ANOMALOUS C-13 ENRICHMENT IN MODERN MARINE ORGANIC-CARBON
ANOMALOUS C-13 ENRICHMENT IN MODERN MARINE ORGANIC-CARBON
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DOI：
10.1038/315216a0
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发表时间：
1985-01-01
期刊：
影响因子：
64.8
通讯作者：
CLAYPOOL, GE
中科院分区：
文献类型：
--
作者：
ARTHUR, MA;DEAN, WE;CLAYPOOL, GE
海相有机碳同位素（富集13C）比大多数陆生植物或陆相有机碳重。因此，现代海相沉积物中有机C的δ13C值通常根据保存的有机物的海相和陆相来源的相对比例来解释2,3。当使用独立的地球化学技术评估白垩纪或更古老岩石的有机质来源时，发现主要含海相有机C的岩石通常比主要含陆相有机C的岩石具有更轻（更负）的δ13C值。因此，我们得出结论，白垩纪中期和更早海洋的海洋光合作用通常导致C同位素分异更大，产生的有机C具有更轻的δ13C值。现代海洋光合作用可能发生在不寻常的地质条件下（海洋初级生产速率较高，较低），这些地质条件限制了溶解二氧化碳的可用性，并使碳同位素分馏最小化。
Marine organic carbon is heavier isotopically (13C enriched) than most land-plant or terrestrial organic C1. Accordingly,δ13C values of organic C in modern marine sediments are routinely interpreted in terms of the relative proportions of marine and terrestrial sources of the preserved organic matter2,3. When independent geochemical techniques are used to evaluate the source of organic matter in Cretaceous or older rocks, those rocks containing mostly marine organic C are found typically to have lighter (more-negative)δ13C values than rocks containing mostly terrestrial organic C. Here we conclude that marine photosynthesis in mid-Cretaceous and earlier oceans generally resulted in a greater fractionation of C isotopes and produced organic C having lighterδ13C values. Modern marine photosynthesis may be occurring under unusual geological conditions (higher oceanic primary production rates, lower) that limit dissolved CO2availability and minimize carbon isotope fractionation4.