GSA Annual Meeting in Indianapolis, Indiana, USA - 2018

Paper No. 32-26
Presentation Time: 9:00 AM-5:30 PM

GEOLOGICAL ANALYSIS ON THE FLUCTUATION OF RADIATION WITHIN THE TOM MAYS MINE, EL PASO, TEXAS


RICKEY, Ethan Taylor, Earth and Space Sciences Program, Bellevue College, 3000 Landerholm Circle SE, Bellevue, WA 98007

Within the Tom Mays Mine, located in the Tom Mays Unit of Franklin Mountains State Park in El Paso, Texas, is a substantial copper vein that crosses through a fault and the contact between the Red Bluff Granite (1.2 Ga) and a Basalt Dike (1.2 Ga, but after Red Bluff Granite). The origin of the copper vein is conjectural, though past studies suggest that the copper vein developed from magmatic activity that formed a nearby felsite sill, with mineralization occurring from hydrothermal solutions or heating of connate waters from intrusives. This places the age of the copper vein to around 28 Ma. The copper vein is thought to be secondary mineralization, with the quartz veins (Around 1 Ga) being primary mineralization and part of a Precambrian hydrothermal vent. Upon nearing the mine entrance, radiation was detected on a Gamma Scout at levels around 200 cpm. To further analyze the radioactivity within the mine, radiological surveys and tests were conducted. The preliminary results suggest that the radiation varied throughout the mine, but only increased where the Red Bluff Granite and the Basalt Dike was more felsic and where large veins of quartz occurred within them. This suggests that higher amounts of radiation are related to the appearance of quartz and how felsic the host igneous rock is. Furthermore, on different days of changing atmospheric pressure the radiation varied quite a bit, which may also suggest that Radon gas could be a secondary factor in the fluctuation of radiation in the mine.
Handouts
  • Geological Analysis of the Fluctuation of Radiation within the Tom Mays Mine, El Paso, Texas.pdf (916.4 kB)