Dennis Feeney – State Geologist from the Idaho Geological Survey

Photo depicting Geologic mapping in the Weiser embayment; Idaho’s full-suite volcanic field in Columbia River Basalt province

Title: Geologic mapping in the Weiser embayment; Idaho’s full-suite volcanic field in Columbia River Basalt province
Abstract: Spurred on by oil and gas interests in the Payette Basin, in 2012 Idaho Geological Survey began geologic mapping at 1:24,000-scale in the Weiser/Boise area of southwest Idaho. Eight years on and fourteen 7.5’ quadrangles completed, and the volcanic and tectonic story continues to evolve from James Fitzgerald’s (PhD UI, 1981) original interpretation. Using modern analytical methods like XRF, microprobe, paleomagnetics, U-Pb zircon and 40Ar/39Ar dating, and LiDAR, in conjunction with traditional thin-section petrography and boots on the ground we’ve been able to reconfigure the basic unit formations of the Weiser volcanics, a regional full-suite volcanic field within the Columbia River Basalt province, and add much needed clarity to the timing of events within the Weiser embayment as a whole. 

Where: RUCH 103
When: Monday, October 14th
Time: 3:00pm
Directions: Map