摘要
渐新世初期,南极大陆在短时间内出现永久性冰盖,地球由两极无冰进入到单极有冰的特殊时期。越来越多的研究表明,这一重大气候转型事件与大气CO2及大洋碳储库的变化密切相关。南大西洋ODP 1263站碳酸钙软泥的粒度分析揭示了在渐新世初期发生的强烈碳酸盐溶解事件,碳酸盐溶解超前于底栖有孔虫氧同位素重值约100 ka,显示碳酸盐溶解事件先于南极冰盖的形成。由于碳酸钙泵的作用,碳酸盐的溶解会消耗大量的大气CO2,从而可能驱动了气候的快速变冷,导致南极大陆永久性冰盖发育。
The first continent-wide Antarctic ice sheet formed in the earliest Oligocene, during which the Earth underwent a great change from a non-glaciated planet to a polar glaciated planet. Recent investigations suggested that the mechanism of this climate transition has a close relationship with variations of ocean carbon reservoir and atmospheric CO2. The grain size variations of the carbonate ooze at ODP Site 1263 in South Atlantic revealed that a very strong carbonate dissolution event happened in the Earliest Oligocene. Leading the heaviest foraminiferal δ^18O by 100 ka, the carbonate dissolution event started earlier than formation of the Antarctic ice sheet. The carbonate dissolution consumes lots of atmospheric CO2 and then transports the atmospheric CO2 into deep sea through the function of calcium pump. It could force and speed up the global cooling, and then the permanent ice sheet appeared on the eastern Antarctic.
出处
《地球科学进展》
CAS
CSCD
北大核心
2006年第8期800-805,共6页
Advances in Earth Science
基金
国家自然科学基金项目"南大西洋渐新世初大冰期事件的高分辨率研究"(编号:40446003)
"南海中更新世气候转型期千年尺度气候波动及其全球意义"项目(编号:40331002)
"西太平洋暖池与东亚古环境:沉积记录的海陆对比"项目(编号:40321603)
霍英东教育基金会项目"青藏高原东部晚第四纪侵蚀和气候演变在南海中的记录"项目(编号:101018)
教育部新世纪优秀人才支持计划"早新生代极端气候事件的海陆对比研究"项目
科技基础性工作和社会公益研究专项"中国综合大洋钻探计划预研究"(编号:2003DIB3J114)资助
