<?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>D.J. Des Marais</dc:contributor>
  <dc:creator>R.S. Oremland</dc:creator>
  <dc:date>1983</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Distribution and isotopic composition (δ&lt;/span&gt;&lt;sup&gt;13&lt;/sup&gt;&lt;span&gt;C) of low molecular weight hydrocarbon gases were studied in Big Soda Lake (depth = 64 m), an alkaline, meromictic lake with permanently anoxic bottom waters. Methane increased with depth in the anoxic mixolimnion (depth = 20–35 m), reached uniform concentrations (55 μM/l) in the monimolimnion (35–64 m) and again increased with depth in monimolimnion bottom sediments (&amp;gt;400 μM/kg below 1 m sub-bottom depth). The&amp;nbsp;&lt;/span&gt;&lt;i&gt;μ&lt;/i&gt;&lt;sup&gt;13&lt;/sup&gt;&lt;i&gt;C&lt;/i&gt;&lt;span&gt;[&lt;/span&gt;&lt;i&gt;CH&lt;/i&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;] values in bottom sediment below 1 m sub-bottom depth (&amp;lt;−70 per mil) increased with vertical distance up the core (&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;[&lt;/span&gt;&lt;i&gt;CH&lt;/i&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;] = −55 per mil at sediment surface). Monimolimnion&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;[&lt;/span&gt;&lt;i&gt;CH&lt;/i&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;] values (−55 to −61 per mil) were greater than most&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;[&lt;/span&gt;&lt;i&gt;CH&lt;/i&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;] values found in the anoxic mixolimnion (92% of samples had&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;[&lt;/span&gt;&lt;i&gt;CH&lt;/i&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;] values between −20 and −48 per mil). No significant concentrations of ethylene or propylene were found in the lake. However ethane, propane, isobutane and&amp;nbsp;&lt;/span&gt;&lt;i&gt;n&lt;/i&gt;&lt;span&gt;-butane concentrations all increased with water column depth, with respective maximum concentrations of 260, 80, 23 and 22 nM/l encountered between 50–60 m depth. Concentrations of ethane, propane and butanes decreased with depth in the bottom sediments. Ratios of&amp;nbsp;&lt;/span&gt;&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;CH&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;[C&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;H&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;+ C&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;H&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;]&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;CH&lt;sub&gt;4&lt;/sub&gt;[C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;6&lt;/sub&gt;+ C&lt;sub&gt;3&lt;/sub&gt;H&lt;sub&gt;8&lt;/sub&gt;]&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;were high (250–620) in the anoxic mixolimnion, decreased to ~161 in the monimolimnion and increased with depth in the sediment to values as high as 1736. We concluded that methane has a biogenic origin in both the sediments and the anoxic water column and that C&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;-C&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;alkanes have biogenic origins in the monimolimnion water and shallow sediments. The changes observed in&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;[&lt;/span&gt;&lt;i&gt;CH&lt;/i&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;] and&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;CH&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;(C&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;H&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;+ C&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;H&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;)&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;CH&lt;sub&gt;4&lt;/sub&gt;(C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;6&lt;/sub&gt;+ C&lt;sub&gt;3&lt;/sub&gt;H&lt;sub&gt;8&lt;/sub&gt;)&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;with depth in the water column and sediments are probably caused by bacteria] processes. These might include anaerobic methane oxidation and different rates of methanogenesis and C&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;to C&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;alkane production by microorganisms.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/0016-7037(83)90035-2</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Distribution, abundance and carbon isotopic composition of gaseous hydrocarbons in Big Soda Lake, Nevada: An alkaline, meromictic lake</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>