NS43B-1972
High-Resolution Ground-Based Magnetic Survey of a Buried Volcano: Anomaly B, Amargosa Desert, NV

Thursday, 17 December 2015
Poster Hall (Moscone South)
Ophelia George1, Judy McIlrath2, Alexandra Kathryn Farrell1, Elisabeth Gallant3, Samantha Tavarez1, Christine M Downs1, Mary Wambui Njoroge1, James Adams Wilson1, Charles Connor1, Laura Connor4 and Sarah Kruse1, (1)University of South Florida Tampa, Tampa, FL, United States, (2)Univ South Florida, Tampa, FL, United States, (3)University of South Florida Tampa, Geology, Tampa, FL, United States, (4)University of South Florida, Tampa, FL, United States
Abstract:
Aeromagnetic surveys over the Amargosa Desert, Nevada, have revealed the presence of several magnetic anomalies that have been interpreted to be caused by buried volcanoes; many of these anomalies have been confirmed by drilling. We present data collected from a high-resolution, ground-based magnetic survey over Anomaly B, the largest of these anomalies, that reveal details about a buried crater and its associated lava flow, not previously observed in the aeromagnetic surveys. These details provide insight into the nature of the eruption and the volume of this buried volcano. Results from non-linear inversion demarcate a crater with a diameter of approximately 700 m and a base approximately 150 m below the ground surface. Coupled with well log data, the inversion results suggest a total volume for the Anomaly B crater area and associated lava flows of approximately 1.0 ± 0.4 km3, based on an estimated lava flow field area of 24 km2 and a lava thickness of 42 ± 15 m.