{'fraction_non_alphanumeric': 0.06508549365692223, 'fraction_numerical': 0.07391064533921676, 'mean_word_length': 5.478571428571429, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A 4500-YEAR HIGH-RESOLUTION CLIMATIC RECORD FROM A STALAGMITE IN XINYA CAVE,CHONGQING,CHINA

A 145mm long stalagmite(XY6) from Xinya cave in northeastern Chongqing,a site under influence of both East Asian monsoon and Indian monsoon,has been ICP-MS ~(230) Th/U dated.Depositional characteristics and five ~(230) Th/U dates show that the stalagmite deposited over the past 4500a but ceased about 220a ago,with an average growth of 0.035mm/a ranging from 0.016mm/a to 0.068mm/a.The white gray zones deposited faster,whereas dark brown zones grew slower.We have analyzed 102 samples for δ~(18)O and δ~(13)C,revealing decadal-to-centennial climate changes during the past 4500a.The δ~(13)C fluctuated from-4‰ to-10‰ while the δ~(18)O fluctuated from-6‰ to-8‰(PDB),showing positive correlation on decadal-to-centennial scales.Speleothem δ~(18)O in eastern China including our study area can be used as a proxy of summer monsoon strength,with lighter values indicating stronger summer monsoon and higher precipitation.Speleothem δ~(13)C,on the other hand,can be used as a proxy of paleo-vegetation,with lighter values indicating higher C3/C4 plant ratios and good vegetations,and vice versa.The positive correlation of δ~(18)O and δ~(13)C may indicate warm-wet and cold-arid paleoclimate patterns in this area.Based on the δ~(18)O and δ~(13)C variation,the paleoclimate in the past 4500a can be divided into 3 warm-wet periods: 4500~4100a,3200~2500a,1850~1500a and 3 cold-arid periods: 4100~3200a,2500~1850a,500~50a,respectively.A sharp increase of ~(18) O occurred around 4100 a B.P.and kept relatively heavy values after then,perhaps indicating a decrease of the Summer Monsoons since 4.1ka.The enriched ~(18)O values between 500~250a might reflect colddry conditions in this area corresponding to the Little Ice Age.