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对湖北省神农架两个高海拔洞穴(天鹅洞:海拔1600m;永兴洞:海拔1400m)石笋实测了7个U-Th年龄、560个氧同位素以及年纹层厚度变化序列.天鹅洞石笋十年际分辨率δ18O曲线十分类似于江苏南京和贵州荔波石笋记录的波令暖期和新仙女木事件基本特征,表明本区石笋δ18O反映了区域性亚洲季风经向环流及其降水变化特征.相距天鹅洞约70km的永兴洞石笋高分辨率(平均30a左右)δ18O时间序列揭示了倒数第三次冰消期亚洲季风突变过程.基于3个U-Th年龄和连续5000a左右生长纹层计数结果,在245±5kaBP左右冰消期识别出一个千年级冷事件.这一事件持续时间为1371±59a,并在74±4a内快速向间冰期(MIS7e)突变,δ18O的变幅达2.30‰,相当于冰期/间冰期振幅的1/2强.这些事件特征类似于亚洲季风区石笋δ18O记录的新仙女木事件,说明新仙女木事件不是末次冰消期的一次偶然事件,很可能是第四纪冰盖、大尺度海洋/大气环流耦合作用的产物.
Seven U-Th ages, 560 oxygen isotopes and annual variations of stamen thickness were measured for two high-altitude caves (Swanhole: 1600m above sea level; Yongxing Cave: 1400m above sea level) in Shennongjia, Hubei Province. The inter-resolution δ18O curve is similar to the Permian and Neo-Nymph wood events recorded by stalagmite in Nanjing and Libo of Jiangsu Province, indicating that δ18O in this area reflects the meridional circulation of the Asian monsoon and its precipitation variation. The high resolution (about 30 a) δ18O stalagmite of the Yongxing Cave with about 70 km of Swan hole reveal the abrupt change of the Asian Peninsula over the penultimate ice age.According to the counting results of three U-Th ages and continuous lamina about 5000 a , A Millennial-class cold event was identified at 245 ± 5 kaBP, and the duration of this event was 1371 ± 59a, which was rapidly changed to MIS7e within 74 ± 4a. The amplitude of δ18O was 2.30 ‰, Which is equivalent to 1/2 of the amplitude of the glacial / interglacial period.These events are similar to the new fairy wood event recorded by stalagmite δ18O in the Asian monsoon area, indicating that the new fairy wood event is not an accidental event in the last ice-cold period and is likely to be the fourth discipline Cover, large-scale sea / air circulation Coupling products.