Geologic map of the Lockwood Valley quadrangle, Ventura County, California

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Frequently anticipated questions:


What does this data set describe?

Title:
Geologic map of the Lockwood Valley quadrangle, Ventura County, California
Abstract:
The Lockwood Valley quadrangle is located in the western Transverse Ranges of California, about 10 km southwest of Frazier Park. It includes the western flank of Frazier Mountain, southern Lockwood Valley, and a region of the Los Padres National Forest near northern Piru Creek.
The oldest rocks are mostly biotite augen gneiss, in the hanging wall of the Frazier Mountain thrust and in a large body south of the thrust. A U-Pb zircon age for the gneiss is 1690+5 Ma (W. Premo, unpublished data). Two Cretaceous intrusive rocks are named the quartz monzonite of Sheep Creek and the coarse-grained granodiorite of Lockwood Peak. A U-Pb zircon age on the latter is 76.05+0.22 Ma (W. Premo, unpublished data).
The northeastern edge of a large Eocene marine basin, comprising the sandstones, shales, and conglomerates of the Juncal Formation, occupies the southwestern 25 percent of the quadrangle. Miocene fluvial rocks, including coarse boulder conglomerates, sandstones, and shale, of the Caliente Formation crop out mostly in the northwestern part of the quadrangle. Commercially exploitable Lockwood Clay unconformably overlies the Caliente, which, in turn, is overlain by the mostly fluvial Pliocene Quatal Formation.
Two major south-directed thrusts, the Frazier Mountain thrust and the South Frazier Mountain thrust, place crystalline rocks over Miocene and Pliocene sedimentary rocks. The South Frazier Mountain thrust is transected by the newly recognized, north-directed Lockwood Peak reverse fault. In addition, the newly recognized south-directed Yellowjacket thrust displaces rocks of the Pliocene Quatal Formation.
Supplemental_Information:
Map political location: Ventura County, California Compilation scale: 1:24,000 Geology mapped in 1996 and 1997.
  1. How might this data set be cited?
    Kellogg, Karl S., 2001, Geologic map of the Lockwood Valley quadrangle, Ventura County, California: U.S. Geological Survey Open-File Report 99-130, U.S. Geological Survey, Denver, Colorado.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -119.125
    East_Bounding_Coordinate: -119.0
    North_Bounding_Coordinate: 34.75
    South_Bounding_Coordinate: 34.625
  3. What does it look like?
    http://pubs.usgs.gov/of/1999/ofr-99-0130/ofr-99-0130so.pdf (PDF)
    graphic representation of map layout
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2001
    Currentness_Reference:
    publication date
  5. What is the general form of this data set?
  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.
    2. What coordinate system is used to represent geographic features?
      The map projection used is Lambert Conformal Conic.
      Projection parameters:
      Standard_Parallel: 34.03333333333
      Standard_Parallel: 35.46666666667
      Longitude_of_Central_Meridian: -118.0
      Latitude_of_Projection_Origin: 33.5
      False_Easting: 0.00000
      False_Northing: 0.00000
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 10
      Ordinates (y-coordinates) are specified to the nearest 10
      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 data is supplied in ARC/INFO export and shape file formats.
    DATABASE STRUCTURE - ARC/INFO ====================================
    The database of the map consists of three coverages (root name = lw). This GIS database includes related look-up tables, which store detailed attribute information. Arc/Info relates for each coverage are saved in a file named <covername>.rel. Use the RELATE command with the restore argument at the arc prompt to make the relates active. Alternatively, in Arctools, use the Relate environment: open dialog in the Manage - Relates flyout menu under the Arctools menu to make the relates active.
    lwpoly coverage: Contains all contact lines and labelpoints for each geologic polygon. In the lwpoly.pat INFO file the LABEL item indicates the rock unit label (abbreviation) used to label the unit on the map. The DESC item contains the formal or informal unit name. The SOURCE item contains the numeric code used to identify the data source for the rock unit. The SYMBOL item contains the shadeset symbol number used by ArcInfo to plot a filled/shaded polygon. The symbol numbers in this coverage refer to the color524.shd shadeset.
    In the coverage's lwpoly.aat INFO file the NAME item contains the name given to the structural feature. The SOURCE item contains the numeric code used to identify the data source for the structural feature. The SYMBOL item contains the lineset symbol number used by ArcInfo to plot a line. The symbol numbers in this coverage refer to the geol_sfo.lin lineset.
    In the coverage's lwpoly.ref INFO file the SOURCE item lists the numeric code used to identify the data source. The scale item lists the scale of the source map. (This value is the denominator of the proportional fraction that identifies the scale of the map that was digitized or scanned to produce the digital map.) The AUTHORS item lists the author(s) or compiler(s) of source map entered as last name, first name or initial, and middle initial. The YEAR item lists the source (map) publication date. The REFERENCE item lists the remainder of the reference in USGS reference format.
    The INFO structure of these files is listed below:
    LWPOLY.PAT
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  AREA                   8    18     F      5
        9  PERIMETER              8    18     F      5
       17  LWPOLY#                4     5     B      -
       21  LWPOLY-ID              4     5     B      -
       25  SOURCE                 4     4     I      -
       29  LABEL                 10    10     C      -
       39  DESC                 100   100     C      -
      139  SYMBOL                 3     3     I      -
    LWPOLY.CON
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  LINECODE               3     3     I      -
        4  SYMBOL                 3     3     I      -
        7  TYPE                  10    10     C      -
       17  MODIFIER              20    20     C      -
       37  CERTAINTY             15    15     C      -
       52  DESC                 100   100     C      -
    LWPOLY.STR
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  LINECODE               3     3     I      -
        4  SYMBOL                 3     3     I      -
        7  TYPE                  10    10     C      -
       17  HORIZONTAL            20    20     C      -
       37  VERTICAL              20    20     C      -
       57  FOLD                  15    15     C      -
       72  PLUNGE                15    15     C      -
       87  ACCURACY              15    15     C      -
      102  CERTAINTY             15    15     C      -
      117  DESC                 100   100     C      -
    LWPOLY.AAT
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  FNODE#                 4     5     B      -
        5  TNODE#                 4     5     B      -
        9  LPOLY#                 4     5     B      -
       13  RPOLY#                 4     5     B      -
       17  LENGTH                 8    18     F      5
       25  LWPOLY#                4     5     B      -
       29  LWPOLY-ID              4     5     B      -
       33  LINECODE               3     3     I      -
       36  NAME                  30    30     C      -
       66  SOURCE                 4     4     I      -
       70  SYMBOL                 3     3     I      -
    LWPOLY.REF
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  SOURCE                 4     4     I      -
        5  SCALE                  8     8     I      -
       13  AUTHORS              200   200     C      -
      213  YEAR                   4     4     I      -
      217  REFERENCE            250   250     C      -
    
