中文摘要：

地层年龄模式的建立是古海洋研究的基础,由于南大洋高纬度地区生物碳酸钙保存差,限制了有孔虫AMS14 C测年和氧同位素地层学方法的应用,需要寻找替代方法。通过中国第30次和29次南极考察航次在普里兹湾海域采集的ANT30/P1-02、ANT30/P1-03、ANT29/P5-03岩心的高分辨率磁化率扫描,XRF岩心元素扫描,结合浮游有孔虫AMS14 C测年等分析发现,Baxs的变化与冰期-间冰期气候变化具有很好的对应关系,是输出生产力的良好替代指标,其变化模式指示了气候变化。基于此,将这3个岩心中的Baxs与深海底栖有孔虫氧同位素标准曲线（LR04-δ18 O）进行对比,建立了高分辨率的地层年代模式。经过Baxs与LR04-δ18 O的交叉小波分析结果显示,两者在轨道周期上都具有显著的相关关系;同时,Baxs年龄模式与该岩心相对古地磁强度方法所建立的地层年龄模式相吻合,验证了该地层年龄模式的合理性和可靠性。根据ANT30/P1-02所建立的地层年代模式,普里兹湾陆坡扇晚第四纪沉积序列的平均沉积速率在0.15~4.76cm/ka之间,平均为1.18cm/ka。其平均沉积速率与ODP1167站位上部的平均沉积速率一致（1.00cm/ka）。该区沉积速率在冰期末期开始快速增高,在冰消期或间冰期初期时达到最高,之后又不断降低。冰消期沉积具一定的层理构造,而冰期和间冰期沉积无明显层理构造。普里兹湾陆坡扇晚第四纪沉积物磁化率与气候之间没有明确的响应关系,使用磁化率与冰心风尘相对比来建立地层年龄模式的方法不适用于该海域。

英文摘要：

A precise age model of a marine sediment sequence is essential for paleoceanographic reconstruction.It is critical to find out effective dating methods for sediments in high latitudes of the Southern Ocean as poor preservation of carbonates has limited the application of the widely used oxygen isotope stratigraphic methods.Here,we conducted high resolution magnetic susceptibility（MS）core scanning,X-ray fluorescence（XRF）core scanning and planktonic foram AMS 14 C dating on cores of ANT29/P5-03,ANT30/P1-03,and ANT30/P1-02 collected from Prydz Trough Mouth Fan,East Antarctica during the29 th and the 30 th Chinese National Antarctic Research Expeditions by R/V Xuelong,and found that Baxsis a reliable proxy for the paleo-export productivity of surface waters in the study area,which varies with global and East Antarctic climate at orbital scale.So age model of sediment sequence can be constructed by matching the Baxsof the sediment sequence to LR04 oxygen isotope stack[21].We constructed the age model of ANT30/P1-02 following above method and found that the sedimentation rate of ANT30/P1-02 ranges between 0.15 to 4.76cm/ka with a mean of 1.18cm/kyr which is similar to the average sedimentation rate of the upper strata of core ODP1167.The highest sedimentation rate of a whole glacial cycle occurs at deglacial period.Interglacial period has relatively higher average sedimentation rate than glacial period.Correspondingly,strata of deglacial periods have bedding structures.Interglacial sediments are brighter than glacial sediments though both of glacial and interglacial sediments are massive.MS signal of sediment at the study area appears to have arbitrarily responded to the global and the local climate changes.So the strategy to construct age model of marine sediment sequences by correlating the MS signal of sediments to dust concentrations of ice cores are inapplicable at Prydz Bay area.