Research and Service Projects

This page provides an overview of the major research and service projects that I am currently working on collaboratively, that my student researchers are exploring, or that represent ongoing areas of interest for future projects.

Detrital Garnet Geochronology

Detrital garnet is garnet that grew in one location and then through erosion, transport, and deposition ends up in sediment or sedimentary rock elsewhere. Since detrital garnet is no longer associated with the other minerals with which it originally grew, dating garnet using an isochron method was not practical. During my PhD, I refined a method to make detrital garnet dateable for the first time using leached inclusion from inside the garnet as the second point on the isochron. The methods paper was published as a chapter in an AGU manuscript and a case study paper using this methodology has been published in Geology. (See below - Maneiro et al, 2019, Geology, https://doi.org/10.1130/G46840.1; Maneiro et al., 2022)

The Garnet Age Database

This project started as a side project during my PhD but has grown into a large undertaking. We are actively compiling a database of all peer-reviewed published garnet geochronology that we can locate to-date. We hope to use the database to interrogate community data standards, to identify areas where garnet is present but understudied in the development of future research questions, to provide a valuable community resource, and to examine global trends in garnet ages. A large database project focused on zircon has identified global trends interpreted as supercontinent cycles, but zircon tells a primarily igneous study. If this interpretation is correct, then garnet should tell the complementary metamorphic story.

Dating Earth’s Oldest Garnets

In the search for Earth’s oldest garnet, I have dated garnet from the Acasta Gneiss Complex and Pikwitonei Granulite Domain in the Canadian Shield, from the Narryer Terrane near the Jack Hills field site that is home to Earth’s oldest known terrestrial material (the Jack Hills zircon), from the Barberton Granite-Greenstone Belt and the Limpopo Belt in South Africa, and I am currently working on samples from the Isua Greenstone Belt in Greenland. All of these garnets are more than 2.5 billion years old! Publications related to the garnet geochronology on these sites are in preparation. We also hope to date more old garnets soon. If you have access to old garnet samples, I’d love to talk to you about dating them!

Geoscience Education Research

In college I was a double major in secondary science education and geology, and I hold a high school teaching license in the state of Illinois. I am interested in teaching using research-supported methods and on exploring how to improve the classroom experience for geology students. My classes utilize active learning strategies frequently. I am also currently participating in a geoscience education research project that is exploring the role of assigned seating and room location on student performance in large introductory classes with a collaborator at Austin Peay State University.

Earth’s Early Metamorphism

It’s not enough to simply discover and date Earth’s oldest garnet. We want to use the Earth’s oldest garnets to learn about the conditions during the time the garnet grew and to add to the story of Earth’s earliest metamorphism. Using garnet’s chemistry paired with its age, we can add pressure and temperature constraints to the metamorphism occurring at specific times in Earth’s history to help us better understand the tectonic settings of the time and perhaps address the question of when Earth first experienced modern-style subduction. This work requires careful petrographic analysis of thin sections, SEM and electron microprobe analysis, and pseudosection modeling to add context to the geochronology.

Sustainability @ Wheaton

I am the Theme Coordinator for the Aequitas Fellowship in Sustainability at Wheaton College. Each year, a cohort of 15 incoming freshmen are selected to join the four-year thematic program exploring the principles of sustainability, taking action toward improving sustainability locally, and developing into a sustainable leader. I also serve as the faculty adviser for Wheaton Student Government’s Executive Vice President of Sustainability. I have helped students pass garden, composting, and sustainability coordinator initiatives through Student Government. In Summer 2020, the Wheaton College Garden was installed on Wheaton’s campus. During the summer, I help coordinate volunteers to care for the garden while students are away and guide brainstorming on how to sustainably grow the garden project.

Publications

Journal Articles - Published

• Maneiro, K.A., Jordan, M.K., and Baxter, E.F., 2022, Detrital Garnet Geochronology: A New Window into Ancient Tectonics and Sedimentary Provenance. In Sims, K.W.W., Maher, K., and Schrag, D.P. (Eds.), Isotopic Constraints on Earth Systems Science (pp. 217-236), AGU Monograph Series.

• Cutts, K.A., Maneiro, K.A., Stevens, G., and Baxter, E.F. 2021, Metamorphic evolution for the Inyoni shear zone: Investigating the geodynamic evolution of a 3.20 Ga terrane boundary in the Barberton granitoid greenstone terrane, South Africa, South African Journal of Geology, 124, 1, 163-180.

• Maneiro, K.A., Baxter, E.F., Samson, S.D., Marschall, H., and Hietpas, J. 2019, Detrital garnet geochronology: An example from the French Broad River, Southern Appalachian Mountains, USA, Geology, 47, 12, 1189-1192.

• Collings, D., Savov, I., Maneiro, K., Baxter, E., Harvey, J., and Dimitrov, I, 2016, Late Cretaceous UHP metamorphism recorded in kyanite-garnet schists from the Central Rhodope Mountains, Bulgaria, Lithos, 246-247, 165-181.

Theses

• Maneiro, K.A., 2016, Development of a detrital garnet geochronometer and the search for Earth’s oldest garnet, Doctoral Dissertation, Boston University, Boston, MA.