    lwline coverage: contains limit of overturned strata, cross-section lines, and a synclinal fold axis line. In the lwline.aat INFO file the NAME item indicates the name given to the structural feature. The SOURCE item contains the numeric code used to identify the data source for the structural feature. The DESC item contains the written description or explanation of the contact, boundary, or structural feature. The SYMBOL item contains the lineset symbol number used by ArcInfo to plot a line. The symbol numbers in this coverage refer to the geol_sfo.lin lineset.
    In the coverage's lwline.ref INFO file the SOURCE item lists the numeric code used to identify the data source. The scale item lists the scale of the source map. (This value is the denominator of the proportional fraction that identifies the scale of the map that was digitized or scanned to produce the digital map.) The AUTHORS item lists the author(s) or compiler(s) of source map entered as last name, first name or initial, and middle initial. The YEAR item lists the source (map) publication date. The REFERENCE item lists the remainder of the reference in USGS reference format.
    The INFO structure of these files is listed below:
    LWLINE.AAT
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  FNODE#                 4     5     B      -
        5  TNODE#                 4     5     B      -
        9  LPOLY#                 4     5     B      -
       13  RPOLY#                 4     5     B      -
       17  LENGTH                 8    18     F      5
       25  LWLINE#                4     5     B      -
       29  LWLINE-ID              4     5     B      -
       33  LINECODE               3     3     I      -
       36  NAME                  30    30     C      -
       66  SOURCE                 4     4     I      -
       70  DESC                 100   100     C      -
      170  SYMBOL                 3     3     I      -
    LWLINE.CON
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  LINECODE               3     3     I      -
        4  SYMBOL                 3     3     I      -
        7  TYPE                  10    10     C      -
       17  MODIFIER              20    20     C      -
       37  CERTAINTY             15    15     C      -
       52  DESC                 100   100     C      -
    LWLINE.STR
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  LINECODE               3     3     I      -
        4  SYMBOL                 3     3     I      -
        7  TYPE                  10    10     C      -
       17  HORIZONTAL            20    20     C      -
       37  VERTICAL              20    20     C      -
       57  FOLD                  15    15     C      -
       72  PLUNGE                15    15     C      -
       87  ACCURACY              15    15     C      -
      102  CERTAINTY             15    15     C      -
      117  DESC                 100   100     C      -
    LWLINE.REF
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  SOURCE                 4     4     I      -
        5  SCALE                  8     8     I      -
       13  AUTHORS              200   200     C      -
      213  YEAR                   4     4     I      -
      217  REFERENCE            250   250     C      -
    
