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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:creator>A. H. Koschmann</dc:creator>
  <dc:date>1960</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;A&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Precambrian&lt;/span&gt;&lt;span&gt;&amp;nbsp;complex of granulite, gneiss, and migmatite, intruded by numerous plutons of granitic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;&amp;nbsp;correlated with the Silver Plume granite, is exposed&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;a long narrow belt along the crest and upper slopes of the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Tenmile&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Range&lt;/span&gt;&lt;span&gt;,&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Colorado&lt;/span&gt;&lt;span&gt;. The metamorphic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;&amp;nbsp;are predominantly felsic; bands, lenses, and irregular bodies of mafic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;&amp;nbsp;rich&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;biotite, hornblende, and locally&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;sillimanite and garnet, are interlayered with the felsic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;. The major lithologic variations&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the metamorphic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rock&lt;/span&gt;&lt;span&gt;&amp;nbsp;complex are believed to be due chiefly to variations&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the original sedimentary&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;, which probably were interbedded sandstone, shale, and limestone. The metamorphic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;&amp;nbsp;and the Silver Plume granite reveal the age relations of quartz and the feldspars, and these relations afford considerable information on the origin and progressive transformation of the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;. Quartz is the earliest&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;mineral&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the metamorphic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;&amp;nbsp;and is probably a relict&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;mineral&lt;/span&gt;&lt;span&gt;&amp;nbsp;of a sandstone. It has been partially replaced by feldspar. It occurs chiefly&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;irregular clusters, some of which show sutured grains, enclosed&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;a ramifying network of feldspar. Irregular small apophyses, barbs, and prongs of feldspar penetrate the quartz clusters along grain boundaries and healed fractures&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the quartz.&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;In&lt;/span&gt;&lt;span&gt;&amp;nbsp;some of the least feldspathized quartzose metamorphic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;&amp;nbsp;the feldspar is clearly interstitial to the quartz. Quartz also occurs&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;feldspar as small spherical inclusions. The relations of the quartz to the feldspars show clearly that a quartzose host&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rock&lt;/span&gt;&lt;span&gt;&amp;nbsp;was replaced by feldspar along quartz grain boundaries, pre-existing healed fractures, and margins of shadowy areas&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;strained quartz grains. The textural relations of the other principal minerals&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the metamorphic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;&amp;nbsp;show that plagioclase formed earlier than the microcline and that the micas were the last of the principal minerals to form. Identical paragenetic relations are found&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the Silver Plume granite, and the writer concludes that the Silver Plume granite was derived by partial fusion of quartzose metamorphic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;rocks&lt;/span&gt;&lt;span&gt;.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1130/0016-7606(1960)71[1357:MPOPRI]2.0.CO;2</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Geological Society of America</dc:publisher>
  <dc:title>Mineral paragenesis of precambrian rocks in the Tenmile Range, Colorado</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>