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利用三峡库区丰都羊子洞石笋(Y02)230 Th测年数据和碳同位素建立了65~90ka BP时段平均分辨率为46a的石笋碳同位素时间序列.羊子洞石笋碳同位素记录显示,季风变化在MIS5b向MIS5a转变过程中是渐变模式,并且D/O21事件呈现双峰结构不同于山宝洞石笋记录和万象洞石笋记录,这可能与羊子洞所处的地理位置和分辨率有关.石笋Y02的δ13 C记录并未记录72ka BP左右的降温事件.对石笋碳同位素进行功率谱分析发现,石笋Y02的δ13 C记录主要存在290,229,196,115,100和93a等周期,与太阳活动周期相吻合;Y02碳同位素记录与北半球太阳辐射曲线变化趋势一致,进一步证明了末次间冰期-末次冰期东亚季风区气候变化直接响应与北半球太阳辐射的假说.
The carbon isotope time series of stalagmite with an average resolution of 46a at 65 ~ 90ka BP were established using dating data of 230 Th stalagmite of Yantai Cave in Fengdu, the Three Gorges Reservoir area. The transition from MIS5b to MIS5a is gradual and the bimodal structure of D / O21 event is different from the records of stalagmite in Shantou cave and the stalagmite of Vientiane cave, which may be related to the geographical location and resolution of the puppet cave. The δ13C record did not record the temperature drop event of about 72ka BP.Statistical analysis of the stalagmite carbon isotope showed that the δ13C record of stalagmite Y02 mainly existed in cycles of 290, 229, 196, 115, 100 and 93a, which coincided with the period of solar activity. The Y02 carbon isotope record The consistent trend of solar radiation curve further proves the hypothesis that the last interglacial - the last glacial East Asian monsoon climate change direct response and the northern hemisphere solar radiation.