    lwpnt coverage: Contains points recording site-specific observations and measurements, such as strike and dip of bedding. In the lwpnt.pat INFO file the PTTYPE item lists the type of point symbol, e.g., strike and of inclined bedding. The SYMBOLCD item lists the marker symbol used by ArcInfo to identify the type of structural map symbol. Symbol numbers refer to the geoscamp2.mrk markerset. The STRIKE item contains the strike of bedding. Strike is an azimuthal angle (measured in degrees from 0 to 360 in a clockwise direction from North). The DIP item contains the dip of bedding. This value is an angle measured (in degrees 0 to 90) down from the horizontal; thus a horizontal dip is 0 degrees and a vertical dip is 90 degrees. The BEARING item contains the bearing of lineation. Bearing is an azimuthal angle (measured in degrees from 0 to 360 in a clockwise direction from North). The PLUNGE item contains the plunge of lineation. This value is an angle measured (in degrees 0 to 90) down from the horizontal; thus a horizontal plunge is 0 degrees and a vertical plunge is 90 degrees. The CALCANG item contains an interim value used to calculate SYM$ANGLE. The SYM$ANGLE item is the angle used to mathematically rotate the map point symbol to its proper orientation on the map. This item was set equal to the pseudoitem '$ANGLE' (calc SYM$ANGLE = $ANGLE). The SOURCE item lists the numeric code used to identify the data source.
    In the coverage's lwpnt.ref INFO file the SOURCE item lists the numeric code used to identify the data source. The scale item lists the scale of the source map. (This value is the denominator of the proportional fraction that identifies the scale of the map that was digitized or scanned to produce the digital map.) The AUTHORS item lists the author(s) or compiler(s) of source map entered as last name, first name or initial, and middle initial. The YEAR item lists the source (map) publication date. The REFERENCE item lists the remainder of the reference in USGS reference format.
    The INFO structure of these files is listed below:
    LWPNT.PAT
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  AREA                   8    18     F      5
        9  PERIMETER              8    18     F      5
       17  LWPNT#                 4     5     B      -
       21  LWPNT-ID               4     5     B      -
       25  PTTYPE                80    80     C      -
      105  SYMBOLCD               3     3     I      -
      108  STRIKE                 3     3     I      -
      111  DIP                    3     3     I      -
      114  BEARING                3     3     I      -
      117  PLUNGE                 3     3     I      -
      120  CALCANG                4     4     I      -
      124  SYM$ANGLE              4     4     I      -
      128  SOURCE                 4     4     I      -
    LWPNT.REF
    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
        1  SOURCE                 4     4     I      -
        5  SCALE                  8     8     I      -
       13  AUTHORS              200   200     C      -
      213  YEAR                   4     4     I      -
      217  REFERENCE            250   250     C      -
    
