Craig dePolo Honored with GSA Fellowship
“Society Fellowship is an honor bestowed on the best of our profession by election at the spring GSA Council meeting.”
Craig M. dePolo (Nevada Bureau Mines & Geology): Dr. dePolo is widely recognized by his peers in the areas of neotectonics, paleoseismology, and earthquake preparedness. He has published numerous reports and maps at the NBMG and in peer-reviewed journals. Dr. dePolo has been a driving force for earthquake preparedness in Nevada for more than 30 years. —William Lund
“As part of Geologic Map Day (October 18, 2019) and Earth Science Week (October 13-19, 2019, the U.S. Geological Survey invited university-level students to enter its 2019 Best Student Geologic Map Competition. The contest will be judged at the Geological Society of America’s Annual Meeting in Phoenix, Arizona, September 22-25, 2019.
The U.S. Geological Survey, in collaboration with AGI, GSA, GSA Foundation, Association of American State Geologists, American Institute of Professional Geologists, and the Journal of Maps, is proud to be hosting the 7th annual Best Student Geologic Map Competition at the GSA Annual Meeting in Phoenix, Arizona. The competition will highlight student research from around the world that utilizes field mapping and the creation of geologic maps as a major component.”
Discovery and Analysis of a Blind Geothermal System in Southeastern Gabbs Valley, Western Nevada
CRAIG, Jason W., Nevada Bureau of Mines and Geology, University of Nevada, Reno, NV 89557
GSA Annual Meeting in Phoenix, Arizona, USA – 2019; Paper No. 94-2
This study assessed the potential for high-temperature (≥130°C) blind geothermal systems in southeastern Gabbs Valley, Nevada, an area with no previously known geothermal activity or geothermal exploration, by integration of geologic, geophysical, and geochemical datasets. Gabbs Valley is a complex, tectonically active basin within the Great Basin on the boundary between the transtensional central Walker Lane domain and extensional Basin and Range province. The termination of the Petrified Springs fault, a major dextral fault of the central Walker Lane, into an array of normal faults indicates that the area occupies a displacement transfer zone, which is a favorable structural setting for geothermal activity. A substantial northwest-trending gravity high within the south-central part of the basin is produced from offsets along concealed northwest-striking dextral-normal faults that intersect strands of north-northeast-striking normal faults. Multiple lines of direct and indirect evidence suggest the presence of a blind geothermal system in this area, including collocated intersecting gravity gradients, magnetic-low, low-resistivity, and 2-m temperature anomaly. Potentially related, warm (32°C) water samples from agricultural wells 7 km northwest of the 2-m temperature anomaly yield geothermometers indicating subsurface fluid temperatures of 130-140°C. Six temperature-gradient holes were drilled to target the extent of the shallow-temperature and geophysical anomalies. Two wells contained high temperatures exceeding boiling with bottom-hole temperatures of 114.5°C and 124.9°C, and the remaining wells displayed elevated to background temperatures ranging from 79.2°C to 28.7°C. The observed temperature gradients for the two hottest drill holes necessitate intercepts of hydrothermal fluids and establish the discovery of a blind geothermal system that may be capable of supporting a power plant.
Congratulations to Craig and Jason!