<metadata>
  <idinfo>
    <citation>
      <citeinfo>
        <origin>Steve Ludington, USGS, Scientist Emeriti</origin>
        <title>EASIA_pCu_Tracts</title>
        <geoform>vector digital data</geoform>
      </citeinfo>
    </citation>
    <descript>
      <abstract>Mineral resource assessments provide a synthesis of available information about distribution of mineral deposits in the Earth's crust. A probabilistic mineral resource assessment of undiscovered resources in Mesozoic porphyry copper deposits in East Asia was done as part of a global mineral resource assessment (GMRAP). The purpose of the assessment was to (1) compile a database of known porphyry copper deposits and significant prospects, (2) delineate permissive areas (tracts) for undiscovered porphyry copper deposits at a scale of 1:1,000,000, (3) estimate numbers of undiscovered deposits within those permissive tracts, and (4) provide probabilistic estimates of amounts of copper (Cu), molybdenum (Mo), gold (Au), and silver (Ag) that could be contained in those undiscovered deposits. The study was conducted in part in cooperation with the China Geological Survey (CGS) between 2002 and 2010 using a three-part form of mineral resource assessment based on mineral deposit models (Singer, 1993). Delineation of permissive tracts primarily was based on distributions of mapped post-subduction igneous rocks. Using a GIS, map units were selected from digital geologic maps based on lithology and age to delineate 3 permissive tracts. Distributions of known deposits, prospects, aeromagnetic data, and exploration history were considered in conjunction with descriptive deposit models and grade and tonnage models to guide estimates. This shapefile contains the permissive tracts. Attributes include estimates of numbers of undiscovered porphyry copper deposits and estimates of mean expected resources associated with each tract.</abstract>
      <purpose>To delineate where undiscovered porphyry copper deposits may occur within the upper kilometer of the Earths crust. Created for Scientific Investigations Series Report 2010-5090-[x], which is part of the USGS assessment of undiscovered copper resources of the world.</purpose>
    </descript>
    <status>
      <update>None planned</update>
    </status>
    <spdom>
      <bounding>
        <westbc>86.184315</westbc>
        <eastbc>141.902666</eastbc>
        <northbc>62.709236</northbc>
        <southbc>15.847924</southbc>
      </bounding>
    </spdom>
    <keywords>
      <theme>
        <themekt>None</themekt>
        <themekey>porphyry copper</themekey>
        <themekey>permissive tract</themekey>
        <themekey>deposit</themekey>
        <themekey>prospect</themekey>
        <themekey>global mineral resource assessment</themekey>
      </theme>
    </keywords>
    <accconst>None</accconst>
    <useconst>This spatial database is not meant to be used or displayed at any scale larger than 1:1,000,000 (for example, 1:500,000).</useconst>
    <ptcontac>
      <cntinfo>
        <cntorgp>
          <cntorg>USGS</cntorg>
          <cntper>Steve Ludington</cntper>
        </cntorgp>
        <cntpos>Scientist Emeriti</cntpos>
        <cntaddr>
          <addrtype>mailing and physical</addrtype>
          <address>345 Middlefield Rd.</address>
          <address>Room 2214</address>
          <city>Menlo Park</city>
          <state>California</state>
          <postal>94025-3561</postal>
          <country>UNITED STATES</country>
        </cntaddr>
        <cntvoice>650-329-5371</cntvoice>
        <cntfax>650-329-5491</cntfax>
        <cntemail>slud@usgs.gov</cntemail>
      </cntinfo>
    </ptcontac>
    <datacred>Steve Ludington (principal author) delineated tracts and participated in estimation; Jane M. Hammarstrom and Gilpin R. Robinson Jr. participated in estimation of all 3 tracts. Dmitry Alexiev, Arthur A. Bookstrom, Thomas P. Frost, Thomas Light, Mark Mihalasky and Andre Panteleyev participated in the estimation tract 142pCu8509.</datacred>
    <native>Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcGIS 10.0.4.4000</native>
  </idinfo>
  <spdoinfo>
    <direct>Vector</direct>
    <ptvctinf>
      <sdtsterm>
        <sdtstype>GT-polygon composed of chains</sdtstype>
        <ptvctcnt>3</ptvctcnt>