    Auxiliary files:
    color524.shd: This shadeset file defines the rgb values of colors assigned to polygons in the lwpoly coverage (see SYMBOL item).
    geol_sfo.lin: This lineset file defines geologic line types in the geologically themed coverages.
    geoscamp2.mrk: This markerset file defines the geologic markers in the geologically themed coverages.
    LABEL	 DESC
    Qa	Alluvium (Holocene)
    Qc	Colluvium (Holocene)
    Qac	Alluvium, loess, and colluvium, undifferentiated (Holocene)
    Qls	Landslide deposits (Holocene)
    Qt	Talus (Holocene)
    Qdf	Debris-flow deposit (Holocene and upper Pleistocene)
    Qlo	Older landslide deposit (upper? Pleistocene)
    Qoa	Older alluvium (upper? Pleistocene)
    Qbd	Boulder diamicton (Pleistocene)
    Qhc	High-level conglomerate (lower? Pleistocene)
    Tqc	Quatal Formation, sandstone and conglomerate member (Pliocene)
    Tqs	Quatal Formation, sandstone and siltstone member (Pliocene)
    Tqa	Quatal Formation, arkosic member (Pliocene)
    Tqb	Quatal Formation, brown member (Pliocene)
    Tqg	Quatal Formation, green claystone and sandstone member (Pliocene)
    Tlc	Lockwood Clay (Pliocene or Miocene)
    Tc	Caliente Formation, undifferentiated (Miocene)
    Tcs	Caliente Formation, green claystone and sandstone member (Miocene)
    Tjm	Juncal Formation, mixed shale and sandstone member (Eocene)
    Tjs	Juncal Formation, sandstone member (Eocene)
    Tjc	Juncal Formation, conglomerate member (Eocene)
    Kgs	Quartz monzonite of Sheep Creek (Upper Cretaceous)
    Kgl	Granodiorite of Lockwood Mountain (Upper Cretaceous)
    Pag	Frazier Mountain augen gneiss (Lower Proterozoic)
    Pbg	Biotite gneiss  (Lower Proterozoic)
    Pqfg	Quartzofeldspathic gneiss (Lower Proterozoic)
    DEFINITION OF LINECODES IN THE COVERAGES (LINECODES AND DESC IN THE .CON AND .STR
    FEATURES IN THE DATABASE-------------------------
    LINECODE |   DESC
        1    | contact
        2    | contact, approximate (dashed)
        3    | contact, concealed (dotted)
       41    | water body
       81    | map boundary (lines of latitude or longitude)
       88    | limit of overturned strata
       98    | cross-section line
      102    | fault, unknown offset, approximate (dashed)
      103    | fault, unknown offset, concealed (dotted)
      111    | normal fault
      112    | normal fault, approximate (dashed)
      113    | normal fault, concealed (dotted)
      161    | reverse fault
      162    | reverse fault, approximate (dashed)
      163    | reverse fault, concealed (dotted)
      173    | thrust fault, concealed (dotted)
      403    | horizontal anticline, concealed
      404    | plunging anticline, approximate
      406    | plunging anticline, concealed
      412    | double plunging anticline (out), concealed
      413    | horizontal syncline
      415    | horizontal syncline, concealed
      416    | plunging syncline
      417    | plunging syncline, approximate
      418    | plunging syncline, concealed
      442    | overturned syncline, concealed
    
    Entity_and_Attribute_Detail_Citation:
    For description of map units, refer to map text (in file ofr-99-0130-p.pdf)

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Karl S. Kellogg
  2. Who also contributed to the data set?
    Compilation of map by Karl Kellogg; Radiometric data by Wayne Premo.
  3. To whom should users address questions about the data?

