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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>Niel Plummer</dc:contributor>
  <dc:creator>E. Busenberg</dc:creator>
  <dc:date>1985</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-id4" class="abstract author"&gt;&lt;div id="aep-abstract-sec-id5"&gt;&lt;p&gt;Significant amounts of SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, and OH&lt;sup&gt;−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;are incorporated in marine biogenic calcites. Biogenic high Mg-calcites average about 1 mole percent SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;. Aragonites and most biogenic low Mg-calcites contain significant amounts of Na&lt;sup&gt;+&lt;/sup&gt;, but very low concentrations of SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;. The SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;content of non-biogenic calcites and aragonites investigated was below 100 ppm. The presence of Na&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;and SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;increases the unit cell size of calcites. The solid-solutions show a solubility minimum at about 0.5 mole percent SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;beyond which the solubility rapidly increases. The solubility product of calcites containing 3 mole percent SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;is the same as that of aragonite. Na&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;appears to have very little effect on the solubility product of calcites. The amounts of Na&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;and SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;incorporated in calcites vary as a function of the rate of crystal growth. The variation of the distribution coefficient (&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;D&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;D&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;) of SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;in calcite at 25.0°C and 0.50 molal NaCl is described by the equation&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;D = k&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;+ k&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;R&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;D = k&lt;sub&gt;0&lt;/sub&gt;+ k&lt;sub&gt;1&lt;/sub&gt;R&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;where&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;k&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/msub&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;k&lt;sub&gt;0&lt;/sub&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;/sub&gt;and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="math"&gt;&lt;span id="MathJax-Element-4-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;mtext&gt;k&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/msub&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;k&lt;sub&gt;1&lt;/sub&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;are constants equal to&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="math"&gt;&lt;span id="MathJax-Element-5-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;mtext&gt;6.16 &amp;amp;#xD7; 10&lt;/mtext&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;&amp;amp;#x2212;6&lt;/mn&gt;&lt;/msup&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;6.16 × 10&lt;sup&gt;−6&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="math"&gt;&lt;span id="MathJax-Element-6-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;mtext&gt;3.941 &amp;amp;#xD7; 10&lt;/mtext&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;&amp;amp;#x2212;6&lt;/mn&gt;&lt;/msup&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;3.941 × 10&lt;sup&gt;−6&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;, respectively, and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="math"&gt;&lt;span id="MathJax-Element-7-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;mtext&gt;R&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;R&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;is the rate of crystal growth of calcite in mg·min&lt;sup&gt;−1&lt;/sup&gt;·g&lt;sup&gt;−1&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;of seed. The data on Na&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;are consistent with the hypothesis that a significant amount of Na&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;occupies interstitial positions in the calcite structure. The distribution of Na&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;follows a Freundlich isotherm and not the Berthelot-Nernst distribution law. The numerical value of the Na&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;distribution coefficient in calcite is probably dependent on the number of defects in the calcite structure. The Na&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;contents of calcites are not very accurate indicators of environmental salinities.&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(85)90166-8</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Kinetic and thermodynamic factors controlling the distribution of SO32- and Na+ in calcites and selected aragonites</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>