Citation:
Citation_Information:
Originator: Robert E. Powell
Publication_Date: 2002
Title:
Geologic map and digital database of the Pinto Mountain 7.5
minute quadrangle, Riverside County, California
Edition: Version 1.0
Geospatial_Data_Presentation_Form: Vector digital data
Series_Information:
Series_Name: U.S. Geological Survey Open-File Report
Issue_Identification: 02-491
Publication_Information:
Publication_Place: Menlo Park, California
Publisher: U.S. Geological Survey
Online_Linkage: http://pubs.usgs.gov/of/2002/0491/
Description:
Abstract:
This data set maps and describes the geology of the Pinto Mountain 7.5 minute
quadrangle, Riverside County, southern California. The quadrangle, situated in
Joshua Tree National Park in the eastern Transverse Ranges physiographic and
structural province, encompasses parts of the northeastern Hexie Mountains,
central Pinto Mountains, and central Pinto Basin.
The quadrangle is underlain by a basement terrane comprising Proterozoic
metamorphic rocks, Mesozoic plutonic rocks, and Mesozoic and Mesozoic and (or)
Cenozoic hypabyssal dikes. The basement terrane is capped by a widespread
Tertiary erosion surface preserved in remnants in the Hexie and Pinto Mountains
and buried beneath Cenozoic deposits in Pinto Basin. Locally, a cover of
Miocene sedimentary deposits and basalt overlie the erosion surface.
Quaternary and (or) Tertiary lacustrine deposits crop out in the center of
Pinto Basin and interfinger laterally with sandstone, conglomerate, and debris
flows originating in the Pinto and Hexie Mountains. A sequence of at least
three Quaternary pediments is planed into the north piedmonts of the Hexie and
Eagle Mountains, each in turn overlain by successively younger residual and
alluvial, surficial deposits. The Tertiary erosion surface is deformed and
broken by north-northwest-trending, high-angle, dip-slip faults in the Pinto
and Eagle Mountains and an east-west trending system of high-angle dip- and
left-slip faults along the range fronts facing Pinto Basin. In and around the
Pinto Mountain quadrangle, faults of the north-northwest-trending set displace
Miocene sedimentary rocks and basalt deposited on the Tertiary erosion surface
and some of the faults may offset Pliocene and (or) Pleistocene deposits that
accumulated on the oldest pediment. Faults of this system appear to be
overlain by Pleistocene deposits that accumulated on younger pediments.
East-west trending faults are younger than and perhaps in part coeval with
faults of the northwest-trending set.
The Pinto Mountain database was created using ARCVIEW and ARC/INFO, which are
geographical information system (GIS) software products of Envronmental Systems
Research Institute (ESRI). The database comprises eight coverages: (1) a geologic
layer showing the distribution of geologic contacts and units; (2) a structural
layer showing the distribution of faults (arcs) and fault ornamentation data
(points); (3) a layer showing the distribution of dikes (arcs); structural point
data layers showing (4) bedding attitudes, (5) foliation attitudes, (6)
lineations, (7) minor fold axes; and (8) cartographic map elements, including
unit label leaders and geologic unit annotation. The dataset also includes a
scanned topographic base at a scale of 1:24,000. Within the database coverages,
geologic contacts , faults, and dikes are represented as lines (arcs and routes),
geologic units as areas (polygons and regions), and site-specific data as points.
Polygon, region, arc, route, and point attribute tables uniquely identify each
geologic datum and link it to descriptive tables that provide more detailed
geologic information.
The digital database is accompanied by two derivative maps: (1) A portable
document file (.pdf) containing a navigable graphic of the geologic map on a
1:24,000 topographic base and (2) a PostScript graphic-file containing the
geologic map on a 1:24,000 topographic base. Each of these map products is
accompanied by a marginal explanation consisting of a Description of Map Units
(DMU), a Correlation of Map Units (CMU), and a key to point and line symbols.
The database is further accompanied by three document files: (1) a readme that
lists the contents of the database and describes how to access it, (2) a pamphlet
file that describes the geology of the quadrangle, and (3) this metadata file.
Purpose:
The data set for the Pinto Mountain 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 Geological Survey. The Pinto
Mountain 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 Pinto
Mountain 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 Pinto Mountain 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 Pinto Mountain 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 the Pinto Basin.
Supplemental_Information:
Map nomenclature and symbols
Within the geologic map database, map units are identified by standard geologic
map criteria such as formation-name, age, and lithology. The authors have
attempted to adhere to the stratigraphic nomenclature of the U.S. Geological
Survey and the North American Stratigraphic Code, but the database has not
received a formal editorial review of geologic names.
