Identification_Information:
  Citation:
    Citation_Information:
      Originator: Keith A. Howard
      Originator: Barbara E. John
      Originator: Jane E. Nielson
      Originator: Julia M. G. Miller
      Originator: Joseph L. Wooden
      Publication_Date: 2013
      Title: Geologic Map of the Topock 7.5-minute Quadrangle, Arizona and California
      Edition: Version 1.0
      Series_Information:
        Series_Name: Scientific Investigations Map
        Issue_Identification: 3236
      Publication_Information:
        Publication_Place: Reston, Virginia
        Publisher: U.S. Geological Survey
      Other_Citation_Details: Replaces U.S. Geological Survey Open-File Report 98-534 and part of U.S. Geological Survey Open-File Report 87-666
      Online_Linkage: http://pubs.usgs.gov/sim/3236
  Description:
    Abstract:
      This digital map database was compiled from new mapping and mapping contained in U.S. Geological Survey Open-File Reports 87-666 and 98-534 and the Geological Society of America Bulletin. The geodatabase contains data used to produce the Geologic Map of the Topock 7.5' Quadrangle, Arizona and California.

      The Topock quadrangle exposes part of the Colorado River extensional corridor and deposits that record Colorado River history. The quadrangle straddles the Colorado River in Mohave County, Arizona and San Bernardino County, California.  The map and accompanying report depict metamorphic and intrusive rocks of Proterozoic to Cretaceous age, Miocene rocks deposited and emplaced during an episode of tectonic extension, and stratigraphy of younger Miocene to historical Colorado River and locally derived sedimentary deposits.  

      This metadata report provides an overview of the data in this geodatabase.  Refer to metadata within each feature class (with the exception of annotation feature classes) for detailed Spatial Data Organization, Data Quality, and Entity Attribute information.
    Purpose: Geologic mapping and investigations for this report were performed to improve understanding of geologic structure, history, and resources in a well exposed, structurally complex part of the Basin and Range province, and to elucidate the stratigraphic architecture and landscape evolution of the Colorado River and its valley. The studies were done in cooperation with the Bureau of Land Management, Bureau of Mines, University of California, Fish and Wildlife Service, National Science Foundation, and Bureau of Reclamation. The pamphlet and accompanying map are intended to be useful to the scientific community and to support resource management activities.
    Supplemental_Information:
      The structure of this geodatabase and its associated feature classes, as well as the feature class naming conventions, loosely follows The National Park Service Geologic Resources Evaluation Geology-GIS Geodatabase Data Model (V. 2.1), which can be found at: http://science.nature.nps.gov/im/inventory/geology/GeologyGISDataModel.htm

      This geodatabase includes the following:
      Feature classes:
            geologic attitude and observation points (topock_atd)
            igneous dikes (topock_dike)
            fold axes (topock_fold)
            fluvial scarps (topock_scarp)
            cross section lines (topock_sec)
            geologic contacts and faults (topockglg_arc)
            geologic unit polygons (topockglg_poly)
            geologic unit points (topockglg_pt)

      Annotation feature classes:
            geologic attitude and observation point annotation (topock_atdAnno)
            geologic unit annotation (topockglg_ptAnno)

      Relationship classes:
            topock_atdAnno - links topock_atd to topock_atdAnno
            topockglg_ptAnno - links topockglg_pt to topockglg_ptAnno
  Time_Period_of_Content:
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date: 1980
        Ending_Date: 2009
    Currentness_Reference: ground condition
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: None planned
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: none
      Theme_Keyword: geology
      Theme_Keyword: geologic map
    Place:
      Place_Keyword_Thesaurus: none
      Place_Keyword: United States of America
      Place_Keyword: California
      Place_Keyword: Arizona
      Place_Keyword: Mohave County
      Place_Keyword: San Bernardino County
  Access_Constraints: none
  Use_Constraints: Not for use at scales greater than 1:24,000.  Any derivative products utilizing these datasets shall clearly indicate their source.  If users modify the data in any way they are obligated to describe the types of modifications they have performed.  User specifically agrees not to misrepresent these datasets, nor to imply that changes they made were approved by the U.S. Geological Survey.
  Point_of_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Keith Howard
        Contact_Organization: U.S. Geological Survey
      Contact_Position: Geologist, emeritus
      Contact_Address:
        Address_Type: mailing and physical address
        Address: 345 Middlefield Rd.; MS 973
        City: Menlo Park
        State_or_Province: California
        Postal_Code: 94025
        Country: USA
      Contact_Voice_Telephone: 650-329-4943
      Contact_Facsimile_Telephone: 650-329-5133
      Contact_Electronic_Mail_Address: khoward@usgs.gov
  Data_Set_Credit: This digital database was prepared by Sue Priest, with prior work from Sebastian Roberts, Zachary Anderson, and Tracey Felger.  Technical review was provided by L. Sue Beard and P. Kyle House, U.S. Geological Survey and James E. Faulds, Nevada Bureau of Mines and Geology.  Digital review was provided by Kyle House of the U.S. Geological Survey.
  Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report: Geologic features in this geodatabase were symbolized based on attributes and plotted at 1:24,000-scale, then visually reviewed for accuracy by the authors.
  Logical_Consistency_Report: This geodatabase has been reviewed and is considered to be error-free.  All features have attributes.  Each line segment has a length and directionality that is appropriate for the geologic feature it depicts.  No sliver polygons are present.
  Completeness_Report: This geodatabase is considered complete.  All geologic features depicted on the source maps were digitized and attributed.
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report:
        Most of the geologic features in this database are considered to be accurately located and within +/- 5 meters of their actual location on the 1:24,000-scale topographic base maps.  Accuracy diminishes in areas where topography is either flat or very steep.  The 1:24,000 topographic maps and corresponding Digital Raster Graphics (DRGs) used as the primary mapping base for this project were assumed to meet the National Map Accuracy Standard of +/- 12 meters.  The scanned source maps, which were georeferenced to the DRG's, all had registration errors of less than +/- 12 meters, and most had errors of less than +/- 5 meters.

