Geologic map and digital database of the San Bernardino Wash 7.5 minute quadrangle, Riverside County, California

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What does this data set describe?

Title:
Geologic map and digital database of the San Bernardino Wash 7.5 minute quadrangle, Riverside County, California
Abstract:
This data set maps and describes the geology of the San Bernardino Wash 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 northwestern Eagle Mountains, east-central Pinto Basin, and eastern Pinto Mountains.
The quadrangle is underlain by a basement terrane comprising metamorphosed Proterozoic strata, Mesozoic plutonic rocks, and Jurassic and Mesozoic and (or) Cenozoic hypabyssal dikes. The basement terrane is capped by a widespread Tertiary erosion surface preserved in remnants in the Pinto and Eagle Mountains and buried beneath Cenozoic deposits in Pinto Basin. Locally, a cover of Miocene sedimentary deposits and basalt overlie the erosion surface. A sequence of at least three Quaternary pediments is planed into the north piedmont of the 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 San Bernardino Wash 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 San Bernardino Wash 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 five 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); a structural point data layer showing (4) bedding and metamorphic foliation attitudes, and (5) 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.
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., Qyamg1, Prpqp). 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., Qyamg1, <pqp), 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., Qyamg1), are stored in the annotation subclass anno.geo of the arc coverage sbwash_carto/.
  1. How might this data set be cited?
    Powell, Robert E., 2002, Geologic map and digital database of the San Bernardino Wash 7.5 minute quadrangle, Riverside County, California: U.S. Geological Survey Open-File Report 02-498, U.S. Geological Survey, Menlo Park, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -115.7500914
    East_Bounding_Coordinate: -115.6249086
    North_Bounding_Coordinate: 33.99999995
    South_Bounding_Coordinate: 33.87498418
  3. What does it look like?
    http://pubs.usgs.gov/of/2002/0498/images/sbwash.jpg (JPEG)
    Reduced-size image of the entire map sheet, 400x307 pixels, 47k bytes
    http://pubs.usgs.gov/of/2002/0498/pdf/sbwash_map.pdf (PDF)
    Printable representation of the map sheet, 11.2 megabytes.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1964
    Ending_Date: 2002
    Currentness_Reference:
    Data collection period
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Point (1902)
      • String (4743)
      • GT-polygon composed of chains (1903)
    2. What coordinate system is used to represent geographic features?
      The map projection used is Polyconic.
      Projection parameters:
      Longitude_of_Central_Meridian: -115.6875
      Latitude_of_Projection_Origin: 33.875
      False_Easting: 0.0
      False_Northing: 0.0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.000001
      Ordinates (y-coordinates) are specified to the nearest 0.000001
      Planar coordinates are specified in Meters
      The horizontal datum used is North American Datum of 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.4.
      The flattening of the ellipsoid used is 1/294.98.
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    The Geologic Map and Digital Database of the San Bernardino Wash 7.5 minute quadrangle includes five double precision ARCINFO coverages: sbwash_geo (geology); sbwash_flt (faults and structural line ornamentation); sbwash_dike (dikes); sbw_structure, (structural point data); and sbwash_carto (cartographic elements, geologic unit annotation and leaders). Geospatial entities in ARC/INFO coverages have the following software-defined attributes: <cover>.pat contains AREA, PERIMETER, cover#, and cover-ID; <cover>.aat contains FNODE#, TNODE#, LPOLY#, RPOLY#, LENGTH, cover#, and cover-ID. User-defined attributes are described in detail below.
