Geology By Howard G. Wilshire, and GIS Database by: David R. Bedford and Teresa Coleman, 2002, Digital Version of 'Open-File Report 92-182: Geologic Map of the Marl Mountains Quadrangle, San Bernardino County, California': Open-File Report 02-271, U.S. Geological Survey, Menlo Park, California.Online Links:
This is a Vector data set. It contains the following vector data types (SDTS terminology):
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest 0.000008
Ordinates (y-coordinates) are specified to the nearest 0.000008
Planar coordinates are specified in meters
The horizontal datum used is North American Datum of 1983.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257222.
Sequential unique whole numbers that are automatically generated.
Coordinates defining the features.
Whole numbers that are automatically generated.
Whole numbers that are automatically generated.
Whole numbers that are automatically generated.
Whole numbers that are automatically generated.
Positive real numbers that are automatically generated.
Sequential unique whole numbers that are automatically generated.
User defined attribute
| Value | Definition |
|---|---|
| contact, certain | Boundary between two mapped units that was observed, the location of which is well known and is described in Positional_Accuracy |
| crest of crater in cinder cone | crest of crater in cinder cone |
| dike | dike |
| dike, Kap | a dike composed of map unit Kap |
| dike, Km | dike composed of map unit Km |
| dike, Kt | dike composed of map unit Kt |
| fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset. Locational accuracy is well located |
| map boundary | Edge of mapped area, used to bound polygons at the edge of the map database |
| dike, Ktm | dike composed of map unit Ktm |
| dike, QTbi | a dike composed of map unit QTbi |
| dike, TKm | a dike composed of unit TKm |
| dike, TKr | a dike composed of map unit TKr |
User defined attribute
User defined attribute
Sequential unique whole numbers that are automatically generated.
Coordinates defining the features.
Positive real numbers that are automatically generated.
Positive real numbers that are automatically generated.
Sequential unique whole numbers that are automatically generated.
User-defined feature number.
Geologic map unit labels are described in the accompanying geologic report
User-defined attribute.
User-defined attribute.
Sequential unique whole numbers that are automatically generated.
Coordinates defining the features.
Positive real numbers that are automatically generated.
Positive real numbers that are automatically generated.
Sequential unique whole numbers that are automatically generated.
User-defined feature number.
| Value | Definition |
|---|---|
| Sample | Sample for K/Ar analysis |
The sample number, as depicted on the map and report
User-defined attribute.
User-defined attribute.
Sequential unique whole numbers that are automatically generated.
Coordinates defining the features.
Positive real numbers that are automatically generated.
Positive real numbers that are automatically generated.
Sequential unique whole numbers that are automatically generated.
User-defined feature number.
| Value | Definition |
|---|---|
| bedding | stratigraphic bedding |
| foliation | foliation |
| horz bedding | horizontal (flat) bedding |
| vert foliation and bedding | vertical foliation |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 90 |
| Units: | degrees |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 360 |
| Units: | degrees, based on the 'right-hand-rule' |
User-defined attribute.
User-defined attribute.
Map units (polygons) are described in the polygon attribute table (marlm-geo.pat). The identities of the map units are recorded in the PTYPE field by map label (i.e. Ts). For a description of the map units, consult the PostScript or PDF explanation pamphlets in this report.
Geologic lines (arcs) are recorded as strings of vectors and are described in the arc attribute table (marlm-geo.aat). They define the boundaries of the map units, the faults, and the map boundaries. These distinctions, including the geologic identities of the unit boundaries, are recorded in the LTYPE field. Attributes for geologic lines generally follow a scheme of the type of geologic line (i.e. fault), followed by a locational and/or scientific modifier (i.e. approx. located or queried).
David Bedford
U.S. Geological Survey
Geologist
345 Middlefield Rd, MS975
Menlo Park, CA 94025
USA
650-329-4924 (voice)
650-329-4936 (FAX)
dbedford@usgs.gov
The purpose of this dataset is to archive previous geologic mapping in the area and to enable the further use, reclassification, and analysis of existing geologic map data in the area.
