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Author ORCID Identifier
https://orcid.org/0009-0006-9063-4120
Date Available
6-18-2027
Year of Publication
2026
Document Type
Master's Thesis
Degree Name
Master of Science (MS)
College
Arts and Sciences
Department/School/Program
Geology
Faculty
Michael McGlue
Abstract
Jackson Lake (Grand Teton National Park, Wyoming, USA) preserves a high-resolution sedimentary archive that records environmental change in the headwaters of the Snake River basin during the Holocene. Mountain watersheds in the Greater Yellowstone region are sensitive to shifts in climate, yet long-term geological records that capture limnological and hydrological responses to these changes remain limited. This study analyzes a 30-m sediment core from Jackson Lake spanning the past ~12,000 years to reconstruct hydroclimatic variability and lake system response through time. An integrated stratigraphic approach combining sedimentology with physical properties (e.g., magnetic susceptibility, water content) and bulk geochemistry (X-ray fluorescence-derived major and trace elements, carbonate content, and total organic carbon) reveals substantial variability in sediment composition throughout the core. The Early Holocene (11,700–8,200 cal yr BP) is characterized by high variability in minerogenic input, consistent with dynamic postglacial watershed conditions, fluctuating effective moisture, and likely relatively low water levels in Jackson Lake. Through the Mid- to Late Holocene (8,200 cal yr BP–present), proxy records show a transition away from minerogenic dominance, instead favoring carbonaceous sedimentation, indicating a high likelihood for deeper lacustrine conditions. A number of factors may be responsible for proxy variability. Lake level change appears to be important, though in Jackson Lake both climatic and tectonic forcing mechanisms likely influenced water level elevation in the Holocene. Evidence from core sediments shows that seismic activity connects to basin-scale limnogeological processes, particularly in the Mid-Holocene; earthquake-related subsidence on the Teton fault is the best explanation for lithofacies, sedimentation rates and geochemical patterns at this time. Landscape evolution, particularly the transition from deglacial to post-glacial environments is also interpreted to play an influential role in patterns of erosion and detrital sediment transport to Jackson Lake from the Snake River. Another factor may be hydrothermal discharge to Jackson Lake, which proxy data suggest was enhanced in the Mid-to-Late Holocene. Together, these results demonstrate that Jackson Lake sediments record the combined influences of tectonics and hydroclimate, providing new insight into long-term environmental dynamics in the northern Rocky Mountains.
Digital Object Identifier (DOI)
https://doi.org/10.13023/etd.2026.327
Archival?
Archival
Funding Information
National Science Foundation Grant #1932808 (2020)
Charles A. and June R.P. Ross Geological Society of America Graduate Student Research Grant (2025)
David Worthington Named American Association of Petroleum Geologists Grant (2025)
Association of Women Geoscientists Research Scholarship (2025)
Recommended Citation
Portwood, Abigail L., "A NOVEL HIGH-RESOLUTION HOLOCENE PALEO-PROXY RECORD OF SNAKE RIVER HYDROLOGY FROM GRAND TETON NATIONAL PARK (WYOMING, USA)" (2026). Theses and Dissertations--Earth and Environmental Sciences. 125.
https://uknowledge.uky.edu/ees_etds/125
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