    (1) The coverage sbwash_geo includes the following feature tables: (a) A polygon attribute table (sbwash_geo.pat) that lists labels for the geological characteristics and identifies plot labels for the rock units represented in the Postscript (.ps) and Portable Document Format (.pdf) plotfiles of the geologic maps; (b) Region subclass attribute tables that describe the geospatial distribution of rock units represented in the Postscript (.ps) and Portable Document Format (.pdf) plotfiles of the geologic maps (sbwash_geo.patrockunit), the hierarchical array of stratigraphic parents of rock units in the crystalline basement (sbwash_geo.patbasement1, sbwash_geo.patbasement2, sbwash_geo.patbasement3, sbwash_geo.patbasement4), the hierarchical array of stratigraphic parents of rock units in sedimentary and volcanic cover to the basement rocks (sbwash_geo.patcover2), and the hierarchical array of stratigraphic parents of surficial units (sbwash_geo.patsurficial1, sbwash_geo.patsurficial2, sbwash_geo.patsurficial3, sbwash_geo.patsurficial4, sbwash_geo.patsurficial5). This hierarchy of stratigraphic units can be related in ArcInfo, ArcMap or ArcView to display or plot more generalized, derivative geologic maps than that represented in Postscript (.ps) or Portable Document Format (.pdf) files. (c) A region subclass attribute table that describes surface units (veneers) (sbwash_geo.patsurfunit). (d) A region subclass attribute table that shows those areas where unit identification is uncertain (sbwash_geo.patident). (e) An arc attribute table (sbwash_geo.aat) that describes the contacts that bound rock-unit polygons.
    (2) The coverage sbwash_flt contains and displays the complete distribution of fault features within the extent of the San Bernardino Wash quadrangle. Structural line ornamentation is included in this layer as point data. Faults are characterized in two route attribute tables (sbwash_flt.ratsegment and sbwash_flt.ratfault).
    (3) The coverage sbwash_dike includes an arc attribute table (sbwash_dike.aat) that describes hypabyssal dikes. Dikes are planar intrusive features that intersect the Earth's surface as linear features; they are represented as lines where their surface widths are too narrow to be represented as areal features at a scale of 1:24,000.
    (4) The coverages sbw_structure includes a point attribute tables (sbw_structure.pat) that describe geologic structural point data, including the types and orientation of bedding and foliation. An annotation subclass (anno.dip - planar data) displays the dip values associated with each point datum.
    (5) The coverage sbwash_carto includes both geologic unit symbol annotation and an arc attribute table (sbwash_carto.aat) that displays annotation leaders. Unit symbols placed outside the perimeter of a particular polygon are identified by annotation leaders.
    Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/of/2002/0498/pdf/sbwash_pamph.pdf
    sbwash_geo.pat
    Polygon attribute table that stores alphanumeric symbols for units that characterize lithologic type, surface veneer, landform, and age of earth materials represented by each polygon. In addition, the table stores coded stratigraphic unit symbols.
    POLY_LABEL
    List of alphanumeric symbols that describe geologic characteristics of earth materials represented by each polygon: this attribute is used for data entry.
    Map units are described in region feature subclasses.
    SURF_LABEL
    Alphanumeric symbol for surface material represented by polygon (unique in this dataset).
    ROCK_LABEL
    Alphanumeric symbol for rock unit represented by polygon (unique in this dataset)
    POLY_IDENT
