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Group Members

Postdoctoral Researchers

Piccione Headshot

Dr. Gavin Piccione ( – Postdoctoral Research Associate, 2023-Present

B.S. Geosciences (Summa cum Laude), Stony Brook University, 2016; Ph.D. Earth & Planetary Sciences, University of California Santa Cruz, 2023;

I am a geochemist and geochronologist with broad interests in the processes that link Earth’s climate and hydrosphere through time. My research leverages both traditional and novel terrestrial sedimentary archives to create time-resolved datasets that describe paleoclimate evolution on decadal to million-year timescales. I have applied these methods to reconstruct the rates of Antarctic ice sheet growth and retreat, and the impact of glaciers on global geochemical cycles. While at Brown, I am working with Dr. Daniel Ibarra on projects investigating the temporal variability of hydroclimate in the western US, as well as weathering beneath ice sheets. Before arriving at Brown, I earned my bachelor’s degree (with Honors) in Geoscience at Stony Brook University, and my PhD in Earth and Planetary Science at the University of California Santa Cruz.


Graduate Students

Catherine (Cathy) A. Gagnon (IBES Profile; LinkedIn) – DEEPS Ph.D. Candidate (4th year) – Department of Energy Office of Science Graduate Student Research (SCGSR) program recipient

B.S. Geoscience (w/ hydrogeology concentration), The Pennsylvania State University, 2020

Cathy is a 4th year PhD candidate at Brown University excited about stable isotope geochemistry, terrestrial paleoclimatology, and volcano-sedimentary lithium deposits. Broadly speaking, she uses a variety of stable isotope and mineral characterization methods to understand the geological, environmental, and thermodynamic mechanisms controlling lithium enrichment in sedimentary rocks. Her geological field training involved mapping landscapes in Montana, Wyoming, Utah, and Idaho. Current research interests have since taken her to the arid and semi-arid basins of California, Nevada, and the Atacama desert in Chile. She has conducted research as an intern for Lithium Americas and will be conducting research at the Berkley National Lab this Fall/Winter as part of the DOE SCGSR program. In addition to research, Cathy loves winter hiking, rollerblading, and playing ice hockey around the greater Boston area where she is from. She resides in Norton, MA with her fiancé, little black cat, and kind and goofy dog, Penny.

Sebastian (Seb) Muñoz (IBES Profile) – DEEPS Ph.D. Candidate (3rd year) – Brown Presidential Fellow & National Science Foundation Graduate Research Fellow – co-advised by Larry Smith

B.S. Geological Sciences (hydrogeology honors) and B.A. Liberal Arts, University of Texas, Austin, 2018

Sebastian spends all of his time thinking about, studying, or boating on rivers. He is interested in how surface water chemistry will change in response to human activities and climate change. Previous work includes studying rock glaciers contributions to river flows in northern Chile, and understanding surface water and groundwater interactions downstream of a dam in the Colorado River near Austin, TX.

M. Justin Custado (IBES Profile) – DEEPS Graduate Student (2nd year)

B.S. Chemistry, University of the Philippines – Diliman, 2015 & M.S. Environmental Science, University of the Philippines – Diliman, 2021

Justin‘s research interests span broadly within the fields of aquatic geochemistry (e.g., spatiotemporal variation of chemical species through water systems) and hydrology related to climate processes (e.g., investigating the response of hydrological parameters to events such as the ENSO). Originally from a hot and humid country (the Philippines), he moved to Providence in the Fall of 2022 and is currently struggling with the cold New England weather.
  • Mónica Geraldes Vega – DEEPS Graduate Student (1st year) – co-advised by Kim Cobb

B.A. Geological Sciences, Mount Holyoke College, 2022

Mónica is broadly interested in paleoclimate, biogeochemistry, and geochronology. Her undergraduate work at Mount Holyoke College involved deciphering siliciclastic paleolake levels of a Jurassic rift lake in Western Massachusetts using physical and geochemical proxies. At Brown, she’s switched gears a little and is into learning about more geologically recent carbonate records via stalagmite samples from the Philippines. She is driven by questions related to tropical paleoclimate and general excitement about learning and sharing knowledge. She is also enjoying her transition from her native Dominican Republic to Providence life, where she is getting better at cooking every day.


