10 Advancements in the Proterozoic tectonics of western North America (Posters)

This session highlights recent developments in understanding of the Proterozoic tectonic record of western Laurentia, particularly its relation to critical mineral resources. Insights derived from all disciplines and approaches are welcome.

Monday, 18 May 2026
8:00 AM - 5:30 PM
Alvarado D/E

Constraining Pressure–Temperature Conditions and Tectonic Setting of the Mount Owen Batholith at the Archean-Proterozoic boundary: Teton Range, Wyoming

Paper number: 10-1
Program: Technical Sessions
Time: 8:00 AM – 8:00 AM

Authors

Abstract

Reconstructing global Archean tectonic and magmatic events is challenging due to the limited exposure of unaltered rocks of this age. The Wyoming Province exposes evidence of Archean tectonic events from 3.6 to 2.5 Ga. Before 2.84 Ga, rocks of the middle Wyoming Province do not seem to have originated in a setting that is comparable to modern-day plate tectonics. Modern plate tectonics can reasonably describe the plutonic and tectonic events that occurred on the province's western edge between 2.68 and 2.67 Ga, but later Archean to Proterozoic tectonic activity is not well constrained. This study focuses on the Mount Owen batholith, a late-Archean peraluminous leucogranite in the Teton Range, to assess the tectonic setting of the batholith’s intrusion.

The Mount Owen batholith in the Teton Range is the largest granitic intrusion in Wyoming Province, the final Archean felsic calc-alkaline igneous event in the Teton Range (~2.55-2.50 Ga), and part of the last major Archean magmatic event in the Wyoming Province. The batholith is considered a stitching pluton, as it intruded along a major Archean tectonic suture between gneisses of different cratonic affinities. However, the tectonic setting for the formation of this batholith is cryptic. To assess various tectonic models for Late Archean crustal evolution, this work focuses on constraining the chronology, magmatic source, and pressure–temperature conditions of batholith emplacement. This study uses integrated geochemical, petrological, and mineralogical investigations of Mount Owen leucogranites. Zircon age and trace element analyses constrain the timing of magma crystallization and offer estimates of magma temperature and melting depth, while whole-rock geochemical data are used to identify magma composition and melting source materials. These data enable assessment of whether the batholith developed in a lower-pressure extensional environment or in a collisional setting with extensive crustal thickening. Using petrographic observations and mineral chemistry, the origin of garnet inside the batholith is evaluated to determine if garnet originated directly from magma, was inherited from source rocks, or represents interactions between melt and solid residues. To quantify the pressure-temperature conditions of magma formation, whole-rock and mineral data will be integrated using thermodynamic modeling. This project compiles a history of the Mount Owen batholith that details the possible tectonic setting that created this piece of ancient crust.

Geological Society of America Abstracts with Programs. Vol. 58, No. 4

doi: 10.1130/abs/2026RM-410508

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