Recontructing East Asian monsoon climate history between 12.5 and 7 Ma: Linkages to tectonic events, cryosphere evolution and orbital forcing

中新世中期至晚中新世气候向现代边界条件的过渡仍然没有得到很好的解决，这主要是因为缺乏连续的、年代准确的气候档案。我们建议重建东亚气候变率，并研究季风演化对构造事件、冰冻圈演化和中新世12.5-7 Ma轨道强迫的响应。我们的主要目标是：1)在南中国海ODP1146站建立高分辨率的轨道调谐年代学，在那里恢复了扩大的、连续的碳酸盐沉积序列；2)提供气候和海洋化学指标的综合(主要是底栖和浮游的δ18O、δ13C，辅之以镁/钙、碳酸盐溶解指数和动物普查计数)，将重点放在表层和底层水团的时间演化上。我们将针对主要气候变化的阶段，如中新世晚期冰川生长事件(Miller等人的MI5-MI7,1991)和与喜马拉雅抬升有关的~8 Ma季风强度的推断变化。这项工作将为南中国海提供一个必要的年代学框架，并提供一个关于东亚气候和季风变率的高分辨率多指标调查。

The Middle to Late Miocene climate transition towards modern boundary conditions is stillpoorly resolved, mainly due to the scarcity of continuous, well-dated climate archives. Wepropose to reconstruct East Asian climate variability and investigate monsoonal evolution inresponse to tectonic events, cryosphere evolution and orbital forcing over the Mioceneinterval 12.5 -7 Ma. Our primary targets are: 1) to develop a high-resolution, orbitally-tunedchronology in South China Sea ODP Site 1146, where an expanded, continuous carbonaterichsedimentary succession was recovered and 2) to provide a synthesis of climate andocean chemistry proxies (principally benthic and planktic δ18O, δ13C supplemented by Mg/Ca,carbonate dissolution indices and faunal census counts) that will focus on the temporalevolution of surface and bottom water masses. We will target phases of major climaticchange such as the Late Miocene ice growth events (Mi5-Mi7 of Miller et al., 1991) and theinferred change in monsoon intensity at ~ 8 Ma associated with Himalayan uplift. This workwill supply an essential chronological framework for the South China Sea, and provide ahigh-resolution multiproxy investigation of East Asian climate and monsoon variability.