Investigation of Linear Magnetic Anomalies in the Funeral Mountains, Death Valley Region, California
Hillhouse JW and Morin R. 2004. Investigation of Linear Magnetic Anomalies in the Funeral Mountains, Death Valley Region, California. Open-File Report 03-12
A series of northeast-trending magnetic anomalies were detected in the Funeral Mountains with a high-resolution aeromagnetic survey of the Death Valley-Amargosa Desert region of California and Nevada. We report results of a ground-level magnetic survey that ties the anomalies to strongly magnetic beds within the Stirling Quartzite. The study area covers 18 km2 near Indian Pass, approximately 30 km south of Beatty, Nevada. Member A of the Stirling Quartzite contains magnetite-rich schist, characterized by magnetic susceptibility of 0.015 (SI). The magnetic beds, which are concentrated in a 37-m thick interval, crop out in three ridges separated by sub-parallel normal faults. Two-dimensional modeling of the magnetic profile over one of the ridges fits an east-dipping layer, consistent with the local geologic structure. In the Death Valley region, spring alignments and magnetic anomalies appear to be related. Although we found no evidence in the Funeral Mountains that the fault zones are unusually magnetic, the normal faults produce lengthy tilted blocks that do produce magnetic anomalies from upturned magnetic beds within the blocks. In this way, patterns of spring occurrence and linear aeromagnetic anomalies may both reflect the regional geologic structure.