Carbonate Deposition Rates from Cretaceous to present

1.数据基础参考了各项目钻探岩心的全球沉积速率、岩心密度、氧碳稳定同位素比值和岩心化学浓度的初步报告和科学成果。将白垩纪至今50万年间深海海底和陆地上的沉积速率相加，得到了碳酸盐等组分的全球平均通量。白垩纪和新近纪全球碳酸盐沉积速率较高，而白垩纪和晚第三纪碳酸盐沉积速率较低。值得注意的是，从上中新世到更新世，它们处于极高的水平。基于碳、锶循环模型的计算表明，喜马拉雅和青藏高原的风化作用比火山作用更重要。2.岩心样品的化学分析用X射线荧光光谱、碳酸盐弹、有机质含量和生物硅质等方法研究了ODP159航段、959D站位白垩纪至今的岩心样品的化学成分。由于大西洋局部环境的变化，很难将该岩心碳酸盐沉积速率的趋势与全球沉积速率的趋势联系起来。

1.Data BaseInitial Reports and Scientific Results of the ODP and DSDP were referred to collect global depositional rates, core density, oxygen and carbon stable isotope ratio, and chemical concentration of core samples drilled at each project. We obtain the global mean flux of carbonate and other components by adding the accumulation rates on deep-sea floors and those on continents at the duration of 0.5 million year from Cretaceous to present. The global carbonate accumulation rates were high in the Cretaceous and Neogene, while those in the Pateogene were low. It is noteworthy that they were extremely high from Upper Miocene to Pleistocene. Calculation based on the carbon and Sr circulation model suggest that weathering at the Himalayan and Tibetan Plateau was more important than that of volcanism.2.Chemical analysis of core samplesChemical contents of the core samples drilled during the ODP Leg 159, Site 959D from Cretaceous to present were investigated by XRF, carbonate bomb, organic contents, and biogenic silica methods. It is difficult to correlate the trend in the carbonate deposition rate of this core to those in global accumulation rates due to the local environmental changes in the Atlantic.