Principal Facts for Gravity Stations and Physical Property Measurements in the Lake Mead 30' by 60' quadrangle, Nevada and Arizona
by V.E. Langenheim1, J.G. Davidson1, M.L. Anderson1, and H.R. Blank, Jr.2
U.S. Geological Survey Open-File Report OF 99-435
Version 1.0
1999
U.S. DEPARTMENT OF THE INTERIOR
BRUCE BABBITT, Secretary
U.S. GEOLOGICAL SURVEY
Charles G. Groat, Director
This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey (USGS) editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
1 345 Middlefield Road, Menlo Park, CA 94025
2 W 904 Riverside Avenue, Spokane, WA 99201
INTRODUCTION
The U.S. Geological Survey (USGS) collected 811 gravity stations on the Lake Mead 30� by 60� quadrangle from October, 1997 to September, 1999. These data were collected in support of geologic mapping of the Lake Mead quadrangle. In addition to these new data, gravity stations were compiled from a number of sources (Table 1 in PDF of report, below). These stations were reprocessed according to the reduction method described below and used for the new data. Density and magnetic susceptibility measurements were also performed on more than 250 rock samples.
The Lake Mead quadrangle ranges from 360 to 360 30� north latitude and from 114° to 115° west longitude. It spans most of Lake Mead (see index map, below), the largest manmade lake in the United States, and includes most of the Lake Mead National Recreation Area. Its geology is very complex; Mesozoic thrust faults are exposed in the Muddy Mountains, Precambrian crystalline basement rocks are exhumed in tilted fault blocks near Gold Butte, extensive Tertiary volcanism is evident in the Black Mountains, and strike-slip faults of the right-lateral Las Vegas Valley shear zone and the left-lateral Lake Mead fault system meet near the Gale Hills. These gravity data and physical property measurements will aid in the 3-dimensional characterization of structure and stratigraphy in the quadrangle as part of the Las Vegas Urban Corridor mapping project.
Index map
View this report as a PDF
This report consists of 15 pages with eight figures and two tables. The report is provided as a PDF file for which you will need Adobe Acrobat Reader to view. You can download a copy of the latest version (4.0 at the time of this publication) by clicking the button above.
To view the PDF file (of99-435.pdf), CLICK HERE (12.6 MB).
View the version history
CLICK HERE view the version-history file for this report.
Data
CLICK HERE view the metadata in text format (lm-meta-of99-435.txt; 7 KB).
CLICK HERE view the readme file for the metadata (lm_readme.txt; 6 KB).
CLICK HERE view the physical property data (lm.prop; 19 KB).
CLICK HERE view the gravity data (lm_100k.iso; 159 KB).
Notes on downloading files instead of viewing them
To force your browser to download files, hover the pointer over the hyperlink and do the following:
Macintosh: hold the mouse button down for a moment to display a pop-up menu and select "Save this link as..." (Netscape Navigator) or "Download Link to Disk" (Internet Explorer) and navigate to where you want the file saved.
Windows machines: use the right mouse button to display a pop-up menu and select "Save Link As..." (Netscape Navigator) or "Save Target As..." (Internet Explorer) and navigate to where you want the file saved.
To contact the senior author, email Victoria Langenheim (zulanger@mojave.wr.usgs.gov).
The URL of this page is http://geopubs.wr.usgs.gov/open-file/of99-435/index.html
Date created: 10/14/1999
Last modified: 10/14/1999
Email technical-support comments to
Mike Diggles (mdiggles@mojave.wr.usgs.gov).