Geologic Map of the Sunnymead 7.5' Quadrangle, Riverside County, California

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What does this data set describe?

Geologic Map of the Sunnymead 7.5' Quadrangle, Riverside County, California
This data set maps and describes the geology of the Sunnymead 7.5' quadrangle, Riverside County, California. Created using Environmental Systems Research Institute's ARC/INFO software, the data base consists of the following items: (1) a map coverage containing geologic contacts and units, (2) a coverage containing structural data, (3) a coverage containing geologic unit annotation and leaders, and (4) attribute tables for geologic units (polygons), contacts (arcs), and site-specific data (points). In addition, the data set includes the following graphic and text products: (1) a postscript graphic plot-file containing the geologic map, topography, cultural data, a Correlation of Map Units (CMU) diagram, a Description of Map Units (DMU), and a key for point and line symbols, and (2) PDF files of the Readme (including the metadata file as an appendix), and the graphic produced by the Postscript plot file.
The Sunnymead quadrangle is located in the northern part of the Peninsular Ranges Province and is underlain by Cretaceous and older basement rocks. This part of the Peninsular Ranges Province is divided into the Perris block, located west of the San Jacinto fault and the San Jacinto Mountains block to the east. The northwest quarter of the quadrangle is crossed diagonally by the San Jacinto fault zone, an important active major fault of the San Andreas fault system. The San Jacinto fault zone consist of a main trace and multiple discontinuous breaks. The main trace forms a dissected, west-facing fault scarp about 1,000 feet above the valley floor. A vaguely located fault in granitic rocks parallel to and west of the San Jacinto fault zone does not appear to cut Pleistocene age alluvial deposits.
On the northern side of the San Jacinto fault zone is a thick section of Pliocene and Pleistocene continental sedimentary rocks, the upper part of the San Timoteo beds of Frick(1921). The area underlain by these rocks is termed the San Timoteo Badlands. Most of these beds consist of coarse-grained sandstone, conglomeratic sandstone, and conglomerate. All the clasts within these beds were derived from Transverse Ranges basement rocks that are located to the north of the quadrangle. The San Timoteo beds have been deformed into a broad anticlinal structure produced by the sedimentary beds being compressed as they are translated around a restraining bend in the San Jacinto fault north of the El Casco quadrangle. A curving, diachronous fault produced by this compression is located in the western part of the badlands just east of the San Jacinto fault zone.
The area west of the San Jacinto fault zone is underlain by plutonic rocks of the Cretaceous-age Peninsular Ranges batholith with a few small included pendants of schist and gneiss of probable Paleozoic age. Most of the plutonic rocks are of tonalite composition and are mainly biotite-hornblende tonalite. In the northwestern part of the quadrangle is the eastern part of the Box Springs granitic complex, a basinal-shaped complex that appears to be the distal part of a diapiric-shaped complex.
Most of the alluviated area west of the San Jacinto fault zone consists of Pleistocene age fluvial deposits. Most of these deposits have a degraded upper surface. The upper surface of these deposits are preserved in some places near the contact with granitic rocks. The upper part of these deposits form the Paloma surface of Woodford and others(1971). Holocene age alluvial fans emanate from the San Timoteo Badlands.
The geologic map data base contains original U.S. Geological Survey data generated by detailed field observation recorded on 1:24,000 scale aerial photographs. The map was created by transferring lines from the aerial photographs to a 1:24,000 scale topographic base. The map was digitized and lines, points, and polygons were subsequently edited using standard ARC/INFO commands. Digitizing and editing artifacts significant enough to display at a scale of 1:24,000 were corrected. Within the database, geologic contacts are represented as lines (arcs), geologic units are polygons, and site-specific data as points. Polygon, arc, and point attribute tables (.pat, .aat, and .pat, respectively) uniquely identify each geologic datum.
  1. How might this data set be cited?
    Morton, Douglas M., and Matti, Jonathan C., 2001, Geologic Map of the Sunnymead 7.5' Quadrangle, Riverside County, California: U.S. Geological Survey Open-File Report 01-450, U.S. Geological Survey, Menlo Park, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -117.25009155
    East_Bounding_Coordinate: -117.12490863
    North_Bounding_Coordinate: 34.00000057
    South_Bounding_Coordinate: 33.87498338
  3. What does it look like? (PDF)
    Printable map sheet, 1.4 megabytes.
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2001
    New data obtained
  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 (440)
      • String (1261)
      • GT-polygon composed of chains (441)
    2. What coordinate system is used to represent geographic features?
      The map projection used is Polyconic.
      Projection parameters:
      Latitude_of_Projection_Origin: 33.875
      Longitude_of_Central_Meridian: -117.1875
      False_Easting: 0.00000
