CSF-A (m)
Hole U1354C
PWL
D
40
150
60
200
80
250
PWC, x-axis
Proc. IODP | Volume 317
PWB, y-axis
PWB, z-axis
44
Expedition 317 Scientists
Site U1354
Figure F23. L*a*b* color parameters in uppermost 80 m of Hole U1354B, plotted against natural gamma radiation (NGR) and magnetic susceptibility (loop and point sensors). Note that the similar NGR and magnetic susceptibility values obtained from dominantly sand and marl lithologies show different color characteristics.
Magnetic susceptibility
(instrument units)
0
20
40
60
NGR
(cps)
80
20
40
a*
60
80
L*
-4
0
4
8
-4
0
4
8
15
25
35
45
55
65
0
10
20
Sand
Depth CSF-A (m)
30
40
Marl
50
60
70
80
Point sensor
Loop sensor
b*
Proc. IODP | Volume 317
45
Expedition 317 Scientists
Site U1354
Figure F24. Porosity from MAD catwalk samples compared with adjacent samples from the sample table, Hole
U1354B. A. Cross-plot of porosities resulting from the two sampling methods. Samples below the red line had
more water on the sample table and those above the line had more water when collected immediately on the
catwalk. The linear correlation between the two is shown. B. Porosities plotted as a function of depth. Yellow
= catwalk samples, blue = sample table samples.
A
B
Porosity (%)
30
0
60
40
50
60
70
y = -0.727 + 1.028x R = 0.9462
50
50
45
40
35
35
40
45
50
55
60
Depth CSF-A (m)
Catwalk sample porosity (%)
55
100
Sample table sample porosity (%)
150
200
Proc. IODP | Volume 317
46
Expedition 317 Scientists
Site U1354
Figure F25. Bulk density, grain density, porosity, and void ratios, Hole U1354B (red-rimmed circles) and
U1354C (black-rimmed circles). Core recovery information (black = recovered intervals) is also shown.
Hole U1354B
Hole U1354C
Core
recovery
0
Bulk density
(g/cm3)
1.8
2.0
Porosity
(%)
Grain density
(g/cm3)
2.2
2.6
2.8
30
50
Void ratio
70
1.0
2.0
50
Depth CSF-A (m)
100
150
200
250
300
350
Proc. IODP | Volume 317
47
Expedition 317 Scientists
Site U1354
Figure F26. (A) Automated vane shear (AVS) and (B) fall cone penetrometer (FCP) shear strength and (C) crossplot of AVS and FCP data, Holes U1354B (red) and U1354C (black). AVS test results are given as a function of
pressure in pascals (kPa = kN/m2), whereas FCP test results are given in terms of newtons of kN/m2.
A
Automated vane shear
su (kPa)
20
40
60
Fall cone penetrometer
su (kN/m2)
B
80 100
100
0
0
200
300
C
300
50
50
Automated vane shear
su (kPa)
250
200
150
200
100
Depth CSF-A (m)
Depth CSF-A (m)
100
100
150
50
0
200
0
50
100
150
200
250
300
Fall cone penetrometer
su (kN/m2)
250
250
300
300
350
350
Proc. IODP | Volume 317
150
Hole U1354B
Hole U1354C
48
Expedition 317 Scientists
Site U1354
Figure F27. Gas concentrations (parts per million by volume [ppmv]) vs. depth, Holes U1354A (circles) and
U1354C (squares). A. Methane (C1), ethane (C2), and CO2 in headspace (HS) gas. B. Ratio of methane to ethane
(C1/C2) in HS gas.
HS (ppmv)
A
0.1
1
101
102
103
C1/C2
B
104
105
1
101
102
103
104
0
50
100
Depth CSF-A (m)
150
200
250
300
350
C1
Proc. IODP | Volume 317
C2
CO2
49
Expedition 317 Scientists
Site U1354
Figure F28. Plots of sediment elemental concentrations vs. depth, Holes U1354B (black) and U1354C (red).
A. Carbonate carbon (as CaCO3). B. Total carbon. C. Total nitrogen. D. Total organic carbon by difference
(TOCDIFF). E. Ratio of TOCDIFF to total nitrogen.
A
B
Carbonate (wt%)
0
20
40
60
0
C
Total carbon (wt%)
2
4
6
8
0.00
Total nitrogen (wt%)
0.05
0.10
0
10
20
Depth CSF-A (m)
30
40
50
60
70
80
90
100
D
0.0
TOCDIFF (wt%)
0.5
1.0
E
0
TOC DIFF/Total nitrogen
10
20
30
0
10
20
Depth CSF-A (m)
30
40
50
60
70
80
90
100