Identification_Information: Citation: Citation_Information: Originator: R.C. Jachens Originator: V.E. Langenheim Publication_Date: 2014 Title: Gravity survey and depth to basement of Fort Irwin Military Reservation, Mojave Desert, California Geospatial_Data_Presentation_Form: point digital data Series_Information: Series_Name: Open-File Report Issue_Identification: 2013–1024–H Publication_Information: Publication_Place: Menlo Park, CA Publisher: U.S. Geological Survey Online Linkage: http/pubs.usgs.gov/ofr/2013/1024/h/ Description: Abstract: Isostatic gravity grid, depth to basement grid, and gravity data for the Fort Irwin Military Reservation, Mojave Desert, California. Gravity data were compiled, collected, and edited to produce an isostatic gravity map. Digital Files: The database includes an ASCII file containing gravity data and two ASCII files containing grid intersection values and locations for the Isostatic Residual gravity, and a depth to basement grid derived from the gravity data. This metadata file describes the gravity data named iso.txt. Purpose: Gravity map identifies gravity anomalies as a basis for geophysical interpretations. Supplemental_Information: This database updates geophysical information originally presented in smaller-scale formats. Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -117.3 East_Bounding_Coordinate: -116.2 North_Bounding_Coordinate: 35.9 South_Bounding_Coordinate: 34.7 Keywords: Theme: Theme_Keyword: isostatic gravity Theme_Keyword: gravity anomaly Place: Place_Keyword: Southern California Place_Keyword: Mojave Desert Place_Keyword: Fort Irwin Military Reservation Access_Constraints: none Use_Constraints: Uses of this digital data should not violate the spatial or attribute resolution of the data. Although the digital form of the data stores location and attribute values to several decimals of precision, the data are subject to the accuracy and precision inherent in the data due to data collection and processing limitations. Where these data are used in combination with other data, the precision and accuracy of the resulting dataset is limited by the precision and accuracy of the input datasets. Acknowledgement of the U.S. Geological Survey is appreciated for products derived from these data. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Robert C. Jachens Contact_Organization: U.S. Geological Survey Contact_Position: geophysicist Contact_Address: Address_Type: physical address Address: 345 Middlefield Rd. City: Menlo Park State_or_Province: CA Postal_Code: 94025 Country: USA Contact_Voice_Telephone: 650-329-5300 Contact_Electronic_Mail_Address: jachens@usgs.gov Native_Data_Set_Environment: ASCII Native_Data_Set_Environment: data was stored and analysed on a SUN Ultra4000 UNIX platform Geospatial_Data_Presentation_Form: ascii digital data (gravity data) Series_Information: Series_Name: U.S. Geological Survey (USGS) Open-File Report Issue_Identification: XXXX Publication_Information: Publication_Place: Menlo Park, California Publisher: U.S. Geological Survey Online_Linkage: Data_Quality_Information: Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Accuracy of the point data is roughly 40 m, as well as the data can be located on a 1:24,000-scale topographic map Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Accuracy of the point data vary; most of the elevations are accurate to 10 feet or less. In some of the more mountainous areas, the accuracy may fall to 20 to 40 feet. Attribute_Accuracy: Attribute_Accuracy_Report: Observed gravity data are accurate to 0.05 mGal; reduced anomalies are accurate to 1-2 mGal. Data are more accurate in the valleys than in the mountains because of uncertainties in elevation and in the terrain correction. Logical_Consistency_Report: see open-file report Completeness_Report: Dataset based on geophysical analysis. see open-file report Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Decade of North American Geology Project Publication_Date: 1987 Title: Gravity anomaly map of North America Series_Information: Series_Name: Geological Society of America Map 2, scale 1:5,000,000. Edition: first edition Source_Information: Source_Citation: Citation_Information: Originator: Decade of North American Geology Project Publication_Date: 1987 Title: Gravity anomaly map of North America Series_Information: Series_Name: Geological Society of America Map 2, scale 1:5,000,000. Edition: first edition Source_Information: Source_Citation: Citation_Information: Originator: Snyder, D.B., Roberts, C.W., Saltus, R.W., and Sikora, R.F. Publication_Date: 1982 Title: Gravity database Series_Information: Series_Name: A magnetic tape containing the principal facts of 64,026 gravity stations in the state of California: available from National Technical Information Service, U.S. Department of Commerce, Springfield, VA 22152,PB 82-168287 [description of magnetic tape, PB 82-168279], magnetic tape, 34 p. Edition: first edition Source_Information: Source_Citation: Citation_Information: Nilsen, T.H., and Chapman, R.H., 