2021 Cordilleran Section Meeting

Sarah Trevino, University of Wisconsin–Madison, sfshields@wisc.edu; Nick van Buer, California State Polytechnic Pomona, vanbuer@gmail.com; Basil Tikoff, University of Wisconsin–Madison, basil@geology.wisc.edu; Sandra Wyld, MapTect, swyld2@gmail.com.

Description: One day. This field trip will investigate emplacement mechanisms and deformation of several large Cretaceous arc granites in northwestern Nevada (Sahwave, Nightingale, Fox, Granite, and Selenite Ranges). The trip will emphasize age, size, and composition of plutons, new fabric studies, evidence for dextral shearing during emplacement, and regional tectonics.

John Louie, University of Nevada, Reno, louie@unr.edu. Philipp Ruprecht, Department of Geological Sciences and Engineering, University of Nevada, Reno.

Description: One hour. This is a virtual tour that will include time-lapse video to compress an eight-hour tour of intersecting geologic and human history into a one-hour experience. A phreatic blast megatons in size created a mile-wide crater, now filled by Soda Lake. The magnitude-7 Dixie Valley earthquake ripped along more than 60 km of the Stillwater Range–front in 1954. The 12 kiloton Shoal nuclear test in 1963 created a 50-meter-wide cavity in solid granite.

Sponsored By Merrily Graham

Warren J. Nokleberg, U.S. Geological Survey, wnokleberg@usgs.gov; Russell W. Graymer, U.S. Geological Survey, rgraymer@usgs.gov.

Description: Virtual trip, two to four hours. Employing both newly compiled geologic and geophysical maps and Google Maps, this trip will present geologic field, age, and geophysical data and interpretations for sites along California Highways 140 and 120, from the western Sierra Nevada foothills, through Yosemite Park, over Tioga Pass, and into Mono Basin.

Louise D. Hose, University of Nevada, Reno, hose@drkarst.net; Gretchen Baker, National Park Service, Great Basin National Park, Gretchen_Baker@nps.gov.

Description: Virtual trip, one half day. The organizers will use video and slides to visit well-studied active and relict carbonate caves formed by hypogenic, often sulfide-rich waters in Mexico, Italy, and the Guadalupe Mountains. The second part will visit Nevada (and western Utah) caves to demonstrate the evidence for ancient, hypogenic speleogenesis in the Great Basin.

Barbara EchoHawk, Metropolitan State University of Denver, echohwk@msudenver.edu; Uwe R. Kackstaetter, Metropolitan State University of Denver, kackstae@msudenver.edu.

Description: Half-day. Join us on a virtual field trip along northern Colorado’s Front Range, where we will dig into a handful of our most compelling geologic stories, at regional to microscopic scales. The virtual trip will expand on a few stops from our field trip during the 2016 GSA Annual Meeting (“Roadside faults, folds, fossils, crystals, and diamond pipes”: See our field guide at https://doi.org/10.1130/2016.0044(11)) and will introduce new sites.
The geographic extent of the field trip is along the Front Range from north of Boulder to south of the Wyoming state line. Within that range, approximately 5 stops will be featured with virtual coverage.

Ned Sterne, independent geologist, nedsterne@aol.com; Bob Raynolds, Denver Museum of Nature & Science, bobraynolds1@gmail.com; Jim Granath, consulting structural geologist, jwgranath@q.com.

Description: Half-day. This will be a virtual trip exploring data and techniques used to inform the Interstate 70 transect. Magnetotellurics, low-temperature thermochronology, seismic, wells, outcrop, and strike analogs constrain the interpretation of Ancestral Rockies, Laramide, and post-Laramide deformation. Palinspastic restoration reveals ~80 kilometers of horizontal translation across the basement uplifts of central Colorado.