April 15th, 2025
Schedule of Events:
6:00-7:00: Social Hour and Poster Session
7:00-7:30: Dinner
7:30-7:45: CGS Announcements and Raffle
7:45-8:00: Student Presentation (Sophia Ortner)
8:00-8:15: Student Presentation (Anthony Delgadillo Salas)
8:15-8:45: Scholarship Awards
UCSB
Title: Origin of unique scapolite (silvialite)-bearing mafic granulite xenoliths as deep arc cumulates
Abstract: Mafic granulite xenoliths from the Great Falls Tectonic zone, Montana likely formed as cumulates from arc magmas; they are enriched in Sr, Ba and Eu and depleted in Nb, Ta and Ti (Ringwood et al., 2024, CMP). These cumulates re-equilibrated at the granulite to eclogite facies and contain the sulfur-bearing end-member of scapolite (silvialite), clinopyroxene, plagioclase, garnet, and kyanite intergrown with quartz. In one sample, silvialite crystallizes in a radial pattern surrounding a currently unknown heterogeneous center phase that contains small sulfides, forming multiple rosettes seen throughout the thin section (Fig 1). Silvialite and kyanite stability fields overlap with the intersection of several thermobarometers applied to these samples, indicating equilibration at 1.8-2.3 GPa and 890-1000℃. These conditions correspond to modern mantle depths, however it is unknown whether these rocks truly crystallized in the mantle, or at the base of a tectonically thickened lower crust. This project aims to use the isotope geochemistry of the rocks (both stable and radiogenic) to determine whether they initially crystallized in the lower crust or mantle lithosphere and the degree to which they incorporated pre-existing continental crust. Such information will inform models of continental crust formation and evolution.
Bio: My name is Sophia Ortner, and my life revolves around geology and research. I am a first year Masters student studying under Dr. Roberta Rudnick at the University of California: Santa Barbara. I graduated with my bachelors of science in geology from the same university after spending two years as an undergraduate research assistant to Dr. Rudnick and Dr. Mary Ringwood, where I worked to date the eruption age of Big Slide Diatreme, in Montana, and learned how to do thermobarometry on a suite of metapelites from Bournac, France. Now I am continuing my research in Montana with Dr. Rudnick and I use geochemistry to understand lower crustal and mantle interactions and processes. Outside of my work I have unlimited support from my mom and dad, as well as my sweet cat, named Widget, who provides me much needed stress relief in the form of entertainment and love. I spend most of my free time knitting sweaters, reading science fiction, or hiking with friends. I am very excited for the opportunity to present the work I have accomplished thus far during my masters degree, and to grow as a presenter and scientist.
Cal Lutheran
Title: Evidence for Late Holocene Anthropogenic Impacts and Climate Change in Black Lake: Novel Insights from California's Dune Lake System
Abstract: Black Lake, one of the “Dune Lakes” located within San Luis Obispo County’s Callender Dunes, is a sedimentary archive reflecting millennia of climate change and anthropogenic activity. The Dune Lake wetlands presently harbor several threatened and endangered species, suggesting long-term persistence of these freshwater aquatic ecosystems. Urban expansion, agricultural groundwater extraction, and drought have recently put these rare ecosystems at risk. Only Black Lake is known to have been perennially wet since the 20th Century. In an effort to disentangle natural and anthropogenic causes of environmental change at the site, two lake sediment cores were collected in collaboration with the U.S. Fish and Wildlife Service, 3.96m and 6.98m respectively. These records span the past 3300 years. Paleoenvironmental proxies indicate dynamic shifts throughout the late Holocene, including a dramatic decline in macroscopic charcoal in the upper 60 centimeters, potentially tied to a decline in native burning after European colonization. Pre-1800 CE fire regimes likely reflect both periods of drought and indigenous Chumash land use practices, suggesting elevated fire activity that plummeted after European settlement. The cores contain notable sand deposits and positive magnetic susceptibility excursions in the top two meters of both cores, reflecting high-energy depositional events, presumably aeolian in origin. The presence of high organic content peat and the persistence of Cirsium loncholepis (La Graciosa thistle) at the site indicate that Black Lake has likely remained a wetland throughout the Holocene.
Bio: Anthony Delgadillo Salas is a graduating senior at California Lutheran University, majoring in Environmental Science with a minor in Data Science. Since 2022, Anthony has been working in the PEARL (PaleoEnvironmental Analysis and Research Laboratory) with Dr. Robert Dull at CLU. His research focuses on Holocene paleoenvironmental reconstruction using wetland sediment archives from Southern California and Central America. His primary focus over the past year has been a 3000-yr old late Holocene record from the Dune Lakes region of San Luis Obispo County.
A first-generation Mexican American student, Anthony has been actively involved in TRIO programs, initially with Upward Bound, then via Student Support Services, and culminating with the Ronald E. McNair Postbaccalaureate Scholars Program. He also serves as a geoscience instructor for Upward Bound at Cal Lutheran, where he helps mentor and educate students in earth and environmental sciences.
Anthony participated in a Research Experience for Undergraduates (REU) at Pennsylvania State University in summer of 2024, which focused on meteorology and climate science. Anthony plans to continue his research and mentorship in a geosciences PhD program beginning in Fall 2025, where he hopes to broaden his research experience, while lending support and inspiration to the next generation of students.