    An expression of confidence that a map unit represented by a particular polygon has been correctly identified (certain, likely, or questionable)
    GMPH_LABEL
    Alphanumeric symbol for geomorphic unit represented by polygon (unique in this dataset).
    PLOT_LABEL
    Coded symbols used to plot label of geologic units shown on geologic map in Postscript (.ps) and Portable Document Format (.pdf) files. Item can be related to data table, display.plt.
    sbwash_geo.patrockunit
    Geologic units contained in the database that are displayed on the geologic map in the Postscript (.ps) and Portable Document Format (.pdf) files
    UNIT_LABEL
    Rock-unit label
    ValueDefinition
    JmiMafic and intermediate intrusive suite (Middle or Early Jurassic)
    JqlQuartz latite (Late Jurassic)
    JsbeQuartz monzonite, monzogranite, and granodiorite, equigranular (Middle Jurassic)
    JsbpPorphyritic quartz monzonite, monzogranite, and granodiorite of San Bernardino Wash (Middle Jurassic)
    PridDolomite of Iron Chief mine (Middle or Early Proterozoic)
    PrpqglQuartzite of Pinto Mountain, light gray unit (Middle or Early Proterozoic)
    PrpqpQuartzite of Pinto Mountain, pelitic unit (Middle or Early Proterozoic)
    PrpqwQuartzite of Pinto Mountain, white unit (Middle or Early Proterozoic)
    QTcqConglomerate, quartzite-clast (Pleistocene and (or) Pliocene)
    QTsuSedimentary deposite, undivided (Pleistocene and (or) Pliocene)
    Qoam1Old alluvial deposits, middle unit 1 (middle and early Pleistocene)
    Qoam2Old alluvial deposits, middle unit 2 (middle? Pleistocene)
    Qoam3Old alluvial deposits, middle unit 3 (late Pleistocene)
    QoayOld alluvial deposits, young unit (Holocene and (or) Pleistocene)
    Qoc3Old colluvial deposits, Unit 3 (Pleistocene)
    QocuOld colluvial deposits, undivided (Pleistocene)
    QvoaVery old alluvial deposits (early Pleistocene)
    Qvya1Very young alluvial deposits, Unit 1 (late Holocene)
    Qvya2Very young alluvial deposits, Unit 2 (late Holocene)
    QvyauVery young alluvial deposits, undivided (late Holocene)
    QvyyeVery young and (or) young eolian deposits (Holocene)
    QvyypVery young and (or) young playa deposits (Holocene)
    Qyamg1Young alluvial deposits, middle gravelly facies 1 (middle Holocene)
    Qyamg2Young alluvial deposits, middle gravelly facies 2 (middle Holocene)
    QyamsYoung alluvial deposits, middle sandy facies (middle Holocene)
    QyamuYoung alluvial deposits, middle unit, undivided (middle Holocene)
    QyaogYoung alluvial deposits, old gravelly facies (middle and (or) early Holocene)
    QyaosYoung alluvial deposits, old oxidized sandy unit (middle and (or) early Holocene and late Pleistocene?)
    QyauYoung alluvial deposits, undivided (Holocene)
    QyaymuYoung alluvial deposits, young and middle units, undivided (late and middle Holocene)
    QyaysYoung alluvial deposits, young sandy facies (late and (or) middle Holocene)
    QyayuYoung alluvial deposits, young unit, undivided (late and (or) middle Holocene)
    TsSedimentary deposits (late and (or) middle Mioocene)
    TbBasalt (late and (or) middle Miocene
    TJduDike rocks, undivided (Tertiary, Cretaceous, and (or) Jurassic)
    sbwash_geo.patbasement1
    First-order stratigraphic parents of crystalline basement rock units
    UNIT_LABEL
    Rock-unit label
    ValueDefinition
    JmiMafic and intermediate intrusive suite (Middle or Early Jurassic)
    JsbQuartz monzonite, monzogranite, and granodiorite of San Bernardino Wash (Middle Jurassic)
    PrpqgQuartzite of Pinto Mountain, gray unit (Middle or Early Proterozoic)
    sbwash_geo.patbasement2
    Second-order stratigraphic parents of crystalline basement rock units
    UNIT_LABEL
    Rock-unit label
    ValueDefinition
    PrpqQuartzite of Pinto Mountain (Middle or Early Proterozoic)
    sbwash_geo.patbasement3
    Third-order stratigraphic parents of crystalline basement rock units
    ROCK_LABEL
    Rock-unit label
    ValueDefinition
