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造成深海沉积物中碳酸盐含量受气候控制而变动的原因依旧是一个没有肯定的、有争论的课题。有三个变化因素:生物成因碳酸盐的供应量,溶解作用造成的损失,和非碳酸盐相的稀释作用。本文提出在海洋中以恒定产率产生的~(230)Th 对测定区域性沉积率的变化提供了一个可靠的参考标准。根据对己公布资料的初步分析结果表明,在北大西洋岩芯的溶跃面深度和该深度以上观察到的碳酸盐含量的变动主要由于陆源粘土输入量变化之故,陆源粘土在冰期的输入量比间冰期高2至5倍。在冰期内碳酸盐的沉积似乎有所减少,但减少量不超过1/2。已经发表的~(230)Th/~(232)Th 曲线图表明:在冰期内南大西洋陆源粘土的输入量也有所增加。
The reason why the carbonate content in deep-sea sediments is subject to climate change is still a subject that is not affirmed and debated. There are three variables: biogenic carbonate supply, loss due to dissolution, and dilution with non-carbonate phases. This paper proposes that ~ (230) Th produced in the ocean at a constant yield provides a reliable reference for the determination of regional deposition rate changes. Based on preliminary analysis of published data, it is shown that variations in the carbonate content observed above the surface depth of the North Atlantic core and above this depth are mainly due to changes in the input of terrestrial clay. The input of terrigenous clay during the glacial period The amount is 2 to 5 times higher than in the glacial period. Carbonate deposition appears to have decreased during the glacial period, but the reduction did not exceed 1/2. The published ~ (230) Th / ~ (232) Th plot shows that the input of terrestrial clay in the South Atlantic has also increased during the glacial period.