Three-dimensional hydrogeologic framework for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

This dataset was created in support of a study focusing on groundwater resources in the Great Basin 
carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a complex aquifer system comprised 
of both unconsolidated and bedrock formations covering an area of approximately 110,000 square miles. 
The aquifer system is situated in the eastern portion of the Great Basin Province of the western United 
States. The eastern Great Basin is experiencing rapid population growth and has some of the highest 
per capita water use in the Nation. These factors, combined with the arid setting, have levied intensive 
demand upon current groundwater resources and, thus, predictions of future shortages. Because of the 
large regional extent of the aquifer system, rapid growth in the region, and the reliance upon groundwater 
for urban populations, agriculture, and native habitats, the GBCAAS was selected by the U.S. Geological 
Survey (USGS) Water Resources program as part of the National Water Census Initiative to evaluate the 
Nation's groundwater availability.
		
The complex stratigraphic and structural framework of the GBCAAS region controls groundwater flow 
throughout the region. A three-dimensional (3D) hydrogeologic framework was constructed to represent 
the hydrogeologic units and major structures in the region to aid in the development of both the conceptual 
and numerical groundwater-flow models of the study area. The 3D hydrogeologic framework was constructed 
by extracting and combining information from digital elevation models, geologic maps, borehole lithologic 
logs, geologic cross sections, and digital geophysical models.
		
This dataset is composed of nine raster layers:
		
1. ubfau_top - Altitude of the top of the upper basin-fill aquifer unit in meters above North American vertical datum of 1988.
			
2. lbfau_top - Altitude of the top of the lower basin-fill aquifer unit in meters above North American vertical datum of 1988.
		
3. vu_top - Altitude of the top of the volcanic unit in meters above North American vertical datum of 1988.
		
4. ucau_top - Altitude of the top of the upper carbonate aquifer unit in meters above North American vertical datum of 1988.
		
5. uscu_top - Altitude of the top of the upper siliciclastic confining unit in meters above North American vertical datum of 1988.
		
6. tlcau_top - Altitude of the top of the thrusted lower carbonate aquifer unit in meters above North American vertical datum of 1988.
		
7. lcau_top - Altitude of the top of the lower carbonate aquifer unit in meters above North American vertical datum of 1988.
		
8. tnccu_top - Altitude of the top of the thrusted noncarbonate confining unit in meters above North American vertical datum of 1988.
		
9. nccu_top - Altitude of the top of the noncarbonate confining unit in meters above North American vertical datum of 1988.

Tags: bedrock-lithology, california, geologic-units, geology, geoscientificinformation, great-basin, idaho, igneous-rocks, inlandwaters, metamorphic-rocks, nevada, sedimentary-rocks, usgs-66dd6f14-fb2b-4651-890c-d111e76b3157, utah
Organization: Department of the Interior