    PremsMetasedimentary rocks of Eagle Mountains assemblage (Middle or Early Proterozoic)
    sbwas_geo.patbasement4
    Fourth-order stratigraphic parents of crystalline basement rock units
    UNIT_LABEL
    Rock-unit label
    ValueDefinition
    PreEagle Mountains assemblage (Proterozoic)
    sbwash_geo.patsurficial1
    First-order stratigraphic parents of surficial rock units
    UNIT_LABEL
    Rock-unit label
    ValueDefinition
    QyamgYoung alluvial deposits, middle gravelly facies (middle Holocene)
    sbwash_geo.patsurficial2
    Second-order stratigraphic parents of surficial rock units
    UNIT_LABEL
    Rock-unit label
    ValueDefinition
    QyayYoung alluvial deposits, young unit (late and (or) middle Holocene)
    QyamYoung alluvial deposits, middle unit (middle Holocene)
    QyaoYoung alluvial deposits, old unit (middle and (or) early Holocene)
    QoamOld alluvial deposits, middle unit (Pleistocene)
    QocOld colluvial deposits (Pleistocene)
    sbwash_geo.patsurficial3
    Third-order stratigraphic parents of surficial rock units
    UNIT_LABEL
    Rock-unit label
    ValueDefinition
    QvyaVery young alluvial deposits, middle unit (late Holocene)
    QyaYoung alluvial deposits (Holocene and late Pleistocene?)
    QoaOld alluvial deposits (Holocene? and Pleistocene)
    sbwash_geo.patsurficial4
    Fourth-order stratigraphic parents of surficial rock units
    UNIT_LABEL
    Rock-unit label
    ValueDefinition
    QvyyaVery young and young alluvial deposits (Holocene)
    QovoaOld and very old alluvial deposits (Pleistocene)
    sbwash_geo.patsurficial5
    Fifth-order stratigraphic parents of surficial rock units
    UNIT_LABEL
    Rock-unit label
    ValueDefinition
    QaAlluvial deposits (Quaternary)
    QcColluvial deposits (Quaternary)
    sbwash_geo.patcover2
    Second-order stratigraphic parents of cover rock units
    UNIT_LABEL
    Rock-unit label
    ValueDefinition
    QTsSedimentary deposits (Pleistocene and (or) Pliocene)
    sbwash_geo.patsurfunit
    Surface units (veneers)
    UNIT_LABEL
    Surface unit label
    ValueDefinition
    QvyyeDiscontinuous Qvyye veneer on mapped unit
    QyamsDiscontinuous Qyams veneer on mapped unit
    QyamuChanneled domains Qyamu subequal in areal extent to domains of mapped unit
    QyaogChanneled domains Qyaog subequal in areal extent to domains of mapped unit
    sbwash_geo.patident
    Confidence in rock-unit identification
    UNIT_IDENT
    An expression of confidence that the rock unit areas encompassed by the region have been identified correctly.
    ValueDefinition
    questionableIdentity of unit is attributed as questionable where unit assignment based on interpretation of aerial photographs is uncertain.
    sbwash_geo.aat
    Geologic contacts, including fault contacts, that bound rock-unit polygons and map boundary
    CLASS_TYPE
    Classification of contact by type
    ValueDefinition
    cartographic, map boundaryThe map boundary forms part of the perimeter of polygons that occur along the margins of the map.
    contactBoundary between two rock units; formed as fault, intrusive border, bedding plane, or unconformity
    facies boundaryIntra-unit lithologic boundary between coeval deposits derived either from different source terranes or from different drainage basins in the same source terrane
    fault-line scarpSteep slope formed by differential erosion along a fault line
    CLASS_ORIG
    Classification of contact by origin
    MOD_SEQ
    Sequence of processes by which contact has been modified
    CLASS_ALT
    Alternative classifiction of type of contact
    AGE_PREF
    Preferred age of contact
    AGE_LINEAGE
    Hierarchical age list of linear feature
    DESCRIPTION
    Contact description
    SYMB
    Coded integer symbol that relates arc to cartographic line symbol in lineset (geoscamp2.lin)
    DEFINITION
    Degree to which contact is discrete
    EXPOSURE
