Victoria Langenheim

This report summarizes the acquisition, data processing, and preliminary interpretation of a high-resolution aeromagnetic and radiometric survey near the confluence of the Big and Little Chino basins in the headwaters of the Verde River, Arizona. The goal of the aeromagnetic study is to improve understanding of the geologic framework as it affects groundwater flow, particularly in...

A high-resolution aeromagnetic survey of the Amargosa Desert and surrounding areas provides insights into the buried geology of this structurally complex region. The survey covers an area of approximately 7,700 km2 (2,970 mi2), extending from Beatty, Nevada, to south of Shoshone, California, and includes parts of the Nevada Test Site and Death Valley National Park. Aeromagnetic flight...

Gravity and aeromagnetic data provide insights into the subsurface lithology and structure of the Virgin River Depression (VRD) of Nevada, Utah, and Arizona. The gravity data indicate that the Quaternary and Tertiary sedimentary deposits hide a complex pre-Cenozoic surface. A north-northwest-trending basement ridge separates the Mesquite and Mormon basins, as evidenced by seismic...

This report summarizes geophysical investigations in the Amargosa Desert and surrounding areas conducted between 1997 and 2000 in support of the Death Valley Regional Water-Flow Modeling Project of the U.S. Geological Survey. These investigations used both gravity and aeromagnetic data to develop a regional-scale tectonic and lithologic model for the near-surface. Gravity data were...

The basin-basement contact for Yucca Flat was modeled using isostatic gravity data, a linear density-depth function for the basin deposits, and drill-hole constraints to produce a digital database of both the depth to basement and the gravitational anomaly associated with the basement rocks. The model predicts a depth of roughly 2,500 m in the deepest, southern part of the basin. The...

The contrast in density between basin-filling deposits and underlying basement rocks in the Basin and Range province produces a distinctive pattern of gravity anomalies that roughly correlates with basin-and-range topography. This is especially apparent in the Death Valley extended terrane, where minima in residual gravity closely correspond to well-known extensional basins, such as...