Geology of National Parks: National Park Service Support Project

Geologic Map of Lake Mead

Goals and Planned Activity

The Hamblin-Cleopatra Volcano, shown in blue by this satellite image, on the shore of Lake Mead, has been split by a fault. The N-E portion has moved almost 20km relative to the other half, due to the strike-slip motion of the Hamblin Bay fault. Click either the image or here to see a larger version.

Field mapping and digital compilation are complete for the Lake Mead (30x60-minute, 1:100,000) quadrangle. A preliminary version of the Lake Mead National Recreation Area geologic map was produced a few years ago; this task will allow updating with new mapping that was undertaken for the 1:100,000-scale map. In addition, USGS geologists will work with the Lake Mead Recreational Area Resource personnel to customize the map database to work with an Arc View interface called Geographical Information Systems (GIS) Theme Manager. The NPS Geologic Resources Division uses GIS Theme Manager to display and manipulate digital information, including geology, and is encouraging resource units at different NPS units to incorporate Theme Manager into their daily activities.

For information on mapping of sediment on the floor of Lake Mead, see USGS Open-File Report 99-581.