Oxygen Isotope Composition of Subglacially Precipitated Calcite: Possible Paleoclimatic Implications

Abstract

Isotopic analyses of subglacially precipitated calcite from near a modern temperate glacier show that the δ¹⁸O (= ¹⁸O/¹⁶O relative to standard mean ocean water) of the calcite records the δ¹⁸O of the ice from that glacier. It may therefore be possible to determine the δ¹⁸O of Pleistocene ice sheets on the basis of isotopic analyses of calcite formed under that ancient ice. This, in turn, would allow estimation of the δ¹⁸O of Pleistocene oceans and correction of the paleotemperature scale based on foraminiferal oxygen isotopic analyses.