1974, Bouguer gravity map of California, Trona sheet: California Division of Mines and Geology, scale 1:250,000. Originator: Nilsen, T.H., and Chapman, R.H. Publication_Date: 1974 Title: Bouguer gravity map of California, Trona sheet Series_Information: Series_Name: California Division of Mines and Geology, scale 1:250,000. Edition: first edition Source_Information: Source_Citation: Citation_Information: this report Originator: US Geological Survey Publication_Date: 2012 Title: Gravity survey and depth to basement of Fort Irwin Military Reservation, Mojave Desert, California Series_Information: Series_Name: US Geological Open-File Report Edition: first edition Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geodetic_Model: Horizontal_Datum_Name: Geographic NAD27 Ellipsoid_Name: CLARKE 1866 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Definition: Attributes of gravity stations for Open-File Report 2012-XXXX Entity_Type_Definition_Source: This report Attribute: Attribute_Label: STATION NAME Attribute_Definition: identification string Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: LATD Attribute_Definition: integer degrees of latitude Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: LATM Attribute_Definition: minutes of latitude Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: LOND Attribute_Definition: integer degrees of longitude Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: LONM Attribute_Definition: minutes of longitude Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: ELEV Attribute_Definition: elevation in feet Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: OG Attribute_Definition: observed gravity in mGal Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: FAA Attribute_Definition: Free-air anomaly in mGal Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: SBA Attribute_Definition: Simple Bouguer anomaly in mGal Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: ITC Attribute_Definition: inner zone terrain correction in mGal Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: TC Attribute_Definition: total terrain correction in mGal Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: TC_CODE Attribute_Definition: Letter denoting the extent of the correction, according to the Hayford-Bowie template Attribute_Definition_Source: This report Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: D Enumerated_Domain_Value_Definition: gravitational terrain correction to a distance of 590 meters Enumerated_Domain_Value_Definition_Source: This report Enumerated_Domain: Enumerated_Domain_Value: f Enumerated_Domain_Value_Definition: gravitational terrain correction to a distance of 895 meters Enumerated_Domain_Value_Definition_Source: This report Enumerated_Domain: Enumerated_Domain_Value: M Enumerated_Domain_Value_Definition: gravitational terrain correction to a distance of 2000 meters Enumerated_Domain_Value_Definition_Source: This report Enumerated_Domain: Enumerated_Domain_Value: F Enumerated_Domain_Value_Definition: gravitational terrain correction to a distance of 2290 meters Enumerated_Domain_Value_Definition_Source: This report Enumerated_Domain: Enumerated_Domain_Value: Z Enumerated_Domain_Value_Definition: gravitational terrain correction to a distance of 590 meters using 15-second data Enumerated_Domain_Value_Definition_Source: This report Enumerated_Domain: Enumerated_Domain_Value: Enumerated_Domain_Value_Definition: gravitational terrain correction to an unknown distance, likely 590 meters Enumerated_Domain_Value_Definition_Source: This report Attribute: Attribute_Label: CBA Attribute_Definition: complete Bouguer gravity anomaly in mGal Attribute_Definition_Source: this report Attribute_Domain_Values: Attribute: Attribute_Label: ISO Attribute_Definition: isostatic gravity anomaly in mGal Attribute_Definition_Source: this report Attribute_Domain_Values: Overview_Description: Entity_and_Attribute_Overview: The data file is in ASCII format (fixed). The data define point data with information as follows: LATD: Degree latitude in degrees and minutes LATM: Minute latitude LOND: Degree longitude LONM: Minute latitude ELEV: Elevation in feet OG: Observed gravity FAA: Free-air anomaly SBA: Simple Bouguer anomaly ITC: Inner terrain correction out to a radius of various distances from the station, for a density of 2.67 g/cc TC: Total terrain correction from the station to 166.7 km for a density of 2.67 g/cc TC CODE: Letter denoting the extent of the correction, according to the Hayford-Bowie and Hammer templates (D=590 meters; f=895 meters; M=2000 meters; F=2291 meters; Z=590 meters calculated from 15-sec data; no letter means unknown, but likely D). See Spielman and Ponce (1984) for additional explanation. CBA: Complete Bouguer anomaly reduced for a density of 2.67 g/cc ISO: Isostatic residual anomaly values Overview_Description: Entity_and_Attribute_Overview: point data representing gravity data Metadata_Reference_Information: Metadata_Date: 20120712 Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata