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| Value | Definition |
|---|---|
| Qa | Very young alluvial deposits (late Holocene) |
| Qa2 | Very young alluvial deposits, Unit 2 (late Holocene) |
| Qa1 | Very young alluvial deposits, Unit 1 (late Holocene) |
| Qyai3 | Young alluvial deposits, insensitive source, Unit 3 (late and (or) middle Holocene) |
| Qyai2 | Young alluvial deposits, insensitive source, Unit 2 (middle Holocene) |
| Qyai1 | Young alluvial deposits, insensitive source, Unit 1 (middle and (or) early Holocene and (or) latest Pleistocene?) |
| Qyas2,3 | Young alluvial deposits, sensitive source, Units 2 and 3 (late and (or) middle Holocene) |
| Qyas3 | Young alluvial deposits, sensitive source, Unit 3 (late and (or) middle Holocene) |
| Qyas2 | Young alluvial deposits, sensitive source, Unit 2 (late and (or) middle Holocene) |
| Qyas2? | Young alluvial deposits, sensitive source, Unit 2? (late and (or) middle Holocene) |
| Qyaos | Young alluvial deposits, oxidized, sensitive source (Holocene and latest Pleistocene?) |
| Qoai3 | Old alluvial deposits, insensitive source, Unit 3 (late Pleistocene) |
| Qoai2 | Old alluvial deposits, insensitive source, Unit 2 (middle? Pleistocene) |
| Qoaps | Old alluvial deposits, pavemented, sensitive source (late Pleistocene) |
| Qoaos | Old alluvial deposits, oxidized, sensitive source (middle? Pleistocene) |
| Qoaos? | Old alluvial deposits, oxidized, sensitive source? (middle? Pleistocene) |
| Qoars | Old alluvial and (or) regolithic deposits, sensitive source (middle? Pleistocene) |
| Qoc | Old colluvial deposits (Pleistocene) |
| Qoc1,2 | Old colluvial deposits, Units 1 and 2 (Pleistocene) |
| Qovork | Old and (or) very old regolithic deposits, cemented (middle? and (or) early? Pleistocene) |
| Qvoa | Very old alluvial deposits (middle and early Pleistocene) |
| QTs? | Sedimentary deposits? (Quaternary and (or) Tertiary) |
| QTrcp | Regolith, monzogranite of Cottonwood Pass (Quaternary and Tertiary) |
| QTrcp? | Regolith, monzogranite of Cottonwood Pass? (Quaternary and Tertiary) |
| QTrpb | Regolith, granodiorite of Pinto Basin (Quaternary and Tertiary) |
| QTrpb? | Regolith, granodiorite of Pinto Basin? (Quaternary and Tertiary) |
| QTrp | Regolith, Pinto Gneiss (Quaternary and Tertiary) |
| Trscp | Saprolite, monzogranite of Cottonwood Pass (Tertiary) |
| Trscp? | Saprolite, monzogranite of Cottonwood Pass? (Tertiary) |
| KJmgccp | Monzogranite of Cottonwood Pass (Cretaceous or Jurassic) |
| KJmgccp? | Monzogranite of Cottonwood Pass? (Cretaceous or Jurassic) |
| Kgdpb | Granodiorite of Pinto Basin (Cretaceous) |
| Kgdpb? | Granodiorite of Pinto Basin? (Cretaceous) |
| TrPmc | Monzodiorite of Munsen Canyon (Triassic or Permian) |
| Prmag | Augen gneiss of Monument Mountain (Middle Proterozoic) |
| Prpg | Pinto Gneiss of Miller, 1938 (Proterozoic) |
| Prpgd | Pinto Gneiss, dark (Proterozoic) |
| Prpgd? | Pinto Gneiss, dark? (Proterozoic) |
| Prpgl | Pinto Gneiss, leucocratic granitic orthogneiss (Middle Proterozoic) |
| Prpgl? | Pinto Gneiss, leucocratic granitic orthogneiss? (Middle Proterozoic) |
| Prppw | Siliceous granofels of Wilson Canyon (Proterozoic) |
| TKq? | Quartz? (Tertiary or Cretaceous) |
| TJh? | Hypabyssal intrusive rocks? (Tertiary or Jurassic) |
| Value | Definition |
|---|---|
| Prhgc | Gneiss complex of Hexie Mountains (Proterozoic) |
| Prmag | Augen gneiss of Monument Mountain (Middle Proterozoic) |
| Prmg | Porphyritic granodiorite, monzogranite, and augen gneiss of Monument Mountain (Middle Proterozoic) |
| Prpg | Pinto Gneiss of Miller, 1938 (Proterozoic) |
| Prpgd | Pinto Gneiss, dark (Proterozoic) |
| Prpgl | Pinto Gneiss, leucocratic granitic orthogneiss (Middle Proterozoic) |
| Prpp | Metsedimentary and (or) metamorphosed hydrothermally altered rocks of Pinkham Canyon (Proterozoic) |
| Prppw | Siliceous granofels of Wilson Canyon (Proterozoic) |
| Value | Definition |
|---|---|
| Qovork | Old and (or) very old regolithic deposits, cemented (middle? and (or) early? Pleistocene) |
| QTr | Regolith (Quaternary and Tertiary) |
| QTrmgc | Regolith, coarse-grained monzogranite (Quaternary and Tertiary) |
| QTrcp | Regolith, monzogranite of Cottonwood Pass (Quaternary and Tertiary) |