    An expression of how well a contact is represented by a line (discrete or nondiscrete)
    SOURCE_DATA
    Data source for contact
    sbwash_flt.aat
    Faults
    CLASS_TYPE
    Classification of line by type (fault)
    ValueDefinition
    faultSurface or zone of surfaces separating two bodies of rock and across which one body has slid past the other
    CLASS_ALT
    Alternative classification of fault
    EXPOSURE
    Degree to which fault is exposed
    LOCATION
    Accuracy of horizontal position of fault on input base map
    SYMB
    Coded integer symbol that relates arc to cartographic line symbol in lineset (geoscamp2.lin)
    sbwash_flt.ratsegment
    Fault segments: Arcs between or extending from fault intersections
    FLT_SEG
    Unique identification of fault segment
    ANGLE
    Classification by angle of dip
    SEPARATION
    Classification by separation on fault segments
    SLIP
    Classification by slip on fault segment
    AGE
    Age interval during which movement has occurred along fault segment
    BASIS
    Basis for representation of fault segment
    CONFIDENCE
    An expression of confidence that a fault segment has been correctly identified
    SOURCE
    Data source for fault segment
    sbwash_flt.ratfault
    Faults, fault strands, fault zones, fault systems, and fault groups
    SEPARATION
    Classification by separation on fault, fault strand, fault zone, fault system or fault group
    SLIP
    Classification by slip on fault, fault strand, fault zone, fault system or fault group
    AGE
    Age interval during which movement occurred on fault, fault strand, fault zone, fault system or fault group
    FLTNAME
    Name of fault, fault strand, fault zone, fault system or fault group
    MECH_REG
    Classification of fault by mechanical regime
    KINEM_REG
    Classification of fault by kinematic regime
    TECT_GEN
    Genetic classification of fault by tectonic system
    FLT_DESC
    Description of fault, fault strand, fault zone, fault system or fault group
    sbwash_dike.aat
    Dikes
    SYMB
    Coded integer symbol that relates arc to cartographic line symbol in lineset (geoscamp2.lin)
    UNIT_LABL
    Rock-unit label
    ValueDefinition
    JqlQuartz latite (Jurassic)
    TJduDike rocks, undivided (Tertiary, Cretaceous, or Jurassic)
    sbw_structure.pat
    Planar structural point data showing bedding and foliation orientation (strike, dip, direction of dip)
    ru_summ.dsc
    INFO table that summarizes name, age, origin, and lithology of rock units.
    UNIT_LABEL
    Alphanumeric symbol
    UNIT_NAME
    Name of rock unit
    AGEPAR_LS
    List of age names in parent lineage of rock unit stratigraphic age indicated in unit label
    AGE_LABEL
    Name of stratigraphic age of rock unit indicated in unit label
    AGECHLD_LS
    List of names in child lineage of rock unit stratigraphic age indicated in unit label
    ARCH_LEVEL
    Present-day architectural level of rock unit (crystalline basement, cover, surficial deposit, surface veneer)
    ENVIR_ORIG
    Hierarchical list of classification terms for origin and environment of formation of rock unit
    UNIT_TYPE
    Type of rock unit
    ROCK_FORM
    Form or landform of rock unit body
    LITH_GROUP
    List of parent lithologic groups to which rock unit belongs
    LITH_PRINC
    Principal lithologic components of rock unit
    LTH_SUBORD
    Subordinate lithologic components of rock unit
    LITH_MINOR
    Minor lithologic components of rock unit
    display.plt
    Data table that stores display criteria and data (rock unit colors/SHD, patterns/SHDFIL) to facilitate plotting of derivative maps. Symbolsets are: scamp2.shd (colors), geology2.shd (patterns).
    overlay.lut
    Data (lookup) table that stores symbols that allow surface veneers to be represented as pattern overlays.
    sbwash_carto.aat
    Annotation leaders and rock_unit labels derived from sbwash_geo.pat, plot_label