Research Technicians

Jesse Miller, A.B. with Honors, Geological Sciences, Brown University, 2023

Summer 2022 SPRINT|UTRA Award and Research at Brown Grant

2023 GSA NE-SE Regional Meeting Presentation: Temperature Dependent Dissolution Experiments of Basalt, Dacite and Pumice from The Little Deschutes River Valley

Senior thesis: Temperature dependent dissolution experiments of basaltic andesite, dacite and pumice from the Little Deschutes River Valley, Oregon

Manuscript Forthcoming!



Anna Dubey, Sc.B. Candidate, Ecology, Evolution, & Organismal Biology, Brown University, 2025.

Anna is a fourth-year student at Brown studying ecology, evolution, and organismal biology. Her research interests lie at the intersection of evolutionary biology and paleoclimate. She is currently working on a project with Gavin using ostracod data from Silver Lake, CA to produce a temperature record. Other than research, her activities include writing for Encyclopedia Britannica and teaching environmental science to high school students.

Celia Kong-Johnson, A.B. Candidate Geology-Chemistry and Applied Math, Brown University, 2025

Fall 2023 SPRINT|UTRA Award

AGU 2023 Fall Meeting Presentation: Insights into paleorainfall variability in the Philippines using the geochemistry of a speleothem spanning 28 to 51 kyrs BP

I am a currently a fourth-year at Brown University and plan on concentrating in geochemistry, with a possible double concentration in applied math. I am most interested in paleoclimate studies and applying these findings to future climate change research. I am currently working with Natasha, analyzing carbon and oxygen isotope records in speleothems from Colombia and the Philippines to help model past vegetation and rainfall in the area. Outside of academics here at Brown, I am on the Track and Field team. I also enjoy visiting and exploring National Parks with my family.

T Gotsch Pic

Tee Gotsch, A.B. Candidate Geology-Biology and Music, Brown University, 2026

Summer 2024 SPRINT|UTRA Award

Tee is a third-year undergraduate studying Geology-Biology and Music. They are broadly interested in soil-groundwater systems and agricultural biogeochemistry, and work with Justin to better understand chemical weathering processes in the Philippines.


Former Group Members


Dr. Natasha Sekhon (Website; IBES Profile) – Voss Postdoctoral Research Associate and Presidential Diversity Postdoctoral Fellow, 2021 to 2023

Current: Assistant Professor at Occidental College!


Dr. Kristina Butler (; – NSF EAR Postdoctoral Fellow, 2023

Current: Assistant Professor at UT Dallas


Dr. Evan Ramos (Website) – NSF EAR Postdoctoral Fellow, 2021 to 2023; Affiliated Postdoc 2023-2024 (Primarily at Rice University)

Current: Assistant Professor at University of Pittsburgh


Graduate Students

Theodore (Ted) Bobik – Sc.M. Earth, Environmental & Planetary Sciences, Brown University, 2024

Thesis: Filling in the Gaps: Paleosols as Regional Recorders of Hydroclimatic Change in Northeast China at the Cretaceous – Paleogene

Paper forthcoming!


Jonah Bernstein-Schalet, Sc.B. Candidate Geology-Biology, Brown University, 2024.

2023-24 Voss Undergraduate Fellowship Award

AGU 2023 Fall Meeting Presentation: Linking Post-Wildfire Soil Geochemistry to Carbon Processes and Chemical Weathering

GSA NE 2024 Presentation: Wildfire impacts on soil chemistry and the role of pyrogenic carbon in soil mineral transformation

Senior Thesis: Linking Stream Chemistry to Soil Biogeochemistry to Investigate the Environmental Legacy of Wildfire in Oregon’s West Cascades

A young white adult is pictured squatting outside in front of green trees and shrubs, with mountains a town in the distance. They are smiling and squinting, facing the sun. They’re wearing a light blue jean jacket over a dark green shirt, a multi-colored bag strap on their left side, and a small silver necklace. Whitney Vieira Ribeiro, Sc.B. Geology-Biology, Brown University, 2024.

