<?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:creator>David H. Scott</dc:creator>
  <dc:date>1993</dc:date>
  <dc:description>&lt;p&gt;&lt;span class="TextRun SCXW42091357 BCX8" lang="EN-US" xml:lang="EN-US" data-contrast="auto"&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;Kasei Valles (fig. 1) make up the largest system of outflow channels on Mars and were a major contri&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;butor of water to &lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;Chryse&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; Planitia. The walls and floors of the Kasei channe&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;ls &lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;are terraced and grooved&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;, closely resembling the channeled scablands of easter&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;n&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; Washington &lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;State&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; that were formed by catastrophic floods probably last&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;ing no more than a few days (Baker and Milton, 1974; Baker and Kochel&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;, 1979). Evidence obtained from previous geologic mapping of parts of Kasei Valles (Chapman and Scott&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;, 1989) was n&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;ot conclusive as to whether water levels varied markedly during single flood and&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; erosional event or whether flooding&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; was episodic and marked by intermittent periods of scouring&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;. This problem&lt;/span&gt; &lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;–&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; whether one or several flood &lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;episodes occurred within individual water courses – has been &lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;a continuing issue in studies of Martian channel formation (Greeley and others, 1977)&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;.&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; Recent large-scale geologic mapping (Tanaka and Chapman, 1990) of Mangala Valles, another large outflow channel system in the &lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;Memnonia&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; region&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; of Mars, shows deposits of two p&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;eriods of flooding; the deposits are &lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;separated&lt;/span&gt; &lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;stratigraphically&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; by a lava flow. In areas around the &lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;C&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;h&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;ryse&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; basin, geologic studies (&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;for example, Greeley and others, 1977) indicate that more than one episode &lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;of channel formation occurred or, less likely, that flooding was of very long&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt; duration. Evidence disclosed by the present mapping indicates that flooding was episodic in Kasei Valles and probably occurred over protrac&lt;/span&gt;&lt;span class="NormalTextRun SCXW42091357 BCX8"&gt;ted time intervals throughout the Hesperian Periods and possibly in the Early to Middle Amazonian.&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.3133/i2208</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>U.S. Geological Survey</dc:publisher>
  <dc:title>Geologic map of the MTM 25057 and 25052 quadrangles, Kasei Valles region of Mars</dc:title>
  <dc:type>reports</dc:type>
</oai_dc:dc>