摘要
海洋沉积物的天然热释光强度的变化特征和冰期、间冰期的旋回有良好的对应关系,表明海洋沉积物的天然热释光强度可以指示古海洋气候的变化.本研究取自日本南海海槽增生楔的IODP C0004C岩芯样品由更新统和下-中上新统沉积物组成.样品的热释光测量结果与生物壳体碳酸钙含量、重结晶方解石含量对比后发现,热释光强度与生物壳体碳酸钙含量变化呈负相关,与重结晶方解石含量变化呈正相关,天然热释光强度的高值区与间冰期对应,低值区与冰期对应,根据岩芯样品热释光特征,在岩芯中划分出三个间冰期和三个冰期.根据热释光与磁化率的对比分析,结合岩性观察,推测岩芯中IIA段的角砾岩为陆源物质.鉴于样品物质组成、来源的差异性及热释光信号的敏感性,建议在利用海洋沉积物的天然热释光进行古气候和古沉积环境研究时,应选取地质作用过程比较简单、沉积环境相对稳定的地区.
Natural thermoluminescence（ NTL） from ocean sediments is a good indicator for the paleoclimate evolution because the variation of NTL is corresponding to the glacial change. Sedimentary age of the core IODP C0004 C in Nankai Trough is early-late Pleistocene and early-middle Pliocene. NTL of 120 samples from the core were measured. The result shows NTL has a negative correlation with the content of Ca CO3 and has positive correlation with the content of calcite. The high and low NTL correspond to the interglacial and glacial stages,respectively. Three interglacial and 3 glacial stages were divided according to the feature of NTL of the core. The breccia in IIA of the core is supposed to be terrigenous sediment according to comparison of NTL with magnetic susceptibility. It is suggested that when NTL of sediments is used to study paleoclimate,the areas with relatively simple geological process and stable sedimentary environment should be chosen firstly.
出处
《应用海洋学学报》
CAS
CSCD
北大核心
2015年第1期34-40,共7页
Journal of Applied Oceanography
关键词
海洋环境科学
天然热释光
古气候
日本南海海槽
碳酸钙
磁化率
marine environmental science； natural thermoluminescence； paleoclimate； Nankai Trough； CaCO3； magnetic susceptibility
