CURIE DEPTH ANALYSIS OF DEATH VALLEY AND SURROUNDING REGION, CALIFORNIA

Death Valley, a deep topographic basin that extends for about 200 km in a north-northwest direction in southeastern California, is a highly extended continental basin where strike-slip deformation occurs contemporaneously with crustal extension. Death Valley, a pull-apart basin, formed at a right stepping bend in the right-lateral Death Valley fault system. Seismic reflection studies have indicated a high amplitude reflector termed a bright spot in the Death Valley which is proposed to be caused by a magma body. However, the lack of heat flow data and other geophysical analyzes (e.g., magnetotellurics) cannot rule out these high amplitude reflectors being caused by other types of middle crustal fluids. We analyzed available aeromagnetic data to determine the Curie Point Depth (CPD) by spectral and inversion methods. We calculated the CDP for 0.5 degree regions using 2D spectral methods and found that the central Death Valley region had a deeper CDP (15 km) than the surrounding regions (10-13 km). Since a 0.5 degree region averages areas outside Death Valley and the results average CDPs for the region, we used 3D inversion methods to calculate a magnetic model of the Death Valley region. The 3d model indicates that the depth of the magnetic susceptible bodies decreases from 24 km in the south to 8 km in the northern part of the basin. This decrease in CPD suggests that the bright spot may be caused by magmatic material.