255 Broad Applications of Thermochronology to Understanding Geologic Rates and Processes Through the Sedimentary Record
This session showcases the many ways mid-to-low temperature thermochronometers can be used in isolation or with additional chronometers to understand geologic processes preserved in the sedimentary record such as sediment provenance, source exhumation, burial and/or erosion history.
Wednesday, 22 October 2025
8:00 AM - 12:00 PM
HBGCC, 304C
Thermal Characterization and Exhumation of Northwest San Juan Basin Area, NM
Paper number: 255-5
Program: Technical Sessions
Time: 9:20 AM – 9:35 AM
Authors
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Ryan LearyNew Mexico Institute of Mining and Technology, Socorro, New Mexico
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Shari KelleyNew Mexico Bureau of Geology and Mineral Resources, Socorro, New Mexico
Abstract
The San Juan Basin (SJB), located in southwestern Colorado and northwestern New Mexico, which preserves Paleozoic through middle Cenozoic strata, formed as a partitioned basin approximately 80 Ma in response to the Laramide orogeny. The SJB is a commercially mature, petroleum-producing basin that is currently being explored for CCUS and geothermal resources. Modern heat flow within the SJB is spatially variable with higher geothermal gradients in its northern and eastern portions. Determining thermal history of the basin is essential for understanding capacity for carbon storage and geothermal exploration. We present thermochronometric analyses of two surface and two subsurface samples to constrain spatial-temporal thermal evolution of the northwestern San Juan Basin.
Apatite (U-Th)/He thermochronometric analyses were conducted on Cliff House and Kirtland Formation outcrops and on subsurface samples of the Ojo Alamo and Pictured Cliffs Formations from a DOE funded, CCUS project pilot-well. In addition, vitrinite reflectance data and 1D basin modelling constrain possible time-temperature pathways of the samples in an area where no previous studies have constrained the uplift/exhumation of the Hogback Monocline using thermochronometry.
Modeling suggests that elevated subsurface temperatures developed simultaneously with regional late Oligiocene volcanism in the San Juan Volcanic field and timing of maximum burial in the SJB. Late Miocene to Pliocene cooling/exhumation through the apatite (U-Th)/He partial retention zone support stratigraphic evidence of the Colorado Plateau uplift, possibly regional epeirogenic uplift driven by mantle processes.
Geological Society of America Abstracts with Programs. Vol. 57, No. 6
doi: 10.1130/abs/2025AM-413752
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