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Robert E. Powell
  2. Who also contributed to the data set?
    The digital data set was prepared by Pamela Cossette.
    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 Scott Graham has allowed us to further improve the digital database.
  3. To whom should users address questions about the data?
    Robert E. Powell
    U.S.Geological Survey, Western Region, Earth Surface Processes Team
    Project geologist
    U.S. Geological Survey
    Room 202
    West 904 Riverside Avenue
    Spokane, Washington
    USA

    (509) 368-3120 (voice)
    (509) 368-3199 (FAX)
    rpowell@usgs.gov

Why was the data set created?

The data set for the San Bernardino 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 Geological Survey. The San Bernardino 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 San Bernardino 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 San Bernardino 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 San Bernardino 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 the Pinto Basin.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 1973 (process 1 of 8)
    Geologic mapping for Ph.D. dissertation (Powell, 1981), supported in part by U.S. Geological Survey Earthquake Hazards Program, and in part by the National Science Foundation grants (EAR 76-23153 and EAR-74-00155) awarded to Leon T. Silver at the California Institute of Technolgy. Bedrock units and faults mapped in field on 1:36,000 true-color aerial photographs (USGS, 1973), compiled onto a 1:62,500 topographic base map of the Pinto Basin 15' quadrangle (1963, paper copy), then reduced onto a 125,000 topographic base (base-stable mylar greenline). Bedrock units in the Pinto Basin quadrangle were mapped, described, and interpreted by conducting field traverses and interpolating between the traverses by interpretation of aerial photographs. This mapping was part of a regional study of the geology and structure of the eastern Transverse Ranges province south of the Pinto Mountain fault.
    Powell, R.E., 1981, Geology of the crystalline basement complex, eastern Transverse Ranges, southern California: Constraints on regional tectonic interpretation [Ph.D. thesis]: Pasadena, California Institute of Technology, 441 p.
    USGS, 1973, True color aerial photographs labeled GS-SE. Photographs taken along northwest-southeast oriented flight lines covering the eastern Transverse Ranges south of the PInto Mountain fault. Lines flown at moderate to low sun-angle in October 1973; scale 1:36,000.
    Date: 1982 (process 2 of 8)
    Additional observations were made in bedrock units of the Pinto Basin quadrangle during the course of ongoing geologic studies in the eastern Transverse Ranges province (Powell, 1993).
    Powell, R.E., 1993, Balanced palinspastic reconstruction of pre-late Cenozoic paleogeology, southern California: Geologic and kinematic constraints on evolution of the San Andreas fault system, in Powell, R.E., Weldon, R.J., II, and Matti, J.C., eds., The San Andreas fault system: Displacement, palinspastic reconstruction, and geologic evolution: Geological Society of America Memoir 178, p. 1-106.
    Date: 1997 (process 3 of 8)