UCSB
Title: Uplift History of Western Santa Cruz Island: Mapping Marine Terraces and Calculating Shoreline Angle Elevations
Abstract: Long-term uplift for the westernmost segment of the Transverse Ranges is recorded by uplifted marine terraces on the Northern Channel Islands in Southern California. At Santa Cruz Island, Pinter et al. (1998) estimated a steady uplift rate of ~0.1 mm/yr, but advances in map resolution and geospatial analysis, since the time of previous studies allow for more precise terrace mapping and uplift rate calculations. This study quantifies uplift rates on western Santa Cruz Island by analyzing terrace distribution and shoreline angle elevations by comparing previous age constraints (Pinter et al., 1998; Muhs et al., 2021). Using LiDAR and Surface Classification Models, we spatially mapped the distribution of terraces, and preliminary analyses determined that uplift rates differ significantly depending on the age model used for the highest terrace; one suggests sustained uplift since formation, and the other implies variable rates through time. These results indicate a need to reassess previous estimates for tectonic uplift and relative sea level change to refine our understanding of Santa Cruz Island’s tectonic deformation history and associated seismic hazard.
Bio: Brenna Lonsdale is an undergraduate Earth Science student with an emphasis in geology at the University of California, Santa Barbara. Her research focuses on using LiDAR data and surface classification models to analyze marine terrace uplift rates on Santa Cruz Island. Brenna has experience with GIS, remote sensing, and fieldwork, and is particularly interested in tectonic geomorphology and geospatial analysis. She aims to pursue a career in natural hazard research.
UCSB
Title: Characterizing Organic Carbon Burial in the Wax Lake Delta, Louisiana
Abstract: Louisiana's coastline is experiencing rapid land loss due to human activity, climate change, and natural processes. Engineered river diversions in the Mississippi River basin, designed to mitigate land loss, have caused formation of deltas in coastal areas, such as the Wax Lake Delta offshore Louisiana. These human-made deltas are found to enhance carbon burial in river deltas, holding significant implications for advancing our understanding of river-delta systems in the global carbon cycle. In particular, rivers deliver carbon to the delta, whereas the delta’s local biomass fixes carbon as well. Yet the relative roles of these processes in enhancing carbon storage in deltas remain less well understood. The study focuses on the Wax Lake Delta, Louisiana, to understand how river-delta systems transport and bury carbon in coastal areas. The objective is to characterize the organic carbon burial in the Wax Lake Delta. Methods of the study include X-ray fluorescence (XRF) for non-destructive elemental analysis, decarbonation to remove inorganic carbon, and elemental analysis for total organic carbon content measurements. By comparing the Al/Si ratios (as a proxy for grain size) to the total organic carbon content, we aim to determine the organic carbon loading of 61 samples collected from the river and deltas. The organic carbon loading of the delta sediments will be compared to that of the river sediments to evaluate contributions from the river versus the local biomass of the delta. This comparison will help to identify the source of the organic carbon, shedding new light on carbon transfer and sequestration at the interface between lands and oceans.
Bio: Sandra Jacob is a fourth-year undergraduate studying geology at UC Santa Barbara, with aspirations to become a hydrogeologist. She began working with Dr.Gen Li as a lab assistant during her third year and is now conducting her senior thesis research on characterizing organic carbon burial in the Wax Lake Delta, Louisiana, using geochemical techniques. In addition to her research, she serves as the Co-President of the Earth Science Club and as the undergraduate representative on the Justice, Equity, Diversity, and Inclusion (JEDI) committee for UCSB Earth Science. Outside of academics, she enjoys camping with friends and woodworking.
Cal Lutheran
Title: Utilizing foraminifera to reconstruct paleo-methane seeps and paleoceanographic changes in the Norwegian Sea since the last glacial maximum
Abstract: We studied six taxa of benthic and planktonic foraminifera (i.e., Cassidulina spp., Cibicides lobatulus, Elphidium spp., Melonis barleeanus, Neogloboquadrina pachyderma, Nonionella labradorica) from one gravity core (GC01; 220 m water depth) collected from the Hola trough, off the coast of the Lofoten Islands (68°55.123’ N 14°17.194’ E). We selected this core because it was from an area where seep carbonate occurrence indicated a long history of methane emissions (Sauer et al., 2017). By analyzing benthic foraminiferal assemblages, studying the possible impact of methane on the preservation of foraminiferal shells (Foram Preservation Index (FPI); Poirier et al., 2021), and analyzing the stable isotope composition of the isolated specimens (𝛿¹⁸O and 𝛿¹³C) we aimed to understand how benthic foraminifera responded to potential methane activity and, possibly, paleoceanographic changes during the most recent geological past (~16 kyr). Stable isotope data do not suggest methane seepage close to the site because there is no clear excursion in 𝛿¹³C in any of the genera. Notably, Cassidulina and Elphidium experienced a marked change in their preservation with more poorly preserved assemblages at the base of the core. These results, combined with chemical data (X-Ray Fluorescence) collected on the whole core, suggest paleoceanographic changes.
Bio: I am a junior undergraduate student, from Newbury Park, California, at California Lutheran University studying environmental science and political science. After graduation, I hope to go to graduate school to study environmental policy, specifically environmental justice. In my free time, I like to watch sports and go to the gym with my brothers.
