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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>R. K. O’Nions</dc:contributor>
  <dc:contributor>N.S. Belshaw</dc:contributor>
  <dc:contributor>A. Gibb</dc:contributor>
  <dc:contributor>J.R. Hein</dc:contributor>
  <dc:creator>F. Von Blanckenburg</dc:creator>
  <dc:date>1996</dc:date>
  <dc:description>&lt;p&gt;The direct measurement of the ratio of cosmogenic&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;10&lt;/sup&gt;Be (&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;T&lt;/mtext&gt;&lt;mtext&gt;1&lt;/mtext&gt;&lt;mtext&gt;2&lt;/mtext&gt;&lt;mtext&gt;= 1.5 Ma&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;T12= 1.5 Ma&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;) to stable terrigenously sourced&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;9&lt;/sup&gt;Be in deep seawater or marine deposits can be used to trace water mass movements and to quantify the incorporation of trace metals into the deep sea. In this study a SIMS-based technique has been used to determine the&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;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;9&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;10Be9Be&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;ratios of the outermost millimetre of hydrogenetic ferromanganese crusts from the worlds oceans.&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;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;9&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;10Be9Be&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;ratios, time-corrected for radioactive decay of cosmogenic&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;10&lt;/sup&gt;Be using&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;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;234&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;U&lt;/mtext&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;238&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;U&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;234U238U&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;, are in good agreement with AMS measurements of modern deep seawater. Ratios are relatively low in the North and equatorial Atlantic samples (0.4–0.5 × 10&lt;sup&gt;−7&lt;/sup&gt;). In the Southwest Atlantic ratios increase up to 1 × 10&lt;sup&gt;−7&lt;/sup&gt;, they vary between 0.7 and 1.0 × 10&lt;sup&gt;−7&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;in Indian Ocean samples, and have a near constant value of 1.1 ± 0.2 × 10&lt;sup&gt;−7&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;for all Pacific samples.&lt;/p&gt;&lt;p&gt;If the residence time of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;10&lt;/sup&gt;Be (&lt;i&gt;τ&lt;/i&gt;10&lt;sub&gt;Be&lt;/sub&gt;) in deep water is constant globally, then the observed variations in&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;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;9&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;10Be9Be&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;ratios could be caused by accumulation of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;10&lt;/sup&gt;Be in deep water as it flows and ages along the conveyor, following a transient depletion upon its formation in the Northern Atlantic. In this view both&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;10&lt;/sup&gt;Be and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;9&lt;/sup&gt;Be reach local steady-state concentration in Pacific deep water and the global&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;&amp;amp;#x3C4;10&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;&amp;amp;#x224C; 600&lt;/mtext&gt;&lt;mtext&gt;a&lt;/mtext&gt;&lt;/math&gt;"&gt;≌&lt;span class="MJX_Assistive_MathML"&gt;τ10Be≌ 600a&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;. An alternative possibility is that the Be isotope abundances are controlled by local scavenging. For this scenario&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;τ&lt;/i&gt;10&lt;sub&gt;Be&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;would vary according to local particle concentration and would ≌ 600 a in the central Pacific, but&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;&amp;amp;#x3C4;10&lt;/mtext&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;/mn&gt;&lt;/msub&gt;&lt;mtext&gt;&amp;amp;#x224C; 230&lt;/mtext&gt;&lt;mtext&gt;a&lt;/mtext&gt;&lt;/math&gt;"&gt;≌&lt;span class="MJX_Assistive_MathML"&gt;τ10Be≌ 230a&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;in the Atlantic.&lt;/p&gt;&lt;p&gt;Mass balance considerations indicate that hydrothermal additions of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;9&lt;/sup&gt;Be to the oceans are negligible and that the dissolved riverine source is also small. Furthermore, aeolian dust input of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;9&lt;/sup&gt;Be appears insufficient to provide the dissolved&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;9&lt;/sup&gt;Be inventory. The dissolution of only a small proportion (2%) of river-derived particulates could in principle supply the observed seawater&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;9&lt;/sup&gt;Be content. If true, ocean margins would be the sites for&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;9&lt;/sup&gt;Be addition. Due to the particle-reactive nature of Be, these would also be the primary sites of Be removal. A possible net result of horizontal water masses passing through these marginal areas might be a decrease in seawater&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="math"&gt;&lt;span id="MathJax-Element-8-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;9&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;10Be9Be&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;, and establishment of a relatively constant&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;9&lt;/sup&gt;Be concentration.&lt;/p&gt;&lt;p&gt;As&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;τ&lt;/i&gt;10&lt;sub&gt;Be&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;(∼ 600 a) is less than the apparent age of deep water in the Pacific (∼ 1500 a), the Pacific record of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="math"&gt;&lt;span id="MathJax-Element-9-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;9&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;10Be9Be&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;is not expected to show secular variations due to changes in deep-water flow, despite the large variations in&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="math"&gt;&lt;span id="MathJax-Element-10-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;9&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;10Be9Be&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;between different water masses. Because of this insensitivity to deep-water flow, however, it is suggested that the&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="math"&gt;&lt;span id="MathJax-Element-11-Frame" class="MathJax_SVG" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;9&lt;/mn&gt;&lt;/msup&gt;&lt;mtext&gt;Be&lt;/mtext&gt;&lt;/math&gt;"&gt;&lt;span class="MJX_Assistive_MathML"&gt;10Be9Be&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;ratio, determined in the authigenic phase of marine sediments or hydrogenetic precipitates, should be a suitable tool for monitoring changes in continental input or cosmic ray intensity on longer time scales.&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/0012-821X(96)00059-3</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Global distribution of beryllium isotopes in deep ocean water as derived from Fe-Mn crusts</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>