Why was the data set created?

To update and reinterpret earlier geologic mapping, and to achieve a uniform regional geologic database.

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: 1999 (process 1 of 10)
    Polygons, lines, and points representing geologic features and data points were digitized from scale-stable compilation materials using the GSMCAD public domain program (USGS Open-File Report 96-007).
    Date: 2000 (process 2 of 10)
    The map data were exported to ARC/INFO using the GSMCAD export function to create ARC generate ASCII files. The ASCII files were then imported into ArcInfo using the GENERATE routine, and polygon topology built.
    Date: 2000 (process 3 of 10)
    Text map unit descriptors were added to the .AAT and .PAT database files for each coverage.
    Date: 2000 (process 4 of 10)
    Draft check plots of the geologic map and explanation were created and submitted for peer review. Geologists reviewed the plots for conformity with U.S. Geological Survey editorial standards and stratigraphic nomenclature. Revisions were made to the geospatial database as needed.
    Date: 2000 (process 5 of 10)
    Coverages were edited and revised in ArcInfo 8.0.2 to reflect editorial changes and to further attribute polygons with descriptions and all features with source information.
    Date: 2000 (process 6 of 10)
    Final revisions to the digital database were made and a map layout (browse graphic) prepared in Adobe Illustrator and saved in PDF format.
    Date: 2001 (process 7 of 10)
    The geospatial database files and metadata were quality checked for completeness and consistency.
    Date: 2001 (process 8 of 10)
    The digital database was quality checked by the data manager, USGS Central Region Earth Surface Processes team.
    Date: 2001 (process 9 of 10)
    Final preparation of the geospatial database for distribution, and preparation of map-on-demand files and metadata.
    Date: 12-Feb-2001 (process 10 of 10)
    Creation of original metadata record Person who carried out this activity:
    Karl S. Kellogg
    U.S. Geological Survey
    U.S. Geological Survey
    Lakewood, CO

    303-236-1305 (voice)
  3. What similar or related data should the user be aware of?

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

  1. How well have the observations been checked?
    Data were entered and checked by the geologist that made the observations. The attributes of this geospatial data set consist of text identifiers and numeric codes that indicate the identity of the geologic unit or type of geologic feature, and determine how each feature is colored or symbolized. To check attribute accuracy, a color check plot was visually compared to the geologist's original compilation. Discrepancies between the digital geospatial dataset and the original analog compilation were corrected as needed. Machine-created listings of unique attribute values were used to identify spelling errors or other inconsistencies, and corrections were made as needed.
  2. How accurate are the geographic locations?
    Lines were primarily mapped by ground investigation and photointerpretation of 1:24,000-scale color aerial photographs. These lines were digitized from the topographic field sheets and from annotated aerial photographs. Most digitized positions on the map are estimated to have about 20 m horizontal accuracy. Additional point observations were added using positions determined by a Rockwell PLGR-96 GPS unit with horizontal accuracy of about 10 meters. There is no elevation data in the database.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Data are complete: no features were eliminated or generalized. Unit properties are described in the text explanation.
  5. How consistent are the relationships among the observations, including topology?
    Map elements were visually checked for overshoots, undershoots, duplicate features, polygon attributes, and other errors. Automated (ARC/INFO) routines were also used to check the databases for polygon label errors, line or point attribution errors, sliver polygons, dangling arcs, intersection errors, and projection information. The map was reviewed by one other geologist for consistency with basic geologic principles and general conformity to USGS mapping standards.

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:
none. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    Central Publications Group
    Lakewood, CO

    303-236-5486 (voice)
    tpinto@usgs.gov
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    Although this digital spatial data has been subjected to rigorous review and is substantially complete, it is released on the condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. This map is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code.
  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/99-130/metadata.faq.html>
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