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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. N. Grossman</dc:contributor>
  <dc:contributor>C.T. Olinger</dc:contributor>
  <dc:contributor>D.H. Garrison</dc:contributor>
  <dc:creator>T. D. Swindle</dc:creator>
  <dc:date>1991</dc:date>
  <dc:description>&lt;div id="preview-section-abstract"&gt;&lt;div id="abstracts" class="Abstracts u-font-serif text-s"&gt;&lt;div id="aep-abstract-id5" class="abstract author"&gt;&lt;div id="aep-abstract-sec-id6"&gt;&lt;p&gt;We have performed INAA, petrographie, and noble gas analyses on seventeen chondrules from the Semarkona meteorite (LL3.0) primarily to study the relationship of the I-Xe system to other measured properties. We observe a range of ≥10 Ma in apparent I-Xe ages. The three latest apparent ages fall in a cluster, suggesting the possibility of a common event. The initial&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;129&lt;/sup&gt;I/&lt;sup&gt;127&lt;/sup&gt;I ratio (&lt;i&gt;R&lt;/i&gt;&lt;sub&gt;0&lt;/sub&gt;) is apparently related to chondrule type and/or mineralogy, with nonporphyritic and pyroxene-rich chondrules showing evidence for lower&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;R&lt;/i&gt;&lt;sub&gt;0&lt;/sub&gt;'S (later apparent I-Xe ages) than porphyritic and olivine-rich chondrules. In addition, chondrules with sulfides on or near the surface have lower&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;R&lt;/i&gt;&lt;sub&gt;0&lt;/sub&gt;S than other chondrules. The&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;129&lt;/sup&gt;Xe/&lt;sup&gt;132&lt;/sup&gt;Xe ratio in the trapped Xe component anticorrelates with&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;R&lt;/i&gt;&lt;sub&gt;0&lt;/sub&gt;, consistent with evolution of a chronometer in a closed system or in multiple similar systems. On the basis of these correlations, we conclude that the variations in&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;R&lt;/i&gt;&lt;sub&gt;0&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;represent variations in ages, and that later event(s), possibly aqueous alteration, preferentially affected chondrules with nonporphyritic textures and/or sulfide-rich exteriors about 10 Ma after the formation of the chondrules.&lt;/p&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;div id="preview-section-introduction"&gt;&lt;br&gt;&lt;/div&gt;&lt;div id="preview-section-snippets"&gt;&lt;br&gt;&lt;/div&gt;&lt;div id="preview-section-references"&gt;&lt;br&gt;&lt;/div&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/0016-7037(91)90070-L</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Iodine-xenon, chemical, and petrographie studies of Semarkona chondrules: Evidence for the timing of aqueous alteration</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>