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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.1984.048.347.04</article-id>
<title-group>
<article-title>Mineral Parageneses and Metamorphic Reactions in Metasedimentary Enclaves from the Archaean Gneiss Complex of North-West India</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname>Sharma</surname>
<given-names>Ram. S.</given-names>
</name>
<aff>Department of Geology, Banaras Hindu University, Varanasi, 221005, India</aff></contrib>
<contrib contrib-type="author">
<name>
<surname>Windley</surname>
<given-names>Brian F.</given-names>
</name>
<aff>Department of Geology, The University, Leicester LE1 7RH, UK</aff></contrib></contrib-group>
<pub-date pub-type="ppub">
<month>6</month>
<year>1984</year>
</pub-date>
<volume>48</volume>
<issue>347</issue>
<fpage>195</fpage>
<lpage>209</lpage>
<history>
<date date-type="received">
<day>7</day>
<month>2</month>
<year>1983</year>
</date>
<date date-type="rev-recd">
<day>21</day>
<month>6</month>
<year>1983</year>
</date></history>
<copyright-statement>Copyright &#x00A9; 1984, The Mineralogical Society</copyright-statement>
<copyright-year>1984</copyright-year>
<abstract>
<title>Abstract</title>
<p>Three metasedimentary enclaves up to a kilometre in length of contrasting compositions within the polymetamorphic Banded Gneissic Complex (&#x003E; 2580Ma) have been studied for their mineral parageneses and metamorphic conditions. The largest enclave, consisting of kyanite-chloritoid-muscovite schist with quartz or corundum, and kyanite-fuchsite-corundum &#x00B1; diaspore, was metamorphosed at most under lower amphibolite conditions, and is thus not isofacial with the surrounding schists and gneisses (of the &#x2018;basement&#x2019; complex) which reached sillimanite-grade metamorphism in the last orogenic cycle (Aravalli: 1650&#x2013;950Ma Orogeny) in Rajasthan.</p>
<p>The second enclave is a calc-silicate rock which occurs as a small lens. The presence of two generations of wollastonite which formed during different metamorphic events in the calcite-quartz-grossularite-anorthite-clinopyroxene assemblage indicates polymetamorphism.</p>
<p>The third enclave is a metabasic rock which records a complete polymetamorphic history in discontinuous zones in garnet coexisting with hornblende-chlorite-plagioclase-quartz&#x00B1;epidote. To explain the garnet zoning a model involving partial resorption of early garnet during the initial recrystallization stage of superimposed regional metamorphism is preferred to the alternative based on a single prograde metamorphism and retrogression.</p>
<p>The mineralogy of the calc-silicate and metabasic enclaves gives a recrystallization temperature of <italic>c.</italic> 700&#x00B0;C and a pressure in the range of 8&#x2013;3 kbar during the second metamorphism.</p></abstract>
</article-meta>
</front>
</article>
