Online Links:
| 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 |
| Value | Definition |
|---|---|
| CZs | Siliciclastic rocks (Cambrian and Late Proterozoic) |
| Kt | Felsic members of Teutonia batholith |
| Kt? | Felsic members of Teutonia batholith (questionably) |
| Ktm | Mafic member of Teutonia batholith |
| Q2 | Unit 2 (Pleistocene)--Moderately to well dissected alluvial deposits of sand and gravel. |
| Q2b | Subunit 2b-Moderately dissected alluvial deposits about 2 to 6 m above adjacent drainages. |
| Q3 | Unit 3 (Holocene to Pleistocene)--Undissected to little dissected alluvial deposits of unstratified to weakly stratified sand and gravel. |
| Q3a | Subunit 3a--Little dissected deposits 1 to 3 m above active channels. |
| Q3b | Subunit 3b-Little dissected deposits about 1 to 2 m above active channels. |
| Q4 | Unit 4 (Holocene)--Alluvial fill of active channels |
| Q3-4 | Units 3 and 4? |
| Qcp | Playa deposits in volcanic craters (Holocene) |
| QTa | Coarse ash and lapilli tuff (Pleistocene) |
| QTbi | Basalt dikes and plugs (Holocene? to late Miocene) |
| QTf | Lava flow (Pleistocene to late Pliocene) (field value includes numerical sequence information as well) |
| QTpb | Pyroclastic breccia (Pleistocene to late Pliocene) |
| QTt | Deposits of red oxidized scoria and black unoxidized scoria consisting of pebble to cobble size fragments |
| QTt? | Deposits of red oxidized scoria and black unoxidized scoria consisting of pebble to cobble size fragments (questionably) |
| QTta | Talus and colluvial deposits derived from cinder cones and basalt flows (Holocene to early Pliocene) |
| QTtb | Deposits of blocks and bombs, consisting of boulder-size fragments as much as 5 m in diameter. |
| QTtc | Tuffaceous breccia (Pleistocene to late Miocene) |
| Tf | Lava flow (early Pliocene to late Miocene) |
| TKpt | Pseudotachylite (Tertiary? or Cretaceous?) |
| TKr | Rhyolitic dikes (Tertiary? or Cretaceous?) |
| Ts | Sedimentary rocks-Fine-grained sandstone, siltstone, shale, fresh water limestone locally present near base of deposits. |
| Ts? | Sedimentary rocks-Fine-grained sandstone, siltstone, shale, fresh water limestone locally present near base of deposits. (questionably) |
| X1 | Felsic gneiss |
| X2 | Mafic gneiss |
| Xu | Undivided mafic and felsic gneiss |
| Xu? | Undivided mafic and felsic gneiss (questionably) |
| Value | Definition |
|---|---|
| Sample | Sample for K/Ar analysis |
| 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' |
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.
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.
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: | Geologic units, structural features, and measurements in format ARCE (version 8.0) Size: 4.2 |
|---|---|
| Network links: |
http://pubs.usgs.gov/of/2002/0271/of02-271data.tar |