Senior thesis: Tracking the Impact of the K/Pg on Pelagic Shark Diversity Using Dermal Denticles


Marina Benson, Sc.B. with Honors, Geology-Biology and B.A. Music, Brown, 2024

2023-24 Voss Undergraduate Research Fellow

Senior thesis: Edgartown Great Pond is Turning Green! The Ecological Impacts of Nitrogen Pollution on Coastal Estuaries

Daniel Graves, Sc.B. with Honors, Environmental Sciences, Brown University, 2024

GSA NE Presentation: Variability of groundwater recharge in variable climates: a groundwater flow model for the Southern Great Basin

Senior thesis: Variability of groundwater recharge in variable climates: a water-energy balance groundwater model for the arid Southern Great Basin

Shaw Miller, Sc.B. with Honors, Geology-Biology, Brown University, 2023.5

Summer 2022 SPRINT|UTRA Award

2023 Sarah LaMendola Undergraduate Research Award

2023 AGU Fall Meeting Presentation: Identifying drivers of hydroclimate change during Marine Isotope Stage 5 in Owens Valley CA using carbonate clumped isotopes.

Senior thesis: Identifying drivers of hydroclimate change during MIS 5 in Owens Valley, California using carbonate clumped isotopes
Manuscript Forthcoming!

Maira Rojas-Tineo, Sc.B Engineering, Brown, 2025

Fall 2023 SPRINT|UTRA Award



Annabelle Gao, Sc.B. Geology-Chemistry, Brown University, 2023

Coauthor on Gagnon et al. (2023, GSA Bulletin) and several forthcoming manuscripts.

Masters at Centre Européen de Recherche et d’Enseignement en Géosciences de l’Environnement; soon to be Ph.D. student at Boston University.


Christina Marsh, DEEPS Leadership Alliance REU, Summer 2022, B.A. Environmental Analysis, Pomona College, 2023


Manuscript In Revision!

Now a CLIMATE Justice Initiative Fellow at UC Irvine

Mia Prausnitz-Weinbaum, Sc.B. Candidate Environmental Studies, Brown University, 2024




Natalie Chang, A.B. Candidate, Geology-Biology and Modern Culture & Media, Brown University, 2024

Summer 2022 SPRINT|UTRA Award



Elizabeth (Lizzy) Gaviria (LinkedIn) – DEEPS Leadership Alliance REU, Summer 2021/Independent Study 2021-22 Academic Year – B.S. Environmental Science, Rice University, 2022

2022 AMS Annual Meeting Presentation: Modeling seasonal and interannual climate variability in modern precipitation pathways across western North America using air parcel trajectories

Coauthor on Gagnon et al. (2023, GSA Bulletin)

Now a Grants Analyst at Tennessee Department of Environment and Conservation

Lab Visitors

Dr. Jaivime Evaristo – Assistant Professor, Utretch University – Spring 2023 (Website)

Bryce Belanger – Ph.D. Candidate, Vanderbilt University – Summer 2023

Vigash Ravi – Undergraduate, U of Washington – Summer 2023

Jiquan Chen – Ph.D. Candidate, China University of Geosciences (Beijing) – Fall 2023 to Spring 2024

Xueyao Cheng – Graduate Student, Stanford University, Spring 2024

Emily Nigro – Graduate Student, Stanford University, Spring 2024


Lab Affiliates/Collaborators at Brown

Dr. Gerrit Budde – Assistant Professor, DEEPS, 2020-Present

Dr. Xiaojing Du – Postdoc, DEEPS/IBES, 2021-2023 (Now faculty at GMU)

Dr. Weimin Si – Senior Research Associate, DEEPS, 2021-Present

Jared Nirenberg – Graduate Student, DEEPS, 2021-Present

Dr. Christopher W. Kinsley – Postdoc at Berkeley Geochronology Center, 2022-Present

Dr. Dean Kahn – Research Associate, DEEPS, 2022-Present

Dr. Soumen Mallick – ICPMS Analysis Specialist/Research Scientist, DEEPS, 2022-Present

Riley Havel – Graduate Student, DEEPS, 2022-Present

Dr. Blake Hodgin – Assistant Professor (Research), DEEPS, 2023-Present

Dr. Anna Waldeck – Agouron Postdoctoral Research Fellow, DEEPS, 2023




Knuckles,  Gigi, and Penny