Black shales
Black shales
复制标题
DOI：
10.1144/gsjgs.137.2.0123
复制
发表时间：
1980-03
影响因子：
2.7
通讯作者：
W. Kohlberger
中科院分区：
文献类型：
--
作者：
W. Kohlberger
“黑色页岩”是一个古老的术语，指富含有机质的泥质岩石。这类矿床的沉积环境特征长期以来一直引起地质学家的兴趣，特别是现实模式的适用范围。近几年来，人们对黑色页岩的兴趣重新高涨，主要是因为人们普遍认识到黑色页岩可能是重要的石油源岩，以及在深海中发现了富含有机物的白垩纪沉积物。鉴于这种迅速增长的兴趣，需要更精确的定义和分类已成为当务之急（见斯皮尔斯的论文），尤其是因为“黑色页岩”现在正在进入Franglais的领域。我心目中的那种岩石既不需要是黑色的，也不需要是泥质的，尽管它们通常都是黑色的。在我看来，最典型的岩性特征是平行于层理排列的有机质薄层，它是岩石明显易裂的原因，这种岩石可能风化成所谓的纸页岩。有机质的含量很少超过百分之几;当它相当高时，岩石可以在蒸馏时产生石油，因此可以被描述为油页岩。无结构和化学惰性的干酪根占主导地位，但也存在陆地来源的孢子、花粉和木质物质以及非钙质微型浮游生物（例如甲藻）的不同混合物。现实主义的类比表明，厚度约为20-30 µ m的精细韵律干酪根-粘土纹层是季节性产生的纹层，因此可以用来估计沉积速率。主要无机成分
‘Black shales’ is an old term for argillaceous rocks rich in organic matter. The characteristics of the depositional environment of such deposits have long intrigued geologists, particularly the extent to which actualistic models can be applied. The revived interest in the last few years stems principally from the wide-spread recognition that black shales may be important source rocks for petroleum, and from the discovery of organic-rich Cretaceous deposits in the deep ocean. In view of this burgeoning interest, the need for more precise definition and classification has become imperative (see the paper by Spears), the more so because ‘black shales’ is now entering the realm of Franglais. The kind of rocks I have in mind need be neither black nor shaly, although they usually are. In my opinion the most characteristic lithological feature is laminae of organic matter arranged parallel to the bedding and responsible for the pronounced fissility of the rocks, which may weather to so-called paper shales. The content of organic matter rarely exceeds a few percent; when it is considerably higher the rock may yield petroleum upon distillation and hence can be described as oil shale. Structureless and chemically inert kerogen dominates, but there is a variable admixture of terrestrially-derived spores, pollen and woody matter together with non-calcareous microplankton such as dinoflagellates. Actualistic analogues suggest that the fine rhythmic kerogen-clay laminae, of the order of 20–30 µ m in thickness, are seasonally-produced varves, which can therefore be used to estimate rates of sedimentation. The dominant inorganic constituents