Washington State comprises one of the most geologically active regions in North America. A series of exotic terranes have plowed into one another to form the bulk of the state. The Juan de Fuca tectonic plate is diving beneath Washington from its western margin, generating earthquakes and pushing up the Olympics and Cascades. Lava, repeatedly oozed out from enormous fissures, has built up basalt deposits nearly two kilometers deep. Volcanoes in the Cascades intermittently erupt and spew gritty ash over vast areas. Continental glaciers have edged their way into the state from the north multiple times and created a set of unmistakable landforms and deposits. A series of enormous floods repeatedly have swept over the eastern part of the state creating the channeled scablands. Protection Island, where we study the biology of seabirds, preserves a thin but magnificent slice of the Pleistocene component of this history – one of the finest in the state. In collaboration with two geologists, we are producing the first detailed description and interpretation of this spectacular series of deposits. This talk will feature an overview of Washington’s geologic past, followed by a description and preliminary analysis of the interval of history revealed by Protection Island’s strata.
Available at: http://works.bepress.com/shandelle_henson/33/