    The geologic map and database for the San Bernardino Wash quadrangle was generated by combining the bedrock mapping of previous process-steps with new, larger-scale mapping both of bedrock units and surficial deposits. The new mapping is based chiefly on interpretation of 1:24,000 color photographs (USGS, 1998), 1:40,000 NAPP infrared color photographs (USGS, 1996), and 1:80,000 NHAP infrared color photographs (USGS, 1983-1984) with minimal new fieldwork at this stage. Using ARCVIEW and its Image Analysis extension, geologic contacts, faults, and dikes were mapped on georeferenced USGS digital orthophotograph quarter quadrangles (DOQQs). The lines generated in ARCVIEW were assigned basic attributes and exported to ARCINFO where a line-polygon coverage was generated for the geology layer. This coverage was exported back to ARCVIEW as line and polygon shape files. Polygons were assigned their basic attributes in ARCVIEW and re-exported to ARCINFO for more complete attribution in the full coverage. Polygons in the coverage are attributed to generate the plot-file map. These plot-file map units, as well as other mapped units and aggregates of units that are included in the database but not shown on the plot-file map, are further attributed as region features (groups of polygons). Polygons were aggregated into regions to facilitate the identification, description and subsequent display of either individual rock units or stratigraphic groups of units at various hierarchical levels. Arcs representing fault segments were transferred to a separate coverage and aggregated into routes.
    USGS, 1998, True color aerial photographs labeled J.T.N.P. Photographs taken along east-west oriented flight lines covering part of Joshua Tree National Park in Pinto Basin and parts of the Coxcomb, Pinto, Eagle, Cottonwood, Hexie, and Little San Bernardino Mountains. Lines flown at high sun-angle in May 1998; scale 1:24,000.
    Date: 2000 (process 4 of 8)
    The source of the base hypsography, hydrography, and culture for the geologic map is the U.S. Geological Survey, 1:24,000-scale topographic map of the San Bernardino Wash 7.5 minute quadangle (provisional edition, 1986). The topographic map was photographically reproduced on scale-stable clear film. The resulting blackline photo-positive image was scanned at 500 dpi using an Anatech Eagle 4080 monochrome 800 dpi rasterizing scanner. The raster scan was imported into ARC/INFO, registered and rectified to the San Bernardino Wash quadrangle, and saved in GEOTIFF format. Topographic elements on the base map are geospatially located by this process, but no features are attributed. The topographic base map is provided for locational reference only.
    Date: 2002 (process 5 of 8)
    To provide a topographic base for the geologic map, the monochromatic raster scan file and the geologic map coverages were converted to ARC/INFO grids, and merged, resulting in the topographic and cultural information drawn in gray and the geologic map unit colors drawn with their respective colors. The combined map is a digital image in which geologic and topographic lines and points are displayed in their proper geospatial locations, but for which no information other than location is attached to the lines and points.
    Date: 2002 (process 6 of 8)
    Locations of foliation and bedding measurements were transferred from 1:24,000 unpublished field maps of R.A. Hope (University of California, Los Angeles, 1964-1966) to stable-base greenline of the San Bernardino Wash 7.5 minute quadrangle and digitized using an Altek Datatab digitizer. Measurement attributes of Hope's data were entered from azimuths recorded in field notes, where available, or by measuring azimuths from strike-and-dip symbols on his maps.
    Date: 25-Apr-2002 (process 7 of 8)
    First draft of metadata created by Cossette using FGDCMETA.AML ver. 1.2 05/14/98 on ARC/INFO data set /pool5/pool1/cossette/1_joshua/1_sbw/sbw0425a
    Date: 09-Sep-2003 (process 8 of 8)
    Creation of original metadata record Person who carried out this activity:
    U.S. Geological Survey
    Attn: Pamela M. Cossette
    Geographer
    U.S. Geological Survey
    West 904 Riverside Avenue
    Spokane, Washington
    USA

