nrg_irg_inv - Digital raster grid of the depth to pre-Cenozoic basement for the Northern Rocky Mountains and adjacent areas, Idaho, Montana, Washington, Oregon, and Wyoming.

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Mankinen, E.A.

Originator: Hildenbrand, T.G.

Originator: Zientek, M.L.

Originator: Box, S.E.

Originator: Bookstrom, A.A.

Originator: Carlson, M.H.

Originator: Larsen, J.C.

Publication_Date: 2004

Title:

nrg_irg_inv - Digital raster grid of the depth to pre-Cenozoic basement for the Northern Rocky Mountains and adjacent areas, Idaho, Montana, Washington, Oregon, and Wyoming.

Edition: version 1.0

Geospatial_Data_Presentation_Form: raster digital data

Series_Information:

Series_Name: Open-File Report

Issue_Identification: 1413

Publication_Information:

Publication_Place: Menlo Park, California

Publisher: U.S. Geological Survey

Online_Linkage: <http:/pubs.usgs.gov/of/2004/1413/>

Description:

Abstract:

Regional gravity surveys measure the attraction of gravity at the Earth’s surface. The magnitude of the gravity field at a single station, however, is influenced by a number of factors which must be predicted and compensated (e.g., mass, rotation and ellipsoidal shape of the Earth; elevation of the gravity station; attraction of nearby topography or bathymetric relief). By applying well-established corrections to all stations within a survey, gravity maps and their derivatives can be used tocharacterize local density variations primarily in the middle and upper crust. The raster grid, nrg_irg_inv, represents a qualitative estimate of depth to pre-Cenozoic basement in the study area. Depths determined for this region have not been constrained by drill-hole information.

Purpose:

This raster grid was created to assist in developing regional digital earth science data and interpretations that can be used by Federal land managers in regional planning and special assessments such as road-less area withdrawals.

Supplemental_Information:

The depth to pre-Cenozoic basement grid is provided in three formats; ESRI gird, Geosoft OASIS montaj format and binary format used by the USGS. This metadata file describes the processes used to create the ESRI grid and does not provide additional information about the Geosoft or USGS grids. The GeoSoft OASIS montaj format grid is available in the \GeoSoft folder at the top-level directory. The binary USGS format grid is available in the \USGS folder at the top-level directory.

Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2004

Currentness_Reference: publication date

Status:

Progress: Complete

Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -117.625401

East_Bounding_Coordinate: -109.241796

North_Bounding_Coordinate: 49.132840

South_Bounding_Coordinate: 41.860885

Keywords:

Theme:

Theme_Keyword: geophysics

Theme_Keyword: gravity map

Theme_Keyword: isostatic residual gravity

Theme_Keyword: gravity inversion

Place:

Place_Keyword: Northern Rocky Mountains

Place_Keyword: Idaho

Place_Keyword: Montana

Place_Keyword: Washington

Place_Keyword: Oregon

Place_Keyword: Wyoming

Place_Keyword: USA

Access_Constraints: none

Use_Constraints: none

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Edward A. Mankinen

Contact_Organization: U.S. Geological Survey

Contact_Position: Geologist

Contact_Address:

Address: 345 Middlefield Rd, Mail Stop 937

City: Menlo Park

State_or_Province: CA

Postal_Code: 94025-3591

Contact_Voice_Telephone: (650) 329-4669

Contact_Facsimile_Telephone: (650) 329-4664

Contact_Electronic_Mail_Address: emank@usgs.gov

Native_Data_Set_Environment:

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722

Data_Quality_Information:

Attribute_Accuracy:

Logical_Consistency_Report: No duplicate features exist

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Accuracy is dependent upon the individual making the observation and the reliability of the station location, especially elevation. Dataset for the study area was developed over a number of years by many individuals and, thus, the quality may be highly variable. For regional surveys such as this, anomaly values generally are accurate to within 2 mGal (Simpson and Jachens, 1989).

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

Depth to basement is sensitive to the density-depth function used and it is difficult to judge the exact error, but deep basins might be as much as 50 percent shallower than shown on the map

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: Jachens, R.C.

Publication_Date: unpublished data

Type_of_Source_Media: online

Source_Time_Period_of_Content:

Source_Currentness_Reference: ground condition

Source_Citation_Abbreviation: Jachens (unpub. data, 1995)

Source_Contribution: This is the source of the depth to pre-Cenozoic basement data

Source_Information:

Source_Citation:

Citation_Information:

Originator: Jachens, R.C.

