Field Trip to Eastern California and Nevada
ERTH 4003/4807
24 April - 6 May, 2015
Every year, the department offers a fourth-year field trip under the course code ERTH 4807 Field Geology II. This year, the students were lucky enough to explore eastern California and Nevada, under the tutelage of Professors Brian Cousens and Nadine Wittig. There is no better place to take students to see great field geology! In California, they spent two days each in Death Valley and the Long Valley Caldera region. In Nevada, they studied the Carson Sink, Battle Mountain, and Fish Creek Mountain areas first-hand.
The objective of the trip was to investigate youthful, well-exposed volcanism, tectonism, mineral deposits, and geothermal energy systems in the southwestern United States. The course was held in the Great Basin, a region of late Cenozoic lithospheric extension, due to the interaction of the North American and Farallon (Juan de Fuca) plates. Volcanic activity now exposed in the Great Basin largely pre-dates extension, and is associated with low-angle subduction of the Farallon plate, followed by steepening of the Farallon slab and rollback of the subduction zone to the west. Subsequent Great Basin extension has formed normal faults and horst and graben structures, where the horsts are tilted fault blocks. These structural features allow groundwater to descend, become heated, and return to the surface to form geothermal fields. The same geothermal waters dissolve metals from the surrounding rocks and have then formed some of the most prolific silver and gold mines in North America.
Students were expected to submit an essay on a selected topic prior to departure. Once arrived, they honed their ability to record scientific data in the field, in the form of a field notebook. These notebooks contain observations and sketches. The students learn to draw conclusions as to geological processes from their observations.
The trip culminated in each student giving a short presentation in the field on a selected topic in southwestern US geology.