24 Undergraduate Research Posters
This poster session highlights geoscience research conducted and presented by undergraduate students. Abstracts must be written by students (but may include non-student co-authors). Research topics may include any area of the earth sciences.
Thursday, 23 April 2026
8:00 AM - 5:30 PM
LMH, 5th Floor Chapel
Reconstructing Cretaceous-Miocene Thermal History in the Central Klamath Mountains using (U-Th)/He Thermochronology
Paper number: 24-9
Program: Technical Sessions
Time: 8:15 AM – 8:15 AM
Authors
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Katalina NealCalifornia State Polytechnic University, Humboldt, Arcata, California
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Angel GonzalezCalifornia State Polytechnic University, Humboldt, Arcata, California
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Adaline BrabantCalifornia State Polytechnic University, Humboldt, Arcata, California
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Xander LewisCalifornia State Polytechnic University, Humboldt, ARCATA, California
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Angelina ReganCalifornia State Polytechnic University, Humboldt, Arcata, California
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Francis SousaOregon State University, Corvallis, OR
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Melanie MichalakCalifornia State Polytechnic University, Humboldt, Arcata, CA
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Jaclyn BaughmanCalifornia State Polytechnic University, Humboldt, Arcata, CA
Abstract
The Klamath Mountains Province (KMP) in northern California and southern Oregon consists of Cambrian to Cretaceous accreted terranes intruded by Jurassic-Cretaceous plutons. Since terrane accretion was complete, the KMP experienced significant burial during a Cretaceous marine transgression, and subsequent exhumation associated with regional tectonic activity such as the Eocene Siletz terrane collision to the north, Tertiary La Grange detachment faulting, and Miocene regional rock cooling.
Our cohort of six undergraduate students and faculty mentors investigate the extent and influence of these events on the central KMP using zircon (U-Th)/He (ZHe, closure temperature (Tc) ~180°C, n=10; 2 samples) and apatite (U-Th)/He (AHe, Tc ~60°C, n=24; 5 samples) thermochronology. We target the central KMP because the absence of any preserved Cretaceous sedimentary record, unlike the southern and eastern KMP, suggests 1) the region was a topographic highland in the Cretaceous and never experienced burial, or 2) was overlain with sedimentary rocks that have since completely eroded. Combined ZHe-AHe thermochronology of the Russian Peak and English Peak plutons will allow us to assess these competing scenarios. In addition, our new data will allow us to investigate the causes of previously reported highly dispersed ZHe dates in the central KMP.
Elsewhere within the central KMP, we aim to characterize the spatial pattern of exhumation across the Ironside Mountain Batholith with new data, and the western extent of regionally documented Miocene exhumation using new AHe data from the Ammon Ridge pluton. We evaluate geologically plausible thermal histories through both inverse and forward thermal modeling, synthesizing our data with published and in progress thermochronometric data from the south-central KMP to present a more complete picture of crustal cooling and exhumation across the province.
Geological Society of America Abstracts with Programs. Vol. 58, No. 3
doi: 10.1130/abs/2026CD-410936
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