Rocky Mountain Section - 68th Annual Meeting - 2016

Paper No. 30-9
Presentation Time: 8:00 AM-5:00 PM

PRELIMNARY MAPPING AND STRUCTURAL INTERPRETATION OF AN AUREOLE IN EASTERN WASHINGTON


GOODSON, Bernt, ARMSTRONG, Austin and PRITCHARD, Chad J., Department of Geology, Eastern Washington University, 130 Science Building, Cheney, WA 99004-2439, bernt.goodson@eagles.ewu.edu

Bedding and foliation at Willow Lake in Eastern Washington generally dips to the east, which is very different than primary features associated with the Cordilleran. To determine more of the structural significance of the area a preliminary geologic map was produced using Google Earth. This project identifies the source for eastward dipping strata as magmatic intrusions. Geologic structures range from small-scale flow folds in the contact metamorphic aureole, small scale faults, flexural slip, localized folds associated with emplacement of mafic-dikes, and tilted bed associated with emplacement of a larger granitic pluton(s). Plutonism likely occurred during the Cretaceous and Eocene periods. The creation of the preliminary map begins to show the complexity of contact metamorphism, assimilation, and partial melting processes in the context of regional geology and magmatic emplacement.