Wilshire, H.G., 1992, Geologic Map of the Marl Mountains Quandrangle, San Bernardino County, California: Open-File Report 92-182, U.S. Geological Survey, Menlo Park, California.
Map units, geologic line types, dip values, and other attribute data were appended with a '?' if the feature was not labeled, or clearly labeled, on the original map. Dip values in the 'dip' field of the structural geology points layer that were not clearly identifiable were calculated as the NEGATIVE assumed value, and annotation values were appended with a '?' (such as if it is assumed that a dip was 37, but was not clear, -37 was entered into the dababase, and annotation of 37? was created). For instances where the dip value was absent or completely indeterminate, the value '99' was used, and no anotation was created.
No positional accuracy information was prescribed to geologic contacts in the original report (such as approximate, concealed, etc), and thus all geologic contacts were attributed as well placed (certain, or solid lines) although the original nature of the contact is unknown.
point, line, and polygon features were vectorized from scans of the original maps and were edited to represent the original map at a scale of 1:24,000. This includes removing unnecessary lines, and closing all polygons. All vector geometries were then transformed into UTM coordinates with an RMS error of .003 or less.
No positional accuracy information was prescribed to geologic contacts in the original report (such as approximate, concealed, etc), and thus all geologic contacts were attributed as well placed (certain, or solid lines) although the original nature of the contact is unknown.
This report is intended to completely represent and describe the original publication of the surficial and bedrock materials of the map area at a scale of 1:24000.
Geologic lines attributed as a 'contact' do not separate geologic map units of the same type, and are not considered as 'dangles'. All geologic polygons are attributed with map unit designators found in the original report.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- Acknowledgement of the U.S. Geological Survey; Uses of this digital geologic map should not violate the spatial resolution of the data. Although the digital form of the data removes the constraint imposed by the scale of a paper map, the detail and accuracy inherent in map scale are also present in the digital data. The fact that this database was edited at a scale of 1:24,000 means that higher resolution information is not present in the dataset. Plotting at scales larger than 1:24,000 will not yield greater real detail, although it may reveal fine-scale irregularities below the intended resolution of the database. Similarly, where this database is used in combination with other data of higher resolution, the resolution of the combined output will be limited by the lower resolution of these data.
U.S. Geological Survey
c/o Marl Mountians, California Database
Database coordinator
345 Middlefield Road, MS975
Menlo Park, California 94025
USA
(650) 329-4924 (voice)
All files for this report can be accessed via the World Wide Web at: <http://geopubs.wr.usgs.gov/open-file/of02-271> or through File Transfer Protocol (FTP) at <ftp://geopubs.wr.usgs.gov/pub/open-file/of02-271/>
This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.This database, identified as "Digital Version of 'Open-File Report 92-182: Geologic Map of the Marl Mountains Quadrangle, San Bernardino County, California'" has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use.
| Data format: | ARCE (version 8.0) ARC/INFO export files, explanatory materials, and printable maps for the digital database can be downloaded at the specified URL Size: 0.277 |
|---|---|
| Network links: |
<http://geopubs.wr.usgs.gov/open-file/of02-271/> <ftp://geopubs.wr.usgs.gov/pub/open-file/of02-271/> |
Database files, PostScript plotfiles, and related files can be obtained by sending a tape or CDR (Recordable CD-ROM) with request and return address to:Marl Mountains, California Database c/o Database Coordinator U.S. Geological Survey 345 Middlefield Road, M/S 975 Menlo Park, CA 94025
Do not omit any part of this address!
The compressed tar file will be returned on the tape or CD-ROM. The acceptable tape type is: 2.3 or 5.0 GB, 8 mm Exabyte tape.
U.S. Geological Survey
c/o David R Bedford
Geologist
345 Middlefield Rd, MS975
Menlo Park, California 94025
USA
650-329-4924 (voice)
650-329-4936 (FAX)
dbedford@usgs.gov