<?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:contributor>James G. Bockheim</dc:contributor>
  <dc:contributor>C. Kendall</dc:contributor>
  <dc:contributor>M. Thiemens</dc:contributor>
  <dc:creator>G. Michalski</dc:creator>
  <dc:date>2005</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Nitrates minerals from the Dry Valleys of Antarctica have been analyzed for their oxygen and nitrogen isotopic compositions. The &lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N was depleted with δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N values ranging from −9.5 to −26.2‰, whereas the &lt;/span&gt;&lt;sup&gt;17&lt;/sup&gt;&lt;span&gt;O and &lt;/span&gt;&lt;sup&gt;18&lt;/sup&gt;&lt;span&gt;O isotopes were highly enriched (with excess &lt;/span&gt;&lt;sup&gt;17&lt;/sup&gt;&lt;span&gt;O) with δ&lt;/span&gt;&lt;sup&gt;18&lt;/sup&gt;&lt;span&gt;O values spanning 62–76‰ and Δ&lt;/span&gt;&lt;sup&gt;17&lt;/sup&gt;&lt;span&gt;O values from 28.9 to 32.7‰. These are the largest &lt;/span&gt;&lt;sup&gt;17&lt;/sup&gt;&lt;span&gt;O enrichments observed in any known mineral. The oxygen isotopes indicate that nitrate is from a combination of tropospheric transport of photochemically produced HNO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt; and HNO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt; formed in the stratosphere.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1029/2004GL022121</dc:identifier>
  <dc:language>en</dc:language>
  <dc:title>Isotopic composition of Antarctic Dry Valley nitrate: Implications for NOy sources and cycling in Antarctica</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>