<?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>Norman Herz</dc:creator>
  <dc:date>1975</dc:date>
  <dc:description>&lt;p&gt;Many types of alkalic rocks are enriched in Ti0&lt;sub&gt;2&lt;/sub&gt; relative to the average for the crust. Silicate minerals in these rocks may have high Ti0&lt;sub&gt;2&lt;/sub&gt; contents, but the oxides ilmenite, rutile, brookite, and perovskite are also characteristic primary phases. These tend to be higher in niobium than are the same minerals from other rock suites.&lt;/p&gt;&lt;p&gt;At Tapira, Brazil, titanium minerals in a carbonatite complex comprise tens of millions of tons contained Ti0&lt;sub&gt;2. &lt;/sub&gt;Anatase (as "leucoxene") is present in laterite lying over parent rocks containing perovskite, ilmenite, and rutile. In other discovered localities of alkalic rocks, production of titanium minerals is at best economically marginal.&lt;br&gt;&lt;br&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.3133/ofr7535</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>U.S. Geological Survey</dc:publisher>
  <dc:title>Titanium deposits in alkalic igneous rocks</dc:title>
  <dc:type>reports</dc:type>
</oai_dc:dc>