Earth and Planetary Sciences ETDs

Publication Date

Spring 5-2018

Abstract

Many researchers have studied the Guadalupe Mountains in detail and starting with King (1948), many of them have speculated about the timing of the uplift of the Guadalupe block. There are several competing hypotheses including Laramide, Basin and Range, and Rio Grande Rifting uplift scenarios. Using uranium-lead dating of scalenohedral spar found in small vug caves throughout the study area, I have dated the episodes of spar formation to two major phases, 36 to 33 Ma and 30 to 27 Ma. These two episodes of spar formation are in good agreement with the time frame of the ignimbrite flare up during the formation of the Basin and Range. I have also dated several older phases, all the way back to ~180 Ma, which all correspond to nearby (<100 >Km) known volcanic activity and provide a good argument for the hydrothermal genesis of the spar. By determining the depth of formation of the spar through a new speleogenetic model (supercritical CO2), age dating the cave spar through U-Pb dating techniques, and finding the temperature of formation of the spar through a newly calibrated δ88Sr thermometer and fluid inclusion assemblage analysis, I have been able to develop a thermochronometer in a region that has not had the typical apatite fission track and apatite thorium-helium methods available. Using this new method, along with U-Pb dating of calcite vein spar from the Border Fault Zone, I have constrained the timing of the uplift of the Guadalupe block to between 27 and 16 million years.

Degree Name

Earth and Planetary Sciences

Level of Degree

Doctoral

Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Dr. Yemane Asmerom

Second Committee Member

Dr. Victor Polyak

Third Committee Member

Dr. Karl Karlstrom

Fourth Committee Member

Dr. Matthew Lachniet

Language

English

Keywords

Guadalupe Mountains, supercritical CO2, cave spar, geochronometer, delta88Sr, fluid inclusion, spar horizon

Document Type

Dissertation

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