Joint Meeting Pacific Section, AAPG & Cordilleran Section GSA April 29–May 1, 2005, San José, California

Stream Piracy to Fan Dissection

Paul R. Troop¹ and Garry Hayes^2
1 Geology, California State Univ, Stanislaus, 3018 Romano Way, Oakdale, CA 95350, [email protected]
² Science, Modesto Junior College, 435 College Ave, Modesto, CA 95350

The Gower Gulch diversion of Furnace Creek Wash in the Black Mountains of Death Valley provides vivid examples of the effects of human intervention in a natural system. Gower Gulch, a gully that initially drained an area of 5 km2, has undergone dramatic changes as a consequence of the 1941 man-made diversion to prevent flood damage at the Furnace Creek Inn. The intended consequences of the diversion were achieved; the wash and its drainage area of 440 km2, was channeled into the gulch, thereby avoiding the Inn and shortening its route to the valley floor by 2 km. Gower Gulch provides a field laboratory where undergraduate geology students can observe an unaffected drainage (Golden Canyon), predict possible effects of the intervention, and receive immediate validation of their collaborative predictions by observing the changes that have actually taken place in the affected drainage. The diversion drastically increased the volume of flow into Gower Gulch eroding the canyon and dissecting the surface of the Gower Gulch alluvial fan. Students reported and discussed their predictions about the diversion, including flow of surface water in the wash and diversion, patterns of deposition, and changes to the alluvial fan on the valley floor. In February of 2004, I included an examination of the dissected channel in the Gower Gulch alluvial fan into the exercise. In February of 2005 students from Modesto Junior College (MJC) and California State University Stanislaus (CSUS) will participate in this exercise and compare their data with the 2004 data. This exercise has the dual objectives of introducing students to field research and initiating a longitudinal study to assess the yearly effects of erosion on the Gower Gulch fan dissection.

Posted with permission of The Geological Society of America; abstract also online (http://gsa.confex.com/gsa/2005CD/finalprogram/abstract_85286.htm). © Copyright 2005 The Geological Society of America (GSA).