Originator: Moring, B.C.

Publication_Date: 1990

Title:

Maps of the thickness of Cenozoic deposits and the isostatic residual gravity over basement for Nevada

Series_Information:

Series_Name: Open-File Report

Issue_Identification: 90-404

Publication_Information:

Publisher: U.S. Geological Survey

Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 1990

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: Jachens and Moring (1990)

Source_Contribution: provided the method of determining the basement depth

Process_Step:

Process_Description:

These data were extracted from a grid of pre-Cenozoic basin depths for the western United States (R.C. Jachens, unpublished compilation, 1995), and re-projected to the specifications of the study area using USGS in-house developed software. In-house software was used to convert from USGS grid format to ARC/INFO grid format. Basin depths were determined using the gravity inversion technique of Jachens and Moring (1990).

Source_Used_Citation_Abbreviation: Jachens (unpublished, 1995)

Source_Used_Citation_Abbreviation: Jachens and Moring (1990)

Process_Date: 2003

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Grid Cell

Row_Count: 799

Column_Count: 613

Vertical_Count: 1

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: Albers Conical Equal Area

Albers_Conical_Equal_Area:

Standard_Parallel: 44.000000

Standard_Parallel: 48.000000

Longitude_of_Central_Meridian: -114.000000

Latitude_of_Projection_Origin: 41.000000

False_Easting: 0.000000

False_Northing: 0.000000

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: row and column

Coordinate_Representation:

Abscissa_Resolution: 1000.000000

Ordinate_Resolution: 1000.000000

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1927

Ellipsoid_Name: Clarke 1866

Semi-major_Axis: 6378206.400000

Denominator_of_Flattening_Ratio: 294.978698

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey Information Services

Contact_Address:

Address_Type: mailing address

Address: P.O. Box 25286

City: Denver

State_or_Province: CO

Postal_Code: 80225

Country: USA

Contact_Voice_Telephone: (888) ASK-USGS

Contact_Voice_Telephone: (888) 275-8747

Contact_Electronic_Mail_Address: infoservices@usgs.gov

Resource_Description: Downloadable data for USGS Open-File Report 2004-1413

Distribution_Liability:

The U.S. Geological Survey (USGS) provides these geographic data "as is". The USGS makes no guarantee or warranty concerning the accuracy of information contained in the geographic data. The USGS further makes no warranties, either expressed or implied as to any other matter whatsoever, including, without limitation, the condition of the product, or its fitness for any particular purpose. The burden for determining fitness for use lies entirely with the user. Although these data have been processed successfully on computers at the USGS, no warranty, expressed or implied, is made by the USGS regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty. In no event shall the USGS have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including, but not limited to, any loss of profits arising out of use of or reliance on the geographic data or arising out of the delivery, installation, operation, or support by USGS.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: ZIP

Format_Version_Number: 9.0

Format_Specification: WINZIP® 9.0

Format_Information_Content:

ZIP archive for thirteen ArcInfo® grids: nr_bouguer, nrg_irg, nrg_irg_1vd, nrg_irg_inv, nrg_irg_iw, nrg_irg_lw, nrg_irg_tr, nrm_aeromag, nrm_magres, nrm_mpot, nrm_mpot_iw, nrm_mpot_lw, and nrm_mpot_tr.

File_Decompression_Technique:

To open a ZIP archive, double-click on the archive listed in My Computer or Windows Explorer, drag and drop the archive onto WINZIP®, or use the standard Open dialogue box.

Transfer_Size: 26 (MB)

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name: <http://pubs.usgs.gov/of/2004/1413>

Fees: No fee for downloadable data and report

Technical_Prerequisites:

User must have geographic information system (GIS) software capable of reading ESRI ArcInfo® file formats.

Metadata_Reference_Information:

Metadata_Date: 20050929

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Jeremy C. Larsen

Contact_Organization:

Information Systems Support (under contract to the U.S. Geological Survey)

Contact_Position: contractor

Contact_Address:

Address_Type: mailing and physical address

Address: 904 W. Riverside Ave, Room 202

City: Spokane

State_or_Province: WA

Postal_Code: 99201

Contact_Voice_Telephone: (509) 368-3118

Contact_Electronic_Mail_Address: jlarsen@usgs.gov

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

Metadata_Extensions:

Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>

Profile_Name: ESRI Metadata Profile