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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:contributor>J.R. Hein</dc:contributor>
  <dc:contributor>R.P. Rajani</dc:contributor>
  <dc:contributor>A.R. Chodankar</dc:contributor>
  <dc:creator>V.K. Banakar</dc:creator>
  <dc:date>2007</dc:date>
  <dc:description>&lt;div id="Abs1-section" class="c-article-section"&gt;&lt;div id="Abs1-content" class="c-article-section__content"&gt;&lt;p&gt;The major element relationships in ferromanganese (Fe-Mn) crusts from Afanasiy-Nikitin seamount (ANS), eastern equatorial Indian Ocean, appear to be atypical. High positive correlations (&lt;i&gt;r&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;= 0.99) between Mn/Co and Fe/Co ratios, and lack of correlation of those ratios with Co, Ce, and Ce/Co, indicate that the ANS Fe-Mn crusts are distinct from Pacific seamount Fe-Mn crusts, and reflect region-specific chemical characteristics. The platinum group elements (PGE: Ir, Ru, Rh, Pt, and Pd) and Au in ANS Fe-Mn crusts are derived from seawater and are mainly of terrestrial origin, with a minor cosmogenic component. The Ru/Rh (0.5–2) and Pt/Ru ratios (7–28) are closely comparable to ratios in continental basalts, whereas Pd/Ir ratios exhibit values (&amp;lt;2) similar to CI-chondrite (∼1). The chondrite-normalized PGE patterns are similar to those of igneous rocks, except that Pd is relatively depleted. The water depth of Fe-Mn crust formation appears to have a first-order control on both major element and PGE enrichments. These relationships are defined statistically by significant (&lt;i&gt;r&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&amp;gt; 0.75) correlations between water depth and Mn/Co, Fe/Co, Ce/Co, Co, and the PGEs. Fractionation of the PGE-Au from seawater during colloidal precipitation of the major-oxide phases is indicated by well-defined linear positive correlations (&lt;i&gt;r&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&amp;gt; 0.8) of Co and Ce with Ir, Ru, Rh, and Pt; Au/Co with Mn/Co; and by weak or no correlations of Pd with water depth, Co-normalized major-element ratios, and with the other PGE (&lt;i&gt;r&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&amp;lt; 0.5). The strong enrichment of Pt (up to 1 ppm) relative to the other PGE and its positive correlations with Ce and Co demonstrate a common link for the high concentrations of all three elements, which likely involves an oxidation reaction on the Mn-oxide and Fe-oxyhydroxide surfaces. The documented fractionation of PGE-Au and their positive association with redox sensitive Co and Ce may have applications in reconstructing past-ocean redox conditions and water masses.&lt;/p&gt;&lt;/div&gt;&lt;/div&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1007/s12040-007-0002-x</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Springer</dc:publisher>
  <dc:title>Platinum group elements and gold in ferromanganese crusts from Afanasiy-Nikitin seamount, equatorial Indian Ocean: Sources and fractionation</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>