Detrital Zircon U-Pb Geochronology and Provenance of the Eocene Claron Formation, Southern Utah, USA
Graduation Term
Spring 2025
Degree Name
Master of Science (MS)
Department
Department of Geography-Geology: Hydrogeology
Committee Chair
David Malone
Committee Member
James "Jed" Day
Committee Member
Michael Braunagel
Abstract
Three catastrophic landslides make up the recently discovered Oligocene-Miocene Marysvale Gravity Slide Complex (MGSC), those being the Markagunt (MGS), Sevier (SGS), and Black Mountains (BGS) gravity slides, in south-western Utah. These collapses are hypothesized to have been driven by the igneous inflation of the Marysvale Volcanic Field (MVF). Here I assess the pre-volcanic strata that form the floor and environs of the MVF to constrain the regional paleogeography and sediment sourcing prior to volcanism. Detrital zircon U-Pb analyses (LA-ICPMS) were conducted on sandstones and the matrix of conglomerate beds of the Eocene Claron Formation (STATS) and the overlying Oligocene Conglomerate at Boat Mesa (STATS) and show a shift in provenance over time. The detrital zircon age spectra of the pink member (lower) of the Claron Formation is dominated by Mesoproterozoic zircons that I interpret as being recycled from Neoproterozoic Proterozoic-Mesozoic strata exposed in the Sevier thrust belt, which was proximal and to the west of the Claron Basin. The overlying white member of the Claron Formation also is dominated by Mesoproterozoic zircons but shows a larger presence of Mesozoic grains. All Claron pink samples are statistically indistinguishable. The Conglomerate at Boat Mesa is dominated by Jurassic grains that were sourced from the Cordilleran arc in the Sevier hinterland, indicating the loss of prominence of the Sevier fold and thrust belt at this latitude by Eocene time. The Conglomerate at Boat Mesa is overlain by the volcanogenic Brian Head Formation, which was sourced by the Indian Peak Caldera complex, several hundred kilometers to the west. Thus, these data indicate that the Laramide compression in this region had abated by the end of Claron deposition which is revealed by a shift in sediment provenance from proximal sources in the Sevier foreland to distal sources in the Sevier hinterland and the Sierran magmatic arc.
Access Type
Thesis-Open Access
Recommended Citation
Cull, Kennedy, "Detrital Zircon U-Pb Geochronology and Provenance of the Eocene Claron Formation, Southern Utah, USA" (2025). Theses and Dissertations. 2073.
https://ir.library.illinoisstate.edu/etd/2073
