<?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>Harold Masursky</dc:contributor>
  <dc:contributor>A. L. Dial Jr.</dc:contributor>
  <dc:creator>M. G. Chapman</dc:creator>
  <dc:date>1991</dc:date>
  <dc:description>&lt;p&gt;&lt;span class="TextRun SCXW149066695 BCX8" lang="EN-US" xml:lang="EN-US" data-contrast="auto"&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt;This &lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt;map is one in a series of 1:500,000-scale geologic maps initiated by the National &lt;/span&gt;&lt;span class="ContextualSpellingAndGrammarError SCXW149066695 BCX8"&gt;Aeronautic&lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt; and Space Administration to investigate areas of &lt;/span&gt;&lt;span class="AdvancedProofingIssue SCXW149066695 BCX8"&gt;particular scientific&lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt; interest on &lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt;Mars.&lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt; The west Mangala Valles area merits detailed geologic study because it contains several small channels whose ages can be determined&lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt; relative to geologic units that range in age &lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt;from early (Noachian) to late (Amazonian) periods of &lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt;Martian history. Because the small channels are of three ages and channels of each age are of a geomorphic type &lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt;unique&lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt; to that age, their study increases our understanding of the continuity of &lt;/span&gt;&lt;span class="NormalTextRun SCXW149066695 BCX8"&gt;fluvial process on the evolutionary history of Mars. For these reasons, part of the area is a proposed-site for a sample-return mission to Mars.&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.3133/i2087</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>U.S. Geological Survey</dc:publisher>
  <dc:title>Geologic map of science study area 1B, west Mangala Valles region of Mars</dc:title>
  <dc:type>reports</dc:type>
</oai_dc:dc>