    509-368-3123 (voice)
    509-368-3199 (FAX)
    pcossette@usgs.gov
  3. What similar or related data should the user be aware of?
    Powell, Robert E., 2002, Geologic map and digital database of the Pinto Mountain 7.5 minute quadrangle, Riverside County, California: U.S. Geological Survey Open-File Report 02-491, U.S. Geological Survey, Menlo Park, California.

    Online Links:

    Powell, Robert E., 2001, Geologic map and digital database of the Porcupine Wash 7.5 minute quadrangle, Riverside County, California: U.S. Geological Survey Open-File Report 01-030, U.S. Geological Survey, Menlo Park, California.

    Online Links:

    Powell, Robert E., 2001, Geologic map and digital database of the Conejo Well 7.5 minute quadrangle, Riverside County, California: U.S. Geological Survey Open-File Report 01-031, U.S. Geological Survey, Menlo Park, California.

    Online Links:


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    This initial version of the San Bernardino Wash geologic map database relies extensively on interpretation of aerial photographs; field study of bedrock units was conducted in the context of smaller-scale regional mapping and field study of surficial deposits has been minimal. The map represents the state of knowledge for the quadrangle and provides a basis for gathering additional field data to resolve questions raised in making the map. Attributes assigned to regions, polygons, lines, and points in the San Bernardino Wash database are reasonably accurate as determined by the normal range of checks and balances applied in making a geologic map by a combination of hands-on and remote field observation, sampling, and interpretation of aerial photographs. Additional field investigation, however, is required to verify the accuracy of polygon (map unit) attributes and to establish relations among units. Where anomalous descriptive characteristics lead to particular uncertainty of unit assignment of a polygon, the polygon is included within the region feature subclass IDENT, where it is assigned a value of "questionable" in the item UNIT_IDENT. In the San Bernardino Wash quadrangle, this attribution has been used chiefly for unit assignments of unvisited polygons that appear anomalous on aerial photographs.
  2. How accurate are the geographic locations?
    Geologic lines are considered to be accurately located if the linear geologic features that they represent are discrete, well exposed, and the horizontal location of the line representing the feature is judged to lie within limits defined by national map accuracy standard. These standards are 1/50 in or +/-40 ft (12 m) for features located on 1:24,000 scale topographic maps and 1/30 in or +/-33.3 ft (10 m) for features located on 1:12,000 scale digital orthophotograph quarter quadrangles (DOQQs). Linear features are considered discrete if they are sharply defined with a width less than or equal to 1/100 in at scale of map (20 ft for features located on 1:24,000 scale topographic maps and 10 ft for features located on 1:12,000 scale DOQQs).
    Geologic lines that are not discrete (e.g., gradational or transitional contacts), are not well exposed, or cannot be located within the limits defined by the national map accuracy standard are considered to be approximately located. Linear features in the San Bernardino geologic map database are represented as solid, dashed, and dotted lines. Using a DOQQ base, linear features represented by solid lines are located to within 33.3 ft (10 m) or less of their position on the ground. Linear features represented as dashed or dotted lines may or may not be located to within 10 m of their position on the ground. Linear features represented by dotted lines are concealed beneath overlying mapped units.
    The accuracy of point features in the San Bernardino Wash database is +/-10 ft for points located on the DOQQ base, +/-33 ft for points located on a 1:24,000-scale topographic base, and +/-52 ft for points located on a 1:62,000-scale topographic base. Contacts between lithologic domains that make up surficial deposits as mapped on the DOQQs typically are readily located to within 10 m, but to make domains that can be resolved at 1:24,000 contacts are often drawn by approximating the dominant unit on a percentage basis. Interspersal of well- and approximately located segments is common among the many thousands of contacts present in the San Bernardino Wash quadrangle. Given that many quadrangles are being mapped in a relatively short time interval, it was deemed too time-consuming to distinguish well-located and approximately located contacts between surficial deposits; therefore, all surficial contacts are represented as approximately located and shown with a dashed line symbol.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    The geologic map and digital database of the San Bernardino Wash 7.5 minute quadrangle contain new data that have been subjected to rigorous review and are a substantially complete representation of the current state of knowledge concerning the geology of the quadrangle.
  5. How consistent are the relationships among the observations, including topology?
    Polygon and chain-node topology present.
    The areal extent of the map is represented digitally by an appropriately projected (Polyconic projection), mathematically generated box. Consequently, polygons intersecting the lines that comprise the map boundary are closed by that boundary. Polygons internal to the map boundary are completely enclosed by line segments which are themselves a set of sequentially numbered coordinate pairs. Point data are represented by coordinate pairs.

How can someone get a copy of the data set?

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 San Bernardino 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 San Bernardino 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 San Bernardino 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 San Bernardino 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.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey Information Services
    Box 25286 Denver Federal Center
    Denver, CO
    USA

    303-202-4700 (voice)
    303-202-4693 (FAX)
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    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 San Bernardino 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.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 10-Jun-2016
Metadata author:
Peter N Schweitzer
USGS Midwest Area
Collection manager, USGS Geoscience Data Clearinghouse, http://geo-nsdi.er.usgs.gov/
Mail Stop 954
12201 Sunrise Valley Dr
Reston, VA
USA

703-648-6533 (voice)
703-648-6252 (FAX)
pschweitzer@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://geo-nsdi.er.usgs.gov/metadata/open-file/02-498/metadata.faq.html>
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