| QTrgd | Regolith, granodiorite (Quaternary and Tertiary) |
| QTrpb | Regolith, granodiorite of Pinto Basin (Quaternary and Tertiary) |
| QTrp | Regolith, Pinto Gneiss (Quaternary and Tertiary) |
| Tr | Regolith (Tertiary) |
| Trs | Saprolite (Tertiary) |
| Trscp | Saprolite, monzogranite of Cottonwood Pass (Tertiary) |
| Value | Definition |
|---|---|
| KJmgc | Monzogranite, coarse-grained (Cretaceous and (or) Jurassic) |
| KJmgccp | Monzogranite of Cottonwood Pass (Cretaceous or Jurassic) |
| Kgd | Granodiorite (Cretaceous) |
| Kgdpb | Granodiorite of Pinto Basin (Cretaceous) |
| TrPmc | Monzodiorite of Munsen Canyon (Triassic or Permian) |
| Mzbc | Batholith of Transverse Ranges and Mojave Desert, central belt (Mesozoic) |
| Mzb | Batholith of Transverse Ranges and Mojave Desert (Mesozoic) |
| Prmag | Augen gneiss of Monument Mountain (Middle Proterozoic) |
| Prmg | Porphyritic granodiorite, monzogranite, and augen gneiss of Monument Mountain (Middle Proterozoic) |
| Prpgg | Porphyritic granitoids and augen gneiss (Middle Proterozoic) |
| Prpgl | Pinto Gneiss, leucocratic granitic orthogneiss (Middle Proterozoic) |
| Value | Definition |
|---|---|
| Qa | Very young alluvial deposits (late Holocene) |
| Qa2 | Very young alluvial deposits, Unit 2 (late Holocene) |
| Qa1 | Very young alluvial deposits, Unit 1 (late Holocene) |
| Qya | Young alluvial deposits (Holocene and latest Pleistocene?) |
| Qyai | Young alluvial deposits, insensitive source (Holocene and latest Pleistocene?) |
| Qyai3 | Young alluvial deposits, insensitive source, Unit 3 (late and (or) middle Holocene) |
| Qyai2 | Young alluvial deposits, insensitive source, Unit 2 (middle Holocene) |
| Qyai1 | Young alluvial deposits, insensitive source, Unit 1 (middle and (or) early Holocene and (or) latest Pleistocene?) |
| Qyas | Young alluvial deposits, sensitive source (Holocene and latest Pleistocene?) |
| Qyas2,3 | Young alluvial deposits, sensitive source, Units 2 and 3 (late and (or) middle Holocene) |
| Qyas3 | Young alluvial deposits, sensitive source, Unit 3 (late and (or) middle Holocene) |
| Qyas2 | Young alluvial deposits, sensitive source, Unit 2 (late and (or) middle Holocene) |
| Qyas2? | Young alluvial deposits, sensitive source, Unit 2? (late and (or) middle Holocene) |
| Qyaos | Young alluvial deposits, oxidized, sensitive source (Holocene and latest Pleistocene?) |
| Qyua | Very young and young alluvial deposits (Holocene) |
| Qoaos? | Old alluvial deposits, oxidized, sensitive source? (middle? Pleistocene) |
| Qoa | Old alluvial deposits (Pleistocene) |
| Qoai | Old alluvial deposits, insensitive source (Pleistocene) |
| Qoai3 | Old alluvial deposits, insensitive source, Unit 3 (late Pleistocene) |
| Qoai2 | Old alluvial deposits, insensitive source, Unit 2 (middle? Pleistocene) |
| Qoas | Old alluvial deposits, sensitive source (Pleistocene) |
| Qoaps | Old alluvial deposits, pavemented, sensitive source (late Pleistocene) |
| Qoaos | Old alluvial deposits, oxidized, sensitive source (middle? Pleistocene) |
| Qoars | Old alluvial and (or) regolithic deposits, sensitive source (middle? Pleistocene) |
| Qoua | Old and very old alluvial deposits, undivided (Pleistocene) |
| Qoc | Old colluvial deposits (Pleistocene) |
| Qoc1,2 | Old colluvial deposits, Units 1 and 2 (Pleistocene) |
| Qovork | Old and (or) very old regolithic deposits, cemented (middle? and (or) early? Pleistocene) |
| Qvoa | Very old alluvial deposits (middle and early Pleistocene) |
| QTs? | Sedimentary deposits? (Quaternary and (or) Tertiary) |
| Value | Definition |
|---|---|
| TKq? | Quartz? (Tertiary or Cretaceous) |
| Value | Definition |
|---|---|
| TJh? | Hypabyssal intrusive rocks? (Tertiary or Jurassic) |
| Value | Definition |
|---|---|
| Qopb | Old pedogenic B-horizon (middle? Pleistocene) |
| Value | Definition |
|---|---|
| TKdp | Dacite porphyry dike (Tertiary or Cretaceous) |
| TJd | Dike (Tertiary, Cretaceous, or Jurassic) |
| Kap | Aplite dike (Cretaceous) |
Geologic mapping, topical studies, and digital preparation for this report were sponsored jointly by the following: (1) the National Cooperative Geologic Mapping Program of the U.S. Geological Survey, (2) California Division of Mines and Geology, and (3) the National Park Service (Joshua Tree National Park).
