在千年及轨道时间尺度上，边缘陆坡沉积区有机碳埋藏在海洋碳循环和全球气候变化中扮演重要角色。然而，陆坡沉积区有机碳埋藏的时空演变机制尚不清楚。这主要受限于如下两个难点问题：第一，如何更准确的量化区分海源和陆源有机碳的贡献；第二，缺乏可靠的沉积有机质埋藏效率替代指标。本申请聚焦在冲绳海槽与毗邻琉球群岛东侧典型陆坡沉积区，通过测定多个沉积序列中有机生物标志物单体δ13C和Δ14C以及多参数生物标志物等记录，利用三端元混合模型量化末次冰盛期以来冲绳海槽沉积有机碳来源、相对贡献及其时空变化规律；另外，同时测定活性磷等输出生产力指标和环境敏感型金属元素记录，结合上述有机碳埋藏记录甄别末次冰盛期以来冲绳海槽沉积有机碳埋藏变化的调控机制。最终，通过解剖冲绳海槽典型陆坡沉积区有机碳埋藏特征与机制，为研究全球其它边缘海盆及陆坡区沉积有机碳埋藏提供参考。

Organic carbon burial plays an important role in regulating marine carbon cycle and global climate changes on orbital and millennial time scales. However, the variability of organic carbon burial might be environment-specific, especially in marginal seas occupied by large variability of primary productivity and distinctive environmental factors; and our understanding on mechanisms that controlling organic carbon burial therein remains ambiguous. By carrying out measurements on stable (13C) and radiogenic (14C) carbon isotopes of marine and terrestrial compound-specific biomarkers from sediment cores that located in the middle Okinawa Trough and the adjacent Ryukyu Islands slop, this study aims to estimate the contributions and temporal variations of marine and terrestrial organic carbon burial flux over the last 24 kyr. Combined with redox sensitive metal elements and export productivity records from the same cores, effort will be focused on the mechanisms controlling organic carbon burial in the middle Okinawa Trough. Results from this study are expected to provide references for the study of organic carbon buried in the western Pacific margin seas.