A Neoproterozoic snowball earth
A Neoproterozoic snowball earth
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DOI：
10.1126/science.281.5381.1342
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发表时间：
1998-08-28
期刊：
影响因子：
56.9
通讯作者：
Schrag, DP
中科院分区：
文献类型：
--
作者：
Hoffman, PF;Kaufman, AJ;Schrag, DP
负碳同位素异常的碳酸盐岩包围新元古代冰川沉积物在纳米比亚，结合热沉降历史的估计，表明在海洋表面的生物生产力崩溃了数百万年。这种崩溃可以用全球冰川作用（即雪球地球）来解释，当陆上火山释气将大气中的二氧化碳提高到现代水平的350倍时，全球冰川作用突然结束。快速终止将导致雪球地球变暖到极端的温室条件。大气中的二氧化碳向海洋的转移将导致碳酸钙在温暖的表层沃茨中迅速沉淀，产生全球观测到的碳酸盐岩帽。
Negative carbon isotope anomalies in carbonate rocks bracketing Neoproterozoic glacial deposits in Namibia, combined with estimates of thermal subsidence history, suggest that biological productivity in the surface ocean collapsed for millions of years. This collapse can be explained by a global glaciation (that is, a snowball Earth), which ended abruptly when subaerial volcanic outgassing raised atmospheric carbon dioxide to about 350 times the modern Level. The rapid termination would have resulted in a warming of the snowball Earth to extreme greenhouse conditions. The transfer of atmospheric carbon dioxide to the ocean would result in the rapid precipitation of calcium carbonate in warm surface waters, producing the cap carbonate rocks observed globally.