        Note:  Refer to metadata for each feature class for detailed information about the positional accuracy of features.
  Lineage:
    Process_Step:
      Process_Description: Mapping was accomplished using a combination of field investigations and interpretation of aerial photographs and satellite images.  Geologic data, compiled by hand on a 1:24,000-scale mylar topographic base map, was scanned and saved in TIF format.  The TIF files were georeferenced in ArcMap to the corresponding 1:24,000-scale DRGs, using a 1st-order polynomial transformation.  The scanned compilation maps and DRGs were used as a guide from which geologic data were digitized.  The ArcCatalog process "Create new polygon feature class from lines and points" was used to create geologic unit polygons from digitized contacts (topockglg_arc) and unit labels (topockglg_pt).  Each feature class was symbolized based on attributes and edited as needed to achieve an error-free database.
Spatial_Data_Organization_Information:
  Point_and_Vector_Object_Information:
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Geodetic_Model:
  Vertical_Coordinate_System_Definition:
    Altitude_System_Definition:
Entity_and_Attribute_Information:
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: geology
      Entity_Type_Definition: Feature dataset containing geologic data feature classes, including geologic attitude and observation points (topock_atd), volcanic dikes (topock_dike), fold axes (topock_fld), fluvial scarps (topock_scarp), contacts and faults (topockglg_arc), geologic unit polygons (topockglg_poly), geologic unit points (topockglg_pt), and cross section lines (topock_sec).  Two feature classes, topock_atd and topockglg_pt, have associated feature-linked annotation and relationship classes (topock_atdAnno and topockglg_ptAnno).
      Entity_Type_Definition_Source: Author
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: topock_lmu
      Entity_Type_Definition: List of geologic map units and their associated plain text and FGDCGeoAge font map label.
      Entity_Type_Definition_Source: Author
Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U.S. Geological Survey Information Services
      Contact_Address:
        Address_Type: mailing address
        Address: Box 25286 Denver Federal Center
        City: Denver
        State_or_Province: Colorado
        Postal_Code: 80225
        Country: USA
      Contact_Voice_Telephone: 1-888-ASK-USGS
      Contact_Electronic_Mail_Address: ask@usgs.gov
  Resource_Description: Downloadable Data
  Distribution_Liability:
    The U.S. Geological Survey (USGS) provides these geospatial data "as is."  The USGS makes no guarantee or warranty concerning the accuracy of information contained in the geospatial 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.
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: ArcGIS Personal Geodatabase
        Format_Version_Number: 9.3
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: http://pubs.usgs.gov/sim/3236
    Fees: None
Metadata_Reference_Information:
  Metadata_Date: 20090506
  Metadata_Review_Date: 20110809
  Metadata_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Susan S. Priest
        Contact_Organization: U.S. Geological Survey
      Contact_Position: Geologist
      Contact_Address:
        Address_Type: mailing and physical address
        Address: 2255 N. Gemini Dr.
        City: Flagstaff
        State_or_Province: Arizona
        Postal_Code: 86001
        Country: USA
      Contact_Voice_Telephone: 928-556-7148
      Contact_Facsimile_Telephone: 928-556-7169
      Contact_Electronic_Mail_Address: spriest@usgs.gov
  Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998
  Metadata_Time_Convention: local time
  Metadata_Access_Constraints: None
  Metadata_Use_Constraints: None
  Metadata_Extensions:
    Online_Linkage: http://www.esri.com/metadata/esriprof80.html
    Profile_Name: ESRI Metadata Profile