碳酸盐岩与泥(页)岩有机质演化的差异及成因探讨

DIFFERENCE IN THE EVOLUTION OF ORGANIC MATTERS BETWEEN CARBONATES AND MUDSTONES (SHALES) AND ITS ORIGIN

本文通过对浙江、湖北、贵州和泌阳等地不同岩类样品的岩石热解、液相色谱和干酪根热解色谱分析,阐述了碳酸盐岩与泥(页)岩有机质演化的差异及成因问题。结果表明,在相同的成生条件下,泥(页)岩中有机质的演化程度较碳酸盐岩高,其原因可能主要与粘土矿物对有机反应的催化作用有关。泥(页)岩中存在大量的蒙脱石和伊利石等粘土矿物,使岩石中的有机质在经受热力作用影响的同时,还受到粘土矿物催化作用的影响,因此其演化程度高于没有或只有少量粘土矿物的碳酸盐岩。

This paper presents the analytical data on Rock-Eval,liquid chromatogr- aphy and pyrolytical chromatography of some kinds of rock sampales from Zhejiang,Hubei,Guizhou and Biyang,and shows the difference and genesis in the evolution of organic matters between carbonates and mudstones (sha- les).It has been concluded that the maturity of organic matters in mudstones (shales) is higher than those in carbonates under the same conditions of depo- sitional setting and thermal stress,which is resulted mainly from the cataly- sis of clay minerals to the organic chemical reactions.There are a lot of clay minerals,such as montmorillonite and illite in the mudstones (shales).Thus, besides being subjected to the thermodynamic effect,the organic matters in the mudstones (shales)are also subjected to the catalytic action of clay minerals.Therefore,the organic matters in the mudsiones (shales) are in a maturity stage higher than those in the carbonates in which no or very few clay minerals are observed.