      </sdtsterm>
    </ptvctinf>
  </spdoinfo>
  <spref>
    <horizsys>
      <planar>
        <mapproj>
          <mapprojn>Lambert Conformal Conic</mapprojn>
          <lambertc>
            <stdparll>15.0</stdparll>
            <stdparll>65.0</stdparll>
            <longcm>95.0</longcm>
            <latprjo>30.0</latprjo>
            <feast>0.0</feast>
            <fnorth>0.0</fnorth>
          </lambertc>
        </mapproj>
        <planci>
          <plance>coordinate pair</plance>
          <coordrep>
            <absres>0.0001</absres>
            <ordres>0.0001</ordres>
          </coordrep>
          <plandu />
        </planci>
      </planar>
      <geodetic>
        <horizdn>D WGS 1984</horizdn>
        <ellips>WGS 1984</ellips>
        <semiaxis>6378137.0</semiaxis>
        <denflat>298.257223563</denflat>
      </geodetic>
    </horizsys>
  </spref>
  <eainfo>
    <detailed>
      <enttyp>
        <enttypl>EASIA_pCu_Tracts</enttypl>
        <enttypd>Permissive tracts for porphyry copper deposits,  China and Vietnam</enttypd>
        <enttypds>GMRAP</enttypds>
      </enttyp>
      <attr>
        <attrlabl>OBJECTID</attrlabl>
        <attrdef>Internal feature number.</attrdef>
        <attrdefs>ESRI</attrdefs>
        <attrdomv>
          <udom>Sequential unique whole numbers that are automatically generated.</udom>
        </attrdomv>
      </attr>
      <attr>
        <attrlabl>Shape</attrlabl>
        <attrdef>Feature geometry.</attrdef>
        <attrdefs>ESRI</attrdefs>
        <attrdomv>
          <udom>Coordinates defining the features.</udom>
        </attrdomv>
      </attr>
      <attr>
        <attrlabl>Tract_ID</attrlabl>
        <attrdef>User-defined, unique identifier assigned to permissive tract.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Coded_ID</attrlabl>
        <attrdef>Coded, unique identifier assigned to permissive tract.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Tract_name</attrlabl>
        <attrdef>Informal name of permissive tract.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Unregcode</attrlabl>
        <attrdef>Three digit UN code for the region that underlies most of the permissive tract.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Country</attrlabl>
        <attrdef>Country(ies) in which the permissive tract is located.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Commodity</attrlabl>
        <attrdef>Primary commodity being assessed.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Dep_type</attrlabl>
        <attrdef>Name of the deposit type assessed.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>GT_model</attrlabl>
        <attrdef>Grade-tonnage model used for the undiscovered deposit estimate.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Geology</attrlabl>
        <attrdef>Geologic feature assessed.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Age</attrlabl>
        <attrdef>Age of the assessed geologic feature.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Asmt_date</attrlabl>
        <attrdef>Year assessment was conducted.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Asmt_depth</attrlabl>
        <attrdef>Maximum depth beneath the Earth's surface used for the assessment, in kilometers.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Est_levels</attrlabl>
        <attrdef>The set of percentile (probability) levels at which undiscovered deposit estimates were made.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>N90</attrlabl>
        <attrdef>Estimated number of deposits associated with the 90th percentile (90 percent chance of at least the indicated number of deposits).</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>N50</attrlabl>
        <attrdef>Estimated number of deposits associated with the 50th percentile (50 percent chance of at least the indicated number of deposits).</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>N10</attrlabl>
        <attrdef>Estimated number of deposits associated with the 10th percentile (10 percent chance of at least the indicated number of deposits).</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>N05</attrlabl>
        <attrdef>Estimated number of deposits associated with the 5th percentile (5 percent chance of at least the indicated number of deposits).</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>N01</attrlabl>
