RELATION BETWEEN HYDROGEN ISOTOPIC-RATIOS OF BONE-COLLAGEN AND RAIN

The hydrogen isotopic value (deltaD) of deer bone collagen is related to both deltaD of rain during the growing season and growing season relative humidity (RH). With correction for the effects of RH, bone deltaD is related to growing season rain deltaD in a simple manner with a slope of 1.0. This indicates that, with RH correction, there are no additional sources of bias in the deltaD of bone due to unaccounted for biologic or climatic effects. Due to a low sensitivity of bone deltaD to RH effects, both yearly and growing season rain deltaD can be estimated with considerable accuracy (R = 0.97 and R = 0.96) from bone collagen deltaD and deltaN-15. Here, deltaN-15 is used to correct bone deltaD for the effects of RH. From these estimates of rain deltaD, it may then be possible to evaluate temperature since the deltaD of rain primarily reflects local temperature. Therefore, the measurement of bone collagen deltaD has good potential for evaluating paleoclimates.