Carbon Isotope Fluctuations in Cretaceous Pelagic Limestones: Potential Stratigraphic and Petroleum Exploration Tool
Carbon Isotope Fluctuations in Cretaceous Pelagic Limestones: Potential Stratigraphic and Petroleum Exploration Tool
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DOI：
10.1306/2f91892d-16ce-11d7-8645000102c1865d
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发表时间：
1980
期刊：
影响因子：
3.5
通讯作者：
P. Scholle;M. Arthur
中科院分区：
文献类型：
--
作者：
P. Scholle;M. Arthur
在环大西洋-西特提斯地区广泛分布的陆上剖面的白垩纪远洋石灰岩中，存在显著的短期碳同位素波动。在这项研究中，超过1000个紧密间隔的样本被分析。至少有7个主要的^dgr13C漂移可以在剖面之间相互关联。最重要的“重事件”发生在阿普提亚—阿尔比尼亚和塞诺曼尼亚—turonian边界附近，而“轻事件”发生在侏罗纪—白垩纪、阿尔比亚—塞诺曼尼亚、turonian—coniacian和白垩纪—第三纪边界附近。“事件”与阶段边界的关联以及地层剖面之间“事件”的一致性对比为独立于标准生物地层技术的时间-岩石对比提供了重要的新工具。这些碳同位素事件与阶段边界（动物和植物事件）、全球海平面上升变化和海洋“缺氧事件”的时间关联表明，碳同位素研究在解释古海洋环流变化方面可能有用。此外，碳同位素变化与缺氧事件的关联可能有助于评估深海和大陆边缘沉积物中有机物保存的精确时间和程度。因此，同位素研究可以帮助估计大部分未勘探的海洋盆地或沿大陆边缘的潜在碳氢化合物资源。
Significant short-term carbon isotope fluctuations are present in Cretaceous pelagic limestones from widely distributed onshore sections in the Circum-Atlantic-western Tethyan region. More than 1,000 closely spaced samples were analyzed during this study. At least seven major ^dgr13C excursions can be correlated from section to section. The most important "heavy events" occur near the Aptian-Albian and Cenomanian-Turonian boundaries, whereas "light events" are near the Jurassic-Cretaceous, Albian-Cenomanian, Turonian-Coniacian, and Cretaceous-Tertiary boundaries. The association of "events" with stage boundaries and the consistent correlation of "events" between stratigraphic sections provides a significant new tool for time-rock correlation independent of stan ard biostratigraphic techniques. The temporal association of these carbon isotope events with stage boundaries (faunal and floral events), global eustatic sea-level variations, and oceanic "anoxic events" demonstrates the potential usefulness of carbon isotope studies in interpreting variations in paleo-oceanic circulation. Furthermore, the association of carbon isotope variations with anoxic events is potentially useful for evaluation of the precise timing and the magnitude of preservation of organic matter in deep-sea and continental-margin sediments. Thus, isotopic studies may aid in estimating potential hydrocarbon resources in largely unexplored oceanic basins or along continental margins.