MODERN CLIMATIC SIGNALS DEDUCED FROM STABLE ISOTOPE IN SHELLS IN XINGCUO LAKE SEDIMENTS,EAST TIBETAN PLATEAU,CHINA

Xingcuo lake,a closed one,is situated in eastern Tibetan Plateau.There are abundant snail shells Gy-raulus sibirica in its sediments.Here we display the determining results ofδ 13 C,δ 18 O in shell Gyraulus sibirica continuous-ly preserved in Xincuo Lake sediment s in the recent 50years.And by coupling the indexes ofδ 13 C,δ 18 O and instrumen-tal meteorological data in its basin to build relative function relation s among them,we probe quantitatively climatic sig-nals recorded in those indexes.The r esults show that there are remarkabl e relations betweenδ 13 C proxy and precipitation,δ 18 Oproxy and air temperature,of which correlative coefficient was 0.89an d 0.71,respectively.Besides,we also demon-strated that average variation betw eenδ 13 C proxy and precipitation(dδ 13 C /dP)was 0.027‰/mm and 1.64‰/℃forδ 18 O and air temperature(dδ 18 O /dT).