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<article article-type="research-article">
<front>
<journal-meta>
<journal-id journal-id-type="archive">gsminmag</journal-id>
<journal-title>Mineralogical Magazine</journal-title>
<abbrev-journal-title abbrev-type="full">Mineralogical Magazine</abbrev-journal-title>
<issn pub-type="ppub">0026-461X</issn>
<publisher>
<publisher-name>Mineralogical Society</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.1180/minmag.1982.045.337.20</article-id>
<title-group>
<article-title>Porphyritic-Nodular, Nodular, and Orbicular Chrome Ores from the Sakhakot-Qila Complex Pakistan, and Their Chemical Variations</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname>Ahmed</surname>
<given-names>Zulfiqar</given-names>
</name>
<xref ref-type="author-notes" rid="FN1">*</xref>
<aff>Department of Geology, University of London, King's College, London WC2R 2LS</aff></contrib></contrib-group>
<author-notes>
<fn fn-type="present-address" id="FN1"><label>*</label><p>Permanent address: Institute of Geology, University of the Punjab, New Campus, Lahore, Pakistan.</p></fn></author-notes>
<pub-date pub-type="ppub">
<year>1982</year>
</pub-date>
<volume>45</volume>
<issue>337</issue>
<fpage>167</fpage>
<lpage>178</lpage>
<copyright-statement>Copyright &#x00A9; 1982, The Mineralogical Society</copyright-statement>
<copyright-year>1982</copyright-year>
<abstract>
<title>Abstract</title>
<p>A new kind of chromitite texture&#x2014;a porphyritic nodular texture, found in an alpine-type complex in Pakistan, is described. The chromite from phenocrystic nodules and that from their disseminated chromitite groundmass show comparable trivalent elements and postcumulus to subsolidus Mg&#x2212;Fe<sup>2+</sup> variations, which are also recorded from &#x2018;normal&#x2019; nodular ore samples. The nodular ores differ from all other textural types of chromitite from this complex in an unusual, though slight, increase in Cr/(Cr+Al) with Mg/(Mg+Fe<sup>2+</sup>) between stratigraphically different desposits, which is caused by magmatic differences. The implications of major element variations in chromites and olivines of nodular chromirites are discussed and a cumulus origin is supported. Temperatures of final chromite-olivine equilibration ranged from 750 to 900 &#x00B0;C the individual nominal values being higher for chromitite with coarser chromite crystals and, or, higher chromite:silicate ratio.</p></abstract>
</article-meta>
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</article>
