<?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.M. Titterington</dc:contributor>
  <dc:creator>K.R. Ludwig</dc:creator>
  <dc:date>1994</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;If analytical errors are responsible for the scatter of points on a&amp;nbsp;&lt;/span&gt;&lt;sup&gt;230&lt;/sup&gt;&lt;span&gt;Th-&lt;/span&gt;&lt;sup&gt;234&lt;/sup&gt;&lt;span&gt;U-&lt;/span&gt;&lt;sup&gt;238&lt;/sup&gt;&lt;span&gt;U isochron diagram, the isochron should be fitted by a technique that&lt;/span&gt;&lt;span class="list-label"&gt;1.&lt;/span&gt;&amp;nbsp;weights the points according to their analytical errors and error correlations, and&lt;/p&gt;&lt;ul class="list"&gt;&lt;li class="react-xocs-list-item"&gt;&lt;span class="list-label"&gt;2. &lt;/span&gt;either takes into account the presence of some of the same data in two coupled&amp;nbsp;&lt;i&gt;XY&lt;/i&gt;&amp;nbsp;isochrons or (equivalently) uses a single, three-dimensional&amp;nbsp;&lt;i&gt;XYZ&lt;/i&gt;&amp;nbsp;isochron.&lt;/li&gt;&lt;/ul&gt;&lt;p&gt;&lt;span&gt;A method based on maximum-likelihood estimation is presented that fulfills these requirements, and the relevant equations for errors in age and initial &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;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;&lt;sup&gt;234&lt;/sup&gt;U&lt;sup&gt;238&lt;/sup&gt;U&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;are given. Equations for estimating the necessary isotope-ratio errors and error-correlations for both alpha-spectrometric and mass-spectrometric data are also developed.&lt;/span&gt;&lt;br&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/0016-7037(94)90229-1</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Calculation of 230ThU isochrons, ages, and errors</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>