大兴安岭北部上古生界极低级变质温度——来自碳质物拉曼光谱的证据  

Very Low Grade Metamorphic Temperatures of the Upper Paleozoic Strata in Northern Daxing'anling Area,NE China:Evidence from Raman Spectrum Studies of Carbonaceous Materials

作　　者：胡大千[1] 王岩泉[1] 沙茜[1] 王春光[1] 陈旭[1] 马瑞[1] 

机构地区：[1]吉林大学地球科学学院,长春130061

出　　处：《吉林大学学报（地球科学版）》2015年第1期188-197,共10页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(41172039;41372042);中石化项目(GO800-06)

摘　　要：使用Renishaw System-1000型激光拉曼光谱仪,研究了大兴安岭北部上古生界泥质岩石碳质物的拉曼光谱特征及其对形成温度的表征,探讨了拉曼光谱参数与镜质体反射率（Ro）的关系。研究表明：研究区上古生界泥质岩石碳质物不具有石墨的拉曼光谱谱带吸收峰,揭示了地层的变质程度未达到低绿片岩相。利用此次经过完善建立的拉曼光谱地质温度计,对大兴安岭北部上古生界泥质岩石变质温度的估算结果主要为270~320℃,表明研究区上古生界遭受了极低级变质作用,变质程度属近变质带。依据碳质物拉曼光谱参数与镜质体反射率的相互关系,估算研究区有机质成熟度的Ro值主要分布为3.03%~4.23%,与实测Ro值吻合,表明有机质演化处于过成熟阶段,泥质岩石具有生烃的能力,部分层位可能具有形成油气资源的潜力。Using the Renishaw System-1000 laser Raman spectrometer,authors have studied the laser Raman spectrum characteristics of the carbonaceous materials in pelitic rocks outcropped in northern Daxing＇anling area and its indication to the metamorphic temperature.The relationship between the various parameters of the Raman spectrum and the vitrinite reflectance（Ro）of the carbonaceous materials is also discussed.The study shows that the carbonaceous material of Upper Paleozoic pelitic rock has not the Raman spectrum absorption peak of graphite,revealing its metamorphic grade below the low-greenschist facies.Using Raman spectroscopy constructed and proposed by Barkeret al.（1986）and by Rahl et al.（2005）,the metamorphic temperature of Upper Paleozoic pelitic rock in the studied area is estimated at 270℃ to 320℃,indicating the Paleozoic strata of the area have merely undergone very low grade metamorphism and metamorphic grade belongs to anchizone.Based on the relationship between the laser Raman spectrometer of carbonaceous materials and the vitrinite reflectance（Ro）proposed by Wang Y,et al.（2002）,the Rovalues（maturity of organic materials）of pelitic rocks are estimated to be from 3.03% to 4.23%,consistent with the measured values,showing that the evolution of organic matter of the area is at the over-mature stage,and the pelitic rocks in the area are capable to be generate the hydrocarbon generation and part of the them may have the potential for oil and gas resources.

关 键 词：大兴安岭北部 上古生界泥质岩石 碳质物拉曼光谱 镜质体反射率 地质温度计 极低级变质作用 

分 类 号：P574.1[天文地球—矿物学]