Some observations on the origins of large volumes of carbon dioxide accumulations in sedimentary basins
Some observations on the origins of large volumes of carbon dioxide accumulations in sedimentary basins
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DOI：
10.1016/s0264-8172(99)00047-1
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发表时间：
1999-10
影响因子：
4.2
通讯作者：
H. Wycherley;A. Fleet;H. Shaw
中科院分区：
文献类型：
--
作者：
H. Wycherley;A. Fleet;H. Shaw
在各种地质背景的沉积盆地中都发现了大量的二氧化碳(即高达90v/v%)，但它们的来源仍然是个谜。碳和稀有气体同位素分析的证据表明，对二氧化碳的起源有多种解释，包括地幔脱气、变质反应或岩浆作用。结合已发表的匈牙利帕尼尼亚盆地、澳大利亚库珀-伊罗曼加盆地和北海南维京地堑的已发表数据，讨论了沉积盆地中大量二氧化碳的形成。这些盆地有大量(即超过15v/v%)的重同位素二氧化碳(被认为是无机成因)，尽管它们在沉积充填方面有所不同，但都具有接近天然气聚集的主要构造特征。目前，现有的地球化学数据既不足以确定二氧化碳的具体来源(如地幔成因、碳酸盐变质作用)，也不足以解读来自两个或两个以上来源的混合二氧化碳：正在进行的研究，特别是那些涉及惰性气体分析的研究，应该能提供更全面的答案。
Large volumes of carbon dioxide (i.e. up to 90 v/v%) have been encountered in sedimentary basins from various geological settings but their origins remain enigmatic. Evidence from carbon and noble gas isotope analyses indicate a variety of interpretations for the origins of the CO2including mantle degassing, metamorphic reactions or magmatic processes. The formation of large accumulations of large volumes of CO2in sedimentary basins is discussed with specific reference to published data from the Pannonian Basin, Hungary; the Cooper–Eromanga Basin, Australia; and the South Viking Graben, North Sea. These basins have occurrences of large volumes (i.e. over 15 v/v%) of isotopically heavy carbon dioxide (thought to be of inorganic origin), and, although they differ somewhat in terms of sedimentary fill, all have major structural features close to the gas accumulations. The available geochemical data are currently neither sufficient to confirm the specific origin(s) of the CO2(e.g. mantle-derived, carbonate metamorphism) nor unscramble CO2mixed from two or more sources: ongoing studies, especially those involving noble gas analyses, should provide fuller answers.