• Eccles, K.A., 2011, Trace element analysis of rutile and Zr-in-rutile thermometry for southern Appalachian pelitic schists, Honors Program Projects. Paper 10. http://digitalcommons.olivet.edu/honr_proj/10

Conference Abstracts

• Maneiro, K.A., 2022, “Surviving” an introductory geology and environmental science course during pandemic teaching, Geological Society of America Joint North-Central and Southeastern Section Meeting, Cincinnati, OH, USA

• Madsen, L.*, Maneiro, K.A., Brown, A., Dragovic, B., and Stevens, G., 2022, Bulk Lu-Hf garnet geochronology in the Southern Marginal Zone, Limpopo Belt, South Africa, Geological Society of America Joint North-Central and Southeastern Section Meeting, Cincinnati, OH, USA

• Maneiro, K.A., Cutts, K., Baxter, E.F., and Stevens, G., 2018, Earth’s oldest garnet: 3.20 Ga garnet ages robustly constrain the timing of early metamorphism, Goldschmidt Conference, Boston, MA, USA.

• Kone, J., Baratoux, L., Maneiro, K.A., Baxter, E.F., Vanderhaeghe, O., Duchene, S., Ndiaye, P.M., Pitra, P. Dufrechou, G., and Bruguier, O., 2018, Unraveling the ages of HT metamorphism in eastern Senegal: Evidence from U-Pb in-situ analyses on monazite and Sm-Nd garnet geochronology, Goldschmidt Conference, Boston, MA, USA.

• Maneiro, K.A., Baxter, E.F., Samson, S.D., and Marschall, H., 2016, Direct comparison of detrital garnet, monazite, and zircon ages from a southern Appalachian tributary system for the French Broad River, North Carolina, USA, AGU Conference, San Francisco, CA, USA.

• Tappa, M.J., Baxter, E.F., Maneiro, K.A., and Guest, R.E., 2016, Sub-nanogram neodymium isotope measurements on a new Isotopx Phoenix TIMS using 1011 and 1012 ohm resistors, Geological Society of America Annual Meeting, Denver, CO, USA.

• Maneiro, K.A. and Baxter, E.F., 2015, How old is the oldest known garnet, and what can we learn from looking at the published records of garnet geochronology?, Geological Society of America Annual Meeting, Baltimore, MD, USA.

• Eccles-Maneiro, K.A., Baxter, E.F., Samson, S., and Marschall, H., 2015, Detrital garnet geochronology as a complement to detrital zircon and monazite ages from the French Broad River, southern Appalachians, Goldschmidt Conference, Prague, Czech Republic.

• Baratoux, L., Honn, D., Baratoux, D., Eccles, K.A., Baxter, E., Dragovic, B., Block, S., and Jessell, M.W., 2015, Sm-Nd garnet metamorphic ages in the Bole-Nangodi belt, Ghana, Goldschmidt Conference, Prague, Czech Republic.

• Eccles, K.A., Baxter, E.F., Samson, S., and Marschall, H., 2014, Progress in using detrital garnet geochronology as a complement to detrital zircon and monazite ages from the French Broad River, southern Appalachians, Geological Society of America National Meeting, Vancouver, BC, Canada. (Invited)

• Baxter, E.F., Honn, D., Eccles, K.A., and Sullivan, N., 2014, Sub-nanogram Nd isotope analysis via TIMS: Magic potions, fancy resistors, but don’t forget the blank, Goldschmidt Conference, Sacramento, CA, USA.

• Eccles, K.A., Baxter, E.F., Mojzsis, S., Marschall, H., Williams, M, and Jercinovic, M., 2013, Neoarchean metamorphism recorded in high-precision Sm-Nd isotope systematics of garnets from the Jack Hills (Western Australia), AGU Conference, San Francisco, CA, USA.

• Collings, D., Savov, I., Bonev, N., and Eccles, K.A., 2013, Eclogitized serpentinites from the Rhodope Massif: Exploring the fate of serpentinites in the deep mantle.  Goldschmidt Conference, Florence, Italy.

• Collings, D., Savov, I., Eccles, K.A., Baxter, E., and Harvey, J., 2013, Timing and tectonic history of UHP rocks from the Rhodope Massif, Bulgaria.  Geophys. Res. Abs., v. 15.  EGU Conference, Vienna, Austria.

• Carrigan, C.W., Schkerke, C., Eccles K.A., and Eddy, T., 2012, Initial pressure determinations for pelitic schists in the southern Appalachian Blue Ridge.  Geol. Soc. Am. Abstr. Prog, 44 (5).

• Baxter, E.F., Eccles, K.A., and Sullivan, N.C., 2012, Progress in detrital garnet Sm-Nd geochronology: the second point on the isochron.  Goldschmidt Conference, Montreal, Canada.

• Carrigan, C.W., Eccles, K.A., Eddy, T., and Schkerke, C., 2011, Zr-in-rutile thermometry of pelitic schists in the southern Appalachian Blue Ridge.  Geol. Soc. Am. Abstr. Prog., 43 (5), 151.

• Eccles, K.A. and Carrigan, C.W., 2010, Preliminary P-T-t investigation of rutile-bearing pelitic schists in the southern Appalachian Blue Ridge.  Geol. Soc. Am. Abstr. Prog., 42 (5), 48.