<?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:creator>R. A. Gulbrandsen</dc:creator>
  <dc:date>1966</dc:date>
  <dc:description>&lt;p&gt;The chemical composition, both major and minor constituents, of 60 samples of phosphorite from the Phosphoria Formation was determined. Major constituents of the average phosphorite are, by weight per cent: SiO&lt;sub&gt;2&lt;/sub&gt;, 11·9; Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;, 1·7; Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;,1·1; MgO, 0·3; CaO, 44·0; Na&lt;sub&gt;2&lt;/sub&gt;O, 0·6; K&lt;sub&gt;2&lt;/sub&gt;O, 0·5; total H&lt;sub&gt;2&lt;/sub&gt;O, 2·2; H&lt;sub&gt;2&lt;/sub&gt;O&lt;sup&gt;−&lt;/sup&gt;, 0·6; TiO&lt;sub&gt;2&lt;/sub&gt;, 0·1; P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;, 30·5; CO&lt;sub&gt;2&lt;/sub&gt;, 2·2; SO&lt;sub&gt;3&lt;/sub&gt;, 1·8; F, 3·1; organic matter, 2·1; and oil, 0·2. Uranium averages 0·009 per cent.&lt;/p&gt;&lt;p&gt;The phosphate mineral is basically apatite, Ca&lt;sub&gt;5&lt;/sub&gt;(PO&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;F, with small but significant and variable substitutions—Na, Sr, U and Th for Ca, and CO&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;and SO&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;for PO&lt;sub&gt;4&lt;/sub&gt;.&lt;/p&gt;&lt;p&gt;Rare metals not associated with apatite are associated principally with the organic-matter component of the rocks. This group includes As, Ag, Cd, Cr, Cu, Mo, Ni, Sb, Se, V and Zn. Chromium is the most abundant, having a modal abundance of 0·1 per cent and a maximum concentration of 0·3 per cent.&lt;/p&gt;&lt;p&gt;The average phosphorite is composed of approximately 80 per cent apatite, 10 per cent quartz, 5 per cent muscovite-illite, 2 per cent organic matter, 1 per cent dolomite—calcite, 1 per cent iron oxide, and 1 per cent other components. It is texturally a medium-grained pellet phosphorite.&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/0016-7037(66)90131-1</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Chemical composition of phosphorites of the Phosphoria Formation</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>