<?xml version='1.0' encoding='utf-8'?>
<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:contributor>R.Q. Lewis</dc:contributor>
  <dc:creator>R. H. Campbell</dc:creator>
  <dc:date>1961</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;The&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Elk&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Ridge&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;area&lt;/span&gt;&lt;span&gt;&amp;nbsp;of southeastern&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Utah&lt;/span&gt;&lt;span&gt;&amp;nbsp;contains&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;uranium&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;deposits&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;two lower members of the Chinle formation of Late Triassic age. Each member is mineralized&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;different parts of the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;area&lt;/span&gt;&lt;span&gt;, and where both are present only the lower contains&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;. Across the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Elk&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Ridge&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;area&lt;/span&gt;&lt;span&gt;&amp;nbsp;from southwest to northeast, successively younger beds lap onto the unconformity that separates the Chinle from the underlying Moenkopi formation of Triassic(?), Early and Middle(?) Triassic age. Important&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;uranium&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;deposits&lt;/span&gt;&lt;span&gt;&amp;nbsp;have been found only&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;sandstone beds of the Chinle that are&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;contact with the Moenkopi. Sandstone of the Chinle formation lies on the Moenkopi (or is separated from it by gray mudstone of the Chinle no thicker than the depths of most of the known paleostream channel scours)&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;two separate parts of the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Elk&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Ridge&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;area&lt;/span&gt;&lt;span&gt;. These "favorable areas" contain all the mines and important prospects. The&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;deposits&lt;/span&gt;&lt;span&gt;&amp;nbsp;are flat-lying tabular to lenticular bodies&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;fluvial sandstone beds of the Chinle with fine-grained black&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;uranium&lt;/span&gt;&lt;span&gt;&amp;nbsp;minerals chiefly interstitial to sand grains and as replacement of carbonaceous material. Most of the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;-bearing sandstone beds are discontinuous lenses intertonguing with and overlain by relatively impermeable mudstone. Contact of the host sandstone with the underlying Moenkopi seems to be a prerequisite for&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;&amp;nbsp;as the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;&amp;nbsp;bodies are generally within a few feet of such contact areas and sandstone lenses separated from the Moenkopi by gray mudstone are generally not&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;&amp;nbsp;bearing. The consistent association of&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;deposits&lt;/span&gt;&lt;span&gt;&amp;nbsp;with the Chinle-Moenkopi contact suggests that mineralizing solutions were introduced into the host beds from their areas of contact with the Moenkopi formation. Impermeable barriers overlying&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;-bearing parts of the host sandstones were probably an important control on the deposition of&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;&amp;nbsp;minerals from solution. Hypofiltration of metallic constituents from ascending&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;&amp;nbsp;solutions may have been important. It is also possible that the overlying barriers formed traps for H2S gas or fluid hydrocarbons and thus localized a reducing chemical environment&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;which&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;ore&lt;/span&gt;&lt;span&gt;&amp;nbsp;minerals were later precipitated.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.2113/gsecongeo.56.1.111</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Society of Economic Geologists</dc:publisher>
  <dc:title>Distribution of uranium ore deposits in the elk ridge area, San Juan County, Utah</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>