Hydrostructural Maps of the Death Valley Regional Flow System, Nevada and California

The faults shown on maps A (Structural Framework, Neogene Basins, and Potentiometric Surface) and B (Structural Framework, Earthquake Epicenters, and Potential Zones of Enhanced Hydraulic Conductivity) are largely from Workman and others (in press), and fit one or more of the following criteria: (1) faults that are more than 10 km in map length; (2) faults with more than 500 m of displacement; and (3) faults in sets that define a significant structural fabric that characterizes a particular domain of the DVRFS.

The following fault types are shown: Neogene normal, Neogene strike-slip, Neogene low-angle normal, pre-Tertiary thrust, and structural boundaries of Miocene calderas. We have highlighted faults that have late Pleistocene to Holocene displacement (Piety, 1996). Areas of thick Neogene basin-fill deposits (thicknesses 1-2 km, 2-3 km, and >3 km) are shown on map A, based on gravity anomalies and depth-to-basement modeling by Blakely and others (1999).

We have interpreted the positions of faults in the subsurface, generally following the interpretations of Blakely and others (1999). Where geophysical constraints are not present, the faults beneath late Tertiary and Quaternary cover have been extended based on geologic reasoning. Nearly all of these concealed faults are shown with continuous solid lines on maps A and B, in order to provide continuous structures for incorporation into the hydrogeologic framework model (HFM).

Map A also shows the potentiometric surface, regional springs (25-35 degrees Celsius, D'Agnese and others, 1997), and cold springs (Turner and others, 1996). A composite base map is included based upon published 83-m DEM data from USGS 1:250,000-scale quadrangles, as well as road lines and political boundaries from published USGS 1:100,000-scale DLG data. The 1:100,000-scale data were generalized to 1:250,000 scale for inclusion with the 1:250,000-scale database.

Additional coverages include a ground-water model area coverage, and text labels for structural features. Files necessary for printing the map are also included such as text fonts, linesets, shadesets, projection files, and AML files. These files are all explained in the included README.txt file.