Thermal maturation as revealed by micro-Raman spectroscopy of mineral-organic aggregation (MOA) in marine shales with high and over maturities

作者：Xianming XIAO,Qin ZHOU,Peng CHENG,Jian SUN,Dehan LIU,Hui TIAN

摘要：Laser Raman spectroscopy of organic matter in coals and sedimentary rocks has been increasingly investigated to assess thermal maturity.Pure organic matter such as vitrinite and solid bitumen,as well as isolated kerogen are definitely selected for this purpose,but there has been no systematic report on the Raman spectral parameters directly based on mineral-organic aggregations(MOA)in shales.In this paper,the Raman spectral characteristics and parameters of MOA in two sets of marine shale samples from southern China with either different TOC contents(TOC=0.10–4.59%)or different maturities(BRo=1.71–4.57%)were investigated.It was found that the Raman technique is very sensitive to the organic matter in MOA.As the TOC content of the shales reaches about 0.60%,perfect Raman spectra with D and G bands derived from organic matter in MOAwere obtained,and the Raman parameters of MOA are in good agreement with those of its associated solid bitumen,and can indicate the thermal maturity just like those of solid bitumen.Using the Raman parameters of MOA is a potential alternative way to estimate maturity levels of high and over mature shales,especially those lower Paleozoic and Precambrian shales that lack macerals suitable for reflectance or Raman measurements.

发文机构：School of Energy Resources State Key Laboratory of Organic Geochemistry

关键词：MarineshaleMineral-organicaggregation(MOA)SolidbitumenRamanparameterMaturity

分类号： P618.13[天文地球—矿床学]