      False_Northing: 0.00000
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 1.000396490097
      Ordinates (y-coordinates) are specified to the nearest 1.000396490097
      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?
    Version 1.0 of the Sunnymead 7.5' quadrangle comprises three ARC/INFO coverages, of which two contain geologic data, and one contains cartographic features: sun_geo (geology), sun_str (structural data), and sun_ano (annotation and leaders).
    Geologic data represented by line entities and the polygons they delineate are contained in the coverage SUN_GEO. For display purposes, the annotation coverage contains one annotation subclass: anno.geo contains unit labels.
    Geological point data includes site-specific information describing the types and the orientation of bedding, foliation, and lineations. Annotation is respective dip and plunge values associated with individual point data.
        1  AREA                   4    12     F      3
        5  PERIMETER              4    12     F      3
        9  SUN_GEO#               4     5     B      -
       13  SUN_GEO-ID             4     5     B      -
       17  LABL                  35    35     C      -
       52  PLABL                 35    35     C      -
       87  SHD                    3     3     I      -
       90  SHDFIL                 3     3     I      -
       93  NAME                 200   200     C      -
        1  FNODE#                 4     5     B      -
        5  TNODE#                 4     5     B      -
        9  LPOLY#                 4     5     B      -
       13  RPOLY#                 4     5     B      -
       17  LENGTH                 4    12     F      3
       21  SUN_GEO#               4     5     B      -
       25  SUN_GEO-ID             4     5     B      -
       29  LTYPE                 35    35     C      -
       64  L-SYMB                 3     3     I      -
    Geologic units (LABL) and their corresponding names (NAME) identified in the Sunnymead 7.5' quadrangle
    geologic map unit label, in plain text
    KbftBiotite-hornblende tonalite of Box Springs plutonic complex
    KbgPorphyritic granodiorite of Box Springs plutonic complex
    KbhgHeterogeneous porphyritic granodiorite of Box Springs plutonic complex
    KgGranitic dikes
    KguGranite, undifferentiated
    KhgHeterogeneous granitic rocks
    KqdQuartz diorite, undifferentiated
    KtTonalite, undifferentiated
    KtmTonalite and mafic rocks, undifferentiated
    PzsBiotite schist
    QTstcQuartzite-bearing conglomerate beds of San Timoteo beds of Frick (1921)
    QTstsConglomeratic sandstone beds of San Timoteo beds of Frick (1921)
    QTstuUpper member of San Timoteo beds of Frick (1921)
    QaAxial channel deposits
    QafArtificial fill
    QfagAlluvial fan deposits, arenaceous gravel
    QlsLandslide deposits
    QofaOld alluvial fan deposits, arenaceous
    QofagOld alluvial fan deposits, arenaceous gravel
    QolsOld landslide deposits
    Qvof1aVery old alluvial fan deposits, unit 1, arenaceous
    QvofaVery old alluvial fan deposits, arenaceous
    QvolsVery old landslide deposits
    QwagWash deposits, arenaceous gravel
    QyaaYoung axial channel deposits, arenaceous
    QyaagYoung axial channel deposits, arenaceous gravel
    QyfaYoung alluvial fan deposits, arenaceous
    QyfagYoung alluvial fan deposits, arenaceous gravel
    QylsYoung landslide deposits
    QyvaYoung alluvial valley deposits, arenaceous
    QyvsaYoung alluvial valley deposits, silt arenaceous
    QywaYoung wash deposits, arenaceous
    QywagYoung wash deposits, arenaceous gravel
    TstdMiddle member conglomerate of San Timoteo beds of Frick (1921)
    TstmMiddle member of San Timoteo beds of Frick (1921)
    Geological map unit label used to generate plot labels with relevant stratigraphic symbols. The geologic units with LABL designating Mesozoic (Mz) have keystroke substitute characters, }, that call their corresponding symbols from the Stratagem Font Group. Geologic map unit labels will plot on derivative map plots with appropriate stratigraphic symbols if PLABL is used as the source for unit labels.
    polygon color (as integer value) from shadeset alc1.shd (included in the symbols package)
    polygon fill pattern (as integer value) from shadeset geology2.shd (included in the symbols package)
    Geologic name of map unit (see list under LABL attribute)
    Geologic features such as contacts and faults that bound rock-unit polygons
    Description of types of lines on the geologic map (contact, fault).
    contact, certain 
    fault, certain 
    fault, approx. located 
    fault, concealed 
    fault, queried 
    fault, approx. located, queried 
    Kg, granitic dike 
    map boundary 
    stores appropriate line symbol value from the lineset geoscamp2.lin
    Geological point data includes site-specific information describing the types and the orientation of bedding, foliation, and lineations. One annotation subclass is included in the geologic points coverage, SUN_STR which displays the respective dip and plunge values associated with individual point data.
    describes type of point data (bedding, horizontal bedding, foliation)
    Coded integer value that relates point to cartographic point symbol in markerset geoscamp2.mrk
    Azimuthal strike of planar feature
    Dip of planar feature
    Annotation leaders
    Coded integer value (1) that relates arcs to cartographic line symbol in lineset geoscamp2.lin