        <attrdef>Estimated number of deposits associated with the 1st percentile (1 percent chance of at least the indicated number of deposits).</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>N_expected</attrlabl>
        <attrdef>Expected (mean) number of deposits. N_Expected = (0.233*N90) + (0.4*N50) + (0.225*N10) + (0.045*N05) + (0.03*N01)</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>s</attrlabl>
        <attrdef>Standard deviation. s = 0.121 - (0.237*N90) - (0.093*N50) + (0.183*N10) + (0.073*N05) + (0.123*N01)</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Cv_percent</attrlabl>
        <attrdef>Coefficient of variance, in percent. Cv = (s/N_Expected) * 100</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>N_known</attrlabl>
        <attrdef>Number of known deposits in the tract.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>N_total</attrlabl>
        <attrdef>Total number of deposits. N_total = N_Expected + N_Known</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Area_raw</attrlabl>
        <attrdef>area raw</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Area_km2</attrlabl>
        <attrdef>Area of permissive tract, in square kilometers.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>DepDensity</attrlabl>
        <attrdef>Deposit density (total number of deposits per square kilometer). DepDensity = N_total/Area_km2</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>DepDen10E5</attrlabl>
        <attrdef>Deposit density per 100,000 square kilometers. DepDen10E5 = DepDensity*100,000</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Estimators</attrlabl>
        <attrdef>Names of people on the estimation team.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Notes</attrlabl>
        <attrdef>Miscellaneous notes or comments.</attrdef>
        <attrdefs>GMRAP</attrdefs>
      </attr>
      <attr>
        <attrlabl>Shape_Length</attrlabl>
        <attrdef>Length of feature in internal units.</attrdef>
        <attrdefs>ESRI</attrdefs>
        <attrdomv>
          <udom>Positive real numbers that are automatically generated.</udom>
        </attrdomv>
      </attr>
      <attr>
        <attrlabl>Shape_Area</attrlabl>
        <attrdef>Area of feature in internal units squared.</attrdef>
        <attrdefs>ESRI</attrdefs>
        <attrdomv>
          <udom>Positive real numbers that are automatically generated.</udom>
        </attrdomv>
      </attr>
    </detailed>
  </eainfo>
  <distinfo>
    <distrib>
      <cntinfo>
        <cntorgp>
          <cntorg>U.S. Geological Survey Information Services</cntorg>
        </cntorgp>
        <cntaddr>
          <addrtype>mailing</addrtype>
          <address>P.O. Box 25286</address>
          <address>Denver Federal Center</address>
          <city>Denver</city>
          <state>Colorado</state>
          <postal>80225</postal>
          <country>UNITED STATES</country>
        </cntaddr>
        <cntvoice>(888) ASK-USGS</cntvoice>
        <cntemail>infoservices@usgs.gov</cntemail>
      </cntinfo>
    </distrib>
    <distliab>See access and use constraints information.</distliab>
    <stdorder>
      <digform>
        <digtinfo>
          <formname>feature class</formname>
          <transize>1.853</transize>
        </digtinfo>
        <digtopt />
      </digform>
    </stdorder>
  </distinfo>
  <metainfo>
    <metd>20121114</metd>
    <metc>
      <cntinfo>
        <cntorgp>
          <cntorg>USGS</cntorg>
          <cntper>Connie L Dicken</cntper>
        </cntorgp>
        <cntpos>Geologist/GIS Specialist</cntpos>
        <cntaddr>
          <addrtype>mailing and physical</addrtype>
          <address>12201 Sunrise Valley Dr.  MS954</address>
          <city>Reston</city>
          <state>Virginia</state>
          <postal>20192</postal>
          <country>UNITED STATES</country>
        </cntaddr>
        <cntvoice>703-648-6482</cntvoice>
        <cntfax>703-648-6252</cntfax>
        <cntemail>cdicken@usgs.gov</cntemail>
      </cntinfo>
    </metc>
    <metstdn>FGDC Content Standard for Digital Geospatial Metadata</metstdn>
    <metstdv>FGDC-STD-001-1998</metstdv>
    <mettc>local time</mettc>
  </metainfo>
</metadata>