Radiometric Dating of the Danskin Hills Rhyolites in Order to Constrain Geologic Activity Throughout the Western Snake River Plain
Dr. Mark Schmitz
Radiometric dating of rock units along the edges of the eastern and western Snake River Plain help to place age constraints on geologic events that have occurred in the region. The Miocene rhyolites of the Mount Bennett Hills have previously been dated to correlate information regarding the movement of the Yellowstone Hot Spot and the extension and subsidence of the western Snake river plain. The area of the interest here is the Danskin Hills Formation located on the western edge of the Mount Bennett Hills Formation. Geochronology for the Danskin Mountains Rhyolites has previously been reported using K-Ar and Ar-Ar ages and places the formation of the rhyolites from 10.2+/- 0.3 Ma to 9.2 +/- 0.13 Ma (Clemens and Wood, 1993). This report will use new high-precision U-Pb zircon ages for several rhyolites to place tighter constraints on the timing and tempo of these voluminous eruptions. More precise ages will help to define tectonic events that have occurred on the Western Snake River Plain as well as providing more insight to our understanding of the history of the Yellowstone Hotspot.