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Douglas M. Morton
    • Jonathan C. Matti
  2. Who also contributed to the data set?
    Geologic mapping and digital preparation of this report were sponsored jointly by (1) the National Cooperative Geologic Mapping Program of the U.S. Geological Survey, (2) the California Division of Mines and Geology, (3) the Southern California Areal Mapping Project (SCAMP), and (4) the U.S. Air Force.
  3. To whom should users address questions about the data?
    Douglas M Morton
    U.S. Geological Survey, GEO-WRG-NGM
    UC - Riverside
    Riverside, CA

    909-276-6397 (voice)
    909-276-6295 (FAX)

Why was the data set created?

The data set for the Sunnymead 7.5' quadrangle was prepared under the U.S. Geological Survey Southern California Areal Mapping Project (SCAMP) as part of an ongoing effort to develop a regional geologic framework of southern California, and to utilize a Geographic Information System (GIS) format to create regional digital geologic databases. These regional databases are being developed as contributions to the National Geologic Map Database of the National Cooperative Geologic Mapping Program of the USGS.

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: 1978 (process 1 of 6)
    Field mapping and aerial photograph interpretation; iterative process (D.M. Morton).
    Date: 1988 (process 2 of 6)
    Field mapping and aerial photograph interpretation; iterative process (J.C. Matti).
    Date: 1999 (process 3 of 6)
    Digitization of geologic linework and point data from a scale-stable cartographic base of quadrangle. ARC/INFO database established; cleanup of artifacts; polygon, arc, and point attribute tables established. Digitizing and editing artifacts significant enough to display at a scale of 1:24,000 were corrected (V.M. Diep and U. Edwards-Howells).
    Date: 2001 (process 4 of 6)
    Description of map units and correlation of map units (F.K. Miller).
    Date: 03-Oct-2001 (process 5 of 6)
    First draft of metadata created by Michael J. Watson using FGDCMETA.AML ver. 1.2 05/14/98 on ARC/INFO data set /scamp26/mwatson/sun_ofr/sun_geo
    Date: 03-Oct-2001 (process 6 of 6)
    Creation of original metadata record Person who carried out this activity:
    U.S. Geological Survey
    Attn: Rachel M.H. Alvarez
    U.S. Geological Survey
    Department of Earth Sciences
    University of California, Riverside
    Riverside, California

