Oxygen isotopes in meteoric calcite cements as indicators of continental paleoclimate

Because meteoric water 18 O values decrease with decreasing ambient temperature and increasing latitude, 18 O values of meteoric calcite cement should exhibit a similar relation with paleolatitude and be an indicator of continental paleotemperatures. To test this, we compiled isotopic and paleolatitude data for 20 meteoric cements and nine speleothems ranging in age from Devonian to modern and in paleolatitude from 3.5 to 83. Mean 18 O values for meteoric cements and speleothems both show the same negative correlation with paleolatitude. If it is assumed that the modern meteoric water 18 O vs. temperature relation is valid for the past and that insignificant evaporation occurred prior to carbonate precipitation, then coastal and inland paleotemperatures can be calculated from the 18 O values of meteoric calcite and seawater. -from Authors

Oxygen isotopes in meteoric calcite cements as indicators of continental paleoclimate Academic Article