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

中新世中期到晚期气候向现代边界条件的过渡仍然没有得到很好的解决，主要是由于缺乏连续的、日期明确的气候档案。我们建议重建12.5 - 7 Ma的东亚气候变率，并研究构造事件、冰冻圈演化和轨道强迫对季风演化的响应。我们的主要目标是：1）在中国南海ODP 1146站建立一个高分辨率的轨道调谐年代学，在那里恢复了一个扩展的、连续的碳酸盐沉积序列; 2）提供一个气候和海洋化学代用指标的综合（主要为底栖和浮游δ 18 O，δ 13 C，辅以Mg/Ca，碳酸盐溶解指数和动物群普查计数），将侧重于表层和底层水体的时间演变。我们将针对主要气候变化的阶段，如晚中新世冰生长事件（米勒等人的Mi5-Mi 7，1991），并推断出与喜马拉雅隆升有关的~ 8 Ma季风强度变化。这项工作将提供一个重要的年代框架，南中国海，并提供一个高分辨率的东亚气候和季风变率的多代理调查。

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.