This database was prepared in the GIS laboratory at the Spokane Field Office of the USGS in Spokane, Washington. The facility is maintained primarily by the Mineral Resource Surveys Program and supported in part by the National Geologic Mapping Program. We thank Paul C. Hyndman and Steven R. Munts in Spokane and Rachel Hauser Alvarez of the SCAMP GIS laboratory at the University of California, Riverside for their assistance in solving problems encountered during digital preparation of the data set.
Technical review by Jonathan C. Matti has led to significant improvements in the database and in the map plot file. Todd T. Fitzgibbon has examined the digital database file for internal logical consistency, has reviewed the metadata file, and has tested the viability of digital products.
The data set for the Porcupine Wash quadrangle has been prepared by the Southern California Areal Mapping Project (SCAMP), a cooperative project sponsored jointly by the U.S. Geological Survey and the California Division of Mines and Geology. The Porcupine Wash data set represents part of an ongoing effort to create a regional GIS geologic database for southern California. This regional digital database, in turn, is being developed as a contribution to the National Geologic Map Database of the National Cooperative Geologic Mapping Program of the USGS. The Porcupine Wash database has been prepared in cooperation with the National Park Service as part of an ongoing project to provide Joshua Tree National Park with a geologic map base for use in managing Park resources and developing interpretive materials.
The digital geologic map database for the Porcupine Wash quadrangle has been created as a general-purpose data set that is applicable to land-related investigations in the earth and biological sciences. Along with geologic map databases in preparation for adjoining quadrangles, the Porcupine Wash database has been generated to further our understanding of bedrock and surficial processes at work in the region and to document evidence for seismotectonic activity in the eastern Transverse Ranges. The database is designed to serve as a base layer suitable for ecosystem and mineral resource assessment and for building a hydrogeologic framework for Pinto Basin.
Online Links:
Are there legal restrictions on access or use of the data?Access_Constraints: None
Use_Constraints:Spatial Resolution. Use of this digital geologic map should not violate the spatial resolution of the data. The Porcupine Wash geologic map and database was developed using digital orthophotograph quarter quadrangles (DOQQs) as a base. DOQQs have a pixel resolution of 1 m and are accurate to a scale of 1:12,000 (1 in = 1,000 ft). Any enlargement beyond 1:12,000 exceeds the spatial resolution of the geologic data and should not be used in lieu of a more detailed site-specific geologic evaluation. Similarly, the digital topographic base map is derived from the U.S. Geological Survey, 1:24,000-scale Porcupoine Wash 7.5 minute quadrangle (provisional edition, 1986); any enlargement beyond 1:24,000 exceeds the spatial resolution of the topographic data. Plotting or viewing of the data at scales larger than 1:12,000 on the DOQQ base, or larger than 1:24,000 on the topographic base, will not yield greater real detail, although it may reveal fine-scale irregularities below the intended resolution of the database. Where the geologic data is used in combination with the topographic data, the resolution of the combined output is limited by the lower resolution of the topographic data. 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.
Content. This database, identified as "Geologic map and digital database of the Porcupine Wash 7.5 minute quadrangle, Riverside County, California" has been approved for release and publication by the Director of the U.S. Geological Survey. 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 the condition that neither the USGS nor the United States Government may be held responsible for any damages resulting from its authorized or unauthorized use. This database 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.
Faults. The Porcupine Wash database is sufficiently detailed to identify and characterize many actual and potential geologic hazards represented by faults, but it is not sufficiently detailed for site-specific determinations or evaluations of these features. Faults shown do not take the place of fault-rupture hazard zones designated by the California State Geologist (see, for example, Hart, 1988; Hart and Bryant, 1997).
Hart, E. W., 1988, Fault-rupture zones in California; Alquist-Priolo Special Studies Zones Act of 1972 with index to special studies zones maps (revised, 1988): California Division of Mines and Geology Special Publication 42.
Hart, E. W., and Bryant, W.A., 1997, Fault-rupture zones in California; Alquist-Priolo Special Studies Zones Act of 1972 with index to special studies zones maps (revised, 1997): California Division of Mines and Geology Special Publication 42.
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 delivery, installation, operation, or support by USGS.
This digital, geologic map database of the Porcupine Wash 7.5'quadrangle, and any derivative maps thereof, is not meant to be used or displayed at any map scale larger than 1:12,000 on the DOQQ base or 1:24,000 on the topograhic base.
| Data format: | Geologic polygons, lines, and symbols, and dictionary coverages, with additional text. in format ARCE (version 7.2.1) Size: 5.5 |
|---|---|
| Network links: |
http://pubs.usgs.gov/of/2001/0030/pwash.tar.gz |