Geologic map unit labels are present in three forms in the database. First, map
unit labels are entered into the database through various items in the polygon
attribute table, dike arc attribute table, and region attribute tables. Geologic
map units are tabulated in items such as UNIT_LABEL and POLY_LABEL, where they are
identified by plain-text unit labels (e.g., Qyam1, Prjgg). These labels do not
show subscript offsets and do not contain conventional stratigraphic age symbols,
i.e., Proterozoic appears as 'Pr'. Second, for the purpose of plotting the map,
the item PLOT_LABEL, located in the polygon attribute and map display tables,
identifies the unit label as it is plotted by Arc/Info (e.g., Qyam1, <jgg), again
without subscripts and containing substitute characters for conventional
stratigraphic age symbols: Proterozoic appears as '<'. The substitute character in
PLOT_LABEL invokes its corresponding symbol from the GeoAge font group to generate
map plots that display conventional stratigraphic symbols. Third, annotation
labels for map units, derived from the item PLOT_LABEL but showing subscripts
(e.g., Qyam1), are stored in the annotation subclass anno.geo of the arc coverage
pmtn_carto/.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 1964
Ending_Date: 2002
Currentness_Reference: New data
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As Needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -115.87509139
East_Bounding_Coordinate: -115.74990861
North_Bounding_Coordinate: 33.99999995
South_Bounding_Coordinate: 33.87498418
Keywords:
Theme:
Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: geology
Theme_Keyword: geologic maps
Theme_Keyword: surficial geologic units
Theme_Keyword: bedrock geologic units
Theme_Keyword: geologic structure
Theme_Keyword: metamorphic rocks
Theme_Keyword: plutonic rocks
Theme_Keyword: unconsolidated deposits
Theme_Keyword: geospatial datasets
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: fault
Theme_Keyword: erosion surface
Theme_Keyword: pediment
Theme_Keyword: soil
Theme_Keyword: alluvial deposits
Theme_Keyword: dike
Theme_Keyword: batholith
Theme_Keyword: metamorphic rocks
Theme_Keyword: plutonic rocks
Theme_Keyword: hypabyssal rocks
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Categories
Theme_Keyword: geoscientificInformation
Place:
Place_Keyword_Thesaurus: none
Place_Keyword: southern California
Place_Keyword: Riverside County
Place_Keyword: Joshua Tree National Park
Place_Keyword: eastern Transverse Ranges
Place_Keyword: Pinto Mountains
Place_Keyword: Hexie Mountains
Place_Keyword: Pinto Basin
Place_Keyword: Pinto Mountain 7.5' quadrangle
Place_Keyword: Hexie Mountains 15' quadrangle
Place_Keyword: Eagle Mountains 30' x 60' quadrangle
Place:
Place_Keyword_Thesaurus: Augmented FIPS 10-4 and FIPS 6-4
Place_Keyword: f06065 = Riverside
Stratum:
Stratum_Keyword_Thesaurus: None
Stratum_Keyword: Pinto Gneiss
Stratum_Keyword: Granite of Pinto Wash
Stratum_Keyword:
Porphyritic quartz monzonite, monzogranite, and granodiorite
of San Bernardino Wash
Stratum_Keyword: Sedimentary strata of Pinto Basin
Stratum_Keyword: Quartzite of Pinto Mountain
Stratum_Keyword: Dolomite of Iron Chief mine
Stratum_Keyword: Alluvium
Access_Constraints: None
Use_Constraints:
Spatial Resolution. Use of this digital geologic map should not violate the
spatial resolution of the data. The Pinto Mountain 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 Pinto Mountain 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
Pinto Mountain 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 Pinto Mountain 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.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Robert E. Powell
Contact_Organization:
U.S.Geological Survey, Western Region, Earth Surface Processes Team
Contact_Position: Project geologist
Contact_Address:
Address_Type: mailing address
Address:
U.S. Geological Survey
Room 202
West 904 Riverside Avenue
City: Spokane
State_or_Province: Washington
Postal_Code: 99201-1087
Country: USA
Contact_Voice_Telephone: (509) 368-3120
Contact_Facsimile_Telephone: (509) 368-3199
Contact_Electronic_Mail_Address: rpowell@usgs.gov
Browse_Graphic:
Browse_Graphic:
Data_Set_Credit:
Pamela Cossette prepared the digital data set.
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 Geological Survey, 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.
Technical review by Fred K. Miller has led to significant improvements in the
database and in the map plot file. Digital review by Rachel Hauser Alvarez has
allowed us to further improve the digital database.
Native_Data_Set_Environment:
SunOS, 5.8, sun4u UNIX
ARC/INFO version 8.1
Cross_Reference:
Citation_Information:
Originator: Robert E. Powell
Publication_Date: 2001
Title:
Geologic map and digital database of the Conejo Well 7.5 minute quadrangle,
Riverside County, California
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: U.S. Geological Survey Open-File Report
Issue_Identification: 01-31
Publication_Information:
Publication_Place: Menlo Park, California
Publisher: U.S. Geological Survey
Online_Linkage: http://pubs.usgs.gov/of/2001/of01-031/
Cross_Reference:
Citation_Information:
Originator: Robert E. Powell
Publication_Date: 2001
Title:
Geologic map and digital database of the Porcupine Wash 7.5 minute quadrangle,
Riverside County, California
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: U.S. Geological Survey Open-File Report
Issue_Identification: 01-30
Publication_Information:
Publication_Place: Menlo Park, California
Publisher: U.S. Geological Survey
Online_Linkage: http://pubs.usgs.gov/of/2001/0030/