| Abstract: | This report contains 10 interpretive cross sections and an integrated text describing the geology of parts of the Colorado, White River, and Death Valley regional ground-water flow systems, Nevada, Utah, and Arizona. The primary purpose of the report is to provide geologic framework data for input into a numerical ground-water model. Therefore, the stratigraphic and structural summaries are written in a hydrogeologic context.
The oldest rocks (basement) are Early Proterozoic metamorphic and intrusive crystalline rocks that are considered confining units because of their low permeability. Late Proterozoic to Lower Cambrian clastic units overlie the crystalline rocks and are also considered confining units within the regional flow systems. Above the clastic units are Middle Cambrian to Lower Permian carbonate rocks that are the primary aquifers in the flow systems. The Middle Cambrian to Lower Permian carbonate rocks are overlain by a sequence of mainly clastic rocks of late Paleozoic to Mesozoic age that are mostly considered confining units, but they may be permeable where faulted.
Tertiary volcanic and plutonic rocks are exposed in the northern and southern parts of the study area. In the Clover and Delamar Mountains, these rocks are highly deformed by north- and northwest-striking normal and strike-slip faults that are probably important conduits in transmitting ground water from the basins in the northern Colorado and White River flow systems to basins in the southern part of the flow systems.
The youngest rocks in the region are Tertiary to Quaternary basin-fill deposits. These rocks consist of middle to late Tertiary sediments consisting of limestone, conglomerate, sandstone, tuff, and gypsum, and younger Quaternary surficial units consisting of alluvium, colluvium, playa deposits, and eolian deposits. Basin-fill deposits are both aquifers and aquitards. |
| Genre: | USGS Numbered Series |
| ProdID: | 75283 |
| Citation Author: | Morin, Robert L. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | Version 1.0 |
| Citation Editor: | |
| Citation End Page: | |
| Citation Issue: | |
| Citation Keywords: | |
| Citation Language: | ENGLISH |
| Citation Larger Work Title: | |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 18 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | iii, 15 p.: ill.; maps; data files, GIS files |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | Open-File Report |
| Citation Series Code: | OFR |
| Citation Series Number: | 2006-1042 |
| Citation Search Results Text: | Gravity and magnetic data in the vicinity of Virgin Valley, southern Nevada; 2006; OFR; 2006-1042; Morin, Robert L. |
| Citation Start Page: | |
| Citation Volume: | |
| Citation Year: | 2006 |
| Type: | citation/reference |
| Text: | Gravity and magnetic data in the vicinity of Virgin Valley, southern Nevada; 2006; OFR; 2006-1042; Morin, Robert L. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/usgs_thumb.jpg |
| URL (INDEX PAGE): | http://pubs.usgs.gov/of/2006/1042/ |
| Date Other: | Tue, 7 Mar 2006 00:00 -0600 |
| Publisher: | |
