Geologic Reconnaissance of Parts of the Walla Walla and Pullman, Washington, and Pendleton, Oregon 1 deg x 2 deg AMS Quadrangles

摘要

This investigation was conducted to determine the location and continuity of faulting, the tectonic framework and the evidence for contemporary tectonic activity centering around the Hite Fault System, Wallula Fault system and Service Anticline in portions of southeast Washington and north central Oregon near six U.S. Army Corps of Engineers' dams: Lower Granite, Little Goose, Lower Monumental, Ice Harbor, McNary and Mill Creek. The study includes a review of previous geologic mapping and lineament studies, a review and analysis of regional tectonics and reconnaissance geological mapping. The areas investigated are shown on Figure 1 and include: (1) a corridor along the lower Snake River; (2) a strip along the Hite Fault in the northwest flank of the Blue Mountains; (3) the Kooskooskie - Mill Creek area east of Walla Walla and (4) the Service Anticline. The study areas include parts of the gently west-dripping Palouse slope, and northwest flank of the Blue Mountains Anticlinorium, the Dalles-Umatilla Syncline, and the Pasco and Walla Walla structural basins.