A possible Younger Dryas-type event during sian monsoonal Termination 3

作者：Chen Shitao; Wang Yongjin^*; Kong Xinggong; Liu Dianbing; Cheng Hai; Edwards R L

来源：Science in China - Series D: Earth Sciences , 2006, 49(9): 982-990.

DOI：10.1007/s11430-006-0982-4

• stalagmite
• Termination 3
• Asian monsoon
• YD-type event
• Shennongjia
• Hubei Province

Seven U-Th dates, 560 delta O-18 data and microscopic sequences were measured for stalagmites from two high-altitude caves in Shennongjia area, Hubei Province. Variations of the decadal-resolution stalagmite delta O-18 record from Swan Cave (1600 m elevation) reflect large spatial changes in circulation strength and precipitation of Asian monsoon. The evidence comes from a great similarity among the stalagmite delta O-18 records from Nanjing, Jiangsu Province; Libo, Guizhou Province and here studied area during the last deglaciation, including a part interval of Younger-Dryas event and Bolling-Allerod. A 30-year-resolution stalagmite delta O-18 record from Yongxing Cave (1400 m elevation), 70 km away from Swan Cave, reveals a rapid transition of Asian monsoon climate during Termination 3 at about 245 +/- 5 kaBP. Based on 3 U-Th dates and about 5000 continuous annual bands, a millennial dry episode has been observed during Asian monsoonal Termination 3 from the Yongxing delta O-18 profile. With respect to its structure, duration and transition, the dry reversal, as indicated by our stalagmite delta O-18 record, generally agrees with the pattern of the YD event well-expressed in the Chinese stalagmite delta O-18 records. This YD-type event is characterized by a large decrease in 5180 value as much as 2.30 parts per thousand, more than half of the delta O-18 excursion between glacial/interglacial periods, and lasts 1371 +/- 59 a determined by the annual counting chronology. After this event, the monsoon climate shifted abruptly into the interglacial period within 74 4 a. Our data corroborate the view that the repeated occurrence of YD-type event was not an "accident", possibly resulted from the coupling of ice-sheet and oceanic/atmospheric circulations.

• 出版日期2006-9
• 单位南京师范大学