    (909) 276-6397 (voice)
    (909) 276-6295 (FAX)
  3. What similar or related data should the user be aware of?
    Morton, D.M., 1999, Preliminary digital geologic map of the Santa Ana 30'x60' quadrangle, southern California, version 1.0.: U.S. Geological Survey Open-File Report 99-172, U.S. Geological Survey, California.

    Online Links:

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

  1. How well have the observations been checked?
    Geologic-map units in the Sunnymead quadrangle database were described using standard field methods. Consistent with these methods, the database author has assigned standard geologic attributes to geologic lines, points, and polygons identified in the database.
    Nationwide geologic-map accuracy standards have not been developed and adopted by the U.S. Geological Survey and other earth-science entities. Until such standards are adopted, the SCAMP project has developed internal map-accuracy standards for 1:24,000-scale geologic maps produced by the project. Geologic lines and points on 1:24,000 scale geologic maps are judged to meet SCAMP's internal map-accuracy standards if they are located to within +/-15 meters, relative to topographic or cultural features on the base map. On any derivative geologic-map plot, line data that are judged to meet the SCAMP internal map-accuracy standard are denoted by solid lines; line data that may not meet the SCAMP internal map-accuracy standard are denoted by dashed or dotted lines. There is no cartographic device for denoting the map-accuracy for geologic-point data (e.g., symbols representing bedding, foliation, lineations, etc.).
  2. How accurate are the geographic locations?
    The maximum transformation RMS error acceptable for a 7.5' quadrangle transformation and data input is 0.003 (1.8 meters). Horizontal positional accuracy was checked by visual comparison of hard-copy plots with base-stable source data.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    The geologic map database of the Sunnymead 7.5' quadrangle contains 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
The Sunnymead 7.5' geologic-map database should be used to evaluate and understand the geologic character of the Sunnymead 7.5' quadrangle as a whole. The data should not be used for purposes of site-specific land-use planning or site-specific geologic evaluations. The database is sufficiently detailed to identify and characterize many actual and potential geologic hazards represented by faults and landslides and posed by ground subsidence and earthquake-generated ground shaking. However, 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 Hart, 1988).
Use of this digital geologic-map database 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 compiled and edited at a scale of 1:24,000 means that higher resolution information may not have been uniformly retained 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, although higher resolution data is incorporated in most of the map, the resolution of the combined output will be limited by the lower resolution data.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey Information Services
    Box 25286 Denver Federal Center
    Denver, Colorado

    (303)202-4700 (voice)
    (303)202-4693 (FAX)
  2. What's the catalog number I need to order this data set? USGS Open-File Report 01-450
  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 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 the delivery, installation, operation, or support by USGS.
    This digital geologic map database of the Sunnymead 7.5' quadrangle, 1:24,000 map-scale, and any derivative maps thereof, is not meant to be used or displayed at any scale larger than 1:24,000 (e.g., 1:12,000).
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: Geologic units and structural features, with TIFF image of base map in format ARCE (version 7.2.1) Size: 2.7
      Network links:
    • Cost to order the data: none

Who wrote the metadata?

Last modified: 10-Jun-2016
Metadata author:
Peter N Schweitzer
USGS Midwest Area
Collection manager, USGS Geoscience Data Clearinghouse,
Mail Stop 954
12201 Sunrise Valley Dr
Reston, VA

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

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