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a line on an isotope ratio diagram denoting a suite of rock or mineral samples all formed at the same time. The slope of the line is related to the age of the rock or mineral suite
a line or curve on a geological map or cross section (esp of oceanic crust) connecting points of identical age
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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