杭州湾北岸全新世早期(10-9 cal ka BP)高精度海平面重建及沉积环境响应

面对海平面加速上升和入海泥沙减少的双重压力，研究气候-海平面变化的机制及其对海岸带生态、环境的影响成为热点课题。重建全新世海平面是揭示过去全球变化中河口海岸地区沉积环境响应过程的重要基础，也是预测未来海平面变化的重要依据。本申请课题拟利用长江三角洲地区全新世地层底部普遍存在的盐沼和潮滩相沉积，在基底泥炭的基础上，利用多指标地层学方法（岩性、粒度、微体古生物化石、TOC/TN、TOC/TS和自生铁硫化物）准确识别划分钻孔潮滩沉积微相，建立更具普适性的海平面标尺。另外，拟从常规测年样品中挑选具有指示意义的特征生物遗体用于AMS14C测年，以提高数据的精确性；同时，针对海平面重建测年材料稀缺的特点，本研究拟提取潮滩沉积微相中的原生微体古生物特征种丰富测年材料，提高古海平面重建的年代分辨率，重建杭州湾北岸全新世早期海平面曲线；并讨论沉积环境对海平面波动的响应。

A high-resolution Holocene sea level curve is important to study past coastal sedimentary environmental evolution and predict future sea level change and coastal response, as river sediment decline and sea level rising accelerate persistently. This proposing program intends to comply a systematic research on the Holocene sedimentary record in the northern coast of Hangzhou Bay. Multiple proxies will be employed for distinguishing sedimentary microfacies of tidal flat, including sediment lithology, grain size analysis, microfossils, TOC/TN, TOC/TS and authengenic iron sulfide. The local tidal range will be considered to reconstruct paleo sea level fluctuation on the basis of a high resolution chronological sequence, which is provided by both local tidal microfossils and basal peat AMS 14C dating. Furthermore, the sedimentary environment response of tidal flat to the sea level rise will be referred to discuss by contrasting sediment accumulation rate and sea level rise rate.