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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>Wayne C. Shanks III</dc:contributor>
  <dc:creator>J.M. Peter</dc:creator>
  <dc:date>1992</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-id3" class="abstract author"&gt;&lt;div id="aep-abstract-sec-id4"&gt;&lt;p&gt;Sulfur, carbon, and oxygen isotope values were measured in sulfide, sulfate, and carbonate from hydrothermal chimney, spire, and mound samples in the southern trough of Guaymas Basin, Gulf of California, USA.&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;34&lt;/sup&gt;&lt;i&gt;S&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;values of sulfides range from −3.7 to 4.5%. and indicate that sulfur originated from several sources:&lt;/p&gt;&lt;ul class="list"&gt;&lt;li class="react-xocs-list-item"&gt;&lt;span class="list-label"&gt;1.&lt;/span&gt;&lt;p&gt;(1) dissolution of 0‰ sulfide contained within basaltic rocks,&lt;/p&gt;&lt;/li&gt;&lt;li class="react-xocs-list-item"&gt;&lt;span class="list-label"&gt;2.&lt;/span&gt;&lt;p&gt;(2) thermal reduction of seawater sulfate during sediment alteration reactions in feeder zones to give sulfide with positive&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;34&lt;/sup&gt;&lt;i&gt;S&lt;/i&gt;, and&lt;/p&gt;&lt;/li&gt;&lt;li class="react-xocs-list-item"&gt;&lt;span class="list-label"&gt;3.&lt;/span&gt;&lt;p&gt;(3) entrainment or leaching of isotopically light (negative-&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;34&lt;/sup&gt;&lt;i&gt;S&lt;/i&gt;) bacteriogenic sulfide from sediments underlying the deposits.&lt;/p&gt;&lt;/li&gt;&lt;/ul&gt;&lt;p&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;34&lt;/sup&gt;&lt;i&gt;S&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;of barite and anhydrite indicate sulfur derivation mainly from unfractionated seawater sulfate, although some samples show evidence of sulfate reduction and sulfide oxidation reactions during mixing within chimneys.&lt;/p&gt;&lt;p&gt;Oxygen isotope temperatures calculated for chimney calcites are in reasonable agreement with measured vent fluid temperatures and fluid inclusion trapping temperatures. Hydrothermal fluids that formed calcite-rich chimneys in the southern trough of Guaymas Basin were enriched in&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;18&lt;/sup&gt;O with respect to seawater by about 2.4‰ due to isotopic exchange with sedimentary and/or basaltic rocks. Carbon isotope values of calcite range from −9.6 to −14.0‰&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;34&lt;/sup&gt;&lt;i&gt;C&lt;/i&gt;&lt;sub&gt;&lt;i&gt;pDB&lt;/i&gt;&lt;/sub&gt;, indicating that carbon was derived in approximately equal quantities from the dissolution of marine carbonate minerals and the oxidation of organic matter during migration of hydrothermal fluid through the underlying sediment column. Statistically significant positive, linear correlations of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;34&lt;/sup&gt;&lt;i&gt;S&lt;/i&gt;,&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;34&lt;/sup&gt;&lt;i&gt;C&lt;/i&gt;, and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;18&lt;/sup&gt;&lt;i&gt;O&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;of sulfides and calcites with geographic location within the southern trough of Guaymas Basin are best explained by variations in water/rock (&lt;span class="math"&gt;&lt;span id="MathJax-Element-1-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;mtext&gt;w&lt;/mtext&gt;&lt;mtext&gt;r&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;wr&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;) ratios or sediment reactivity within subsurface alteration zones. Low&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="math"&gt;&lt;span id="MathJax-Element-2-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;mtext&gt;w&lt;/mtext&gt;&lt;mtext&gt;r&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;wr&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;ratios and the leaching of detrital carbonates and bacteriogenic sulfides at the southern vent sites result in relatively high&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;13&lt;/sup&gt;&lt;i&gt;C&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;and low&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;34&lt;/sup&gt;&lt;i&gt;S&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;in chimney carbonates and sulfides, respectively. In the north, where the depletion of alkalis in vent fluids indicates higher&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="math"&gt;&lt;span id="MathJax-Element-3-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;mtext&gt;w&lt;/mtext&gt;&lt;mtext&gt;r&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;wr&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;ratios, positive&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;34&lt;/sup&gt;&lt;i&gt;S&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;and more negative&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;δ&lt;/i&gt;&lt;sup&gt;13&lt;/sup&gt;&lt;i&gt;c&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;are due to increased contributions from organic matter oxidation and sulfate reduction reactions.&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(92)90327-F</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Sulfur, carbon, and oxygen isotope variations in submarine hydrothermal deposits of Guaymas Basin, Gulf of California, USA</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>