源于宏观藻类的镜状体反射率——前泥盆纪海相地层成熟度标尺  

Reflectance of macroalgae-derived vitrinite-like macerals:An organic maturity indicator for pre-Devonian marine strata

作　　者：王飞宇[1] 陈敬轶[1] 高岗[1] 孙永革[2] 彭平安[2] 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室 [2]中国科学院广州地球化学所有机地球化学国家重点实验室

出　　处：《石油勘探与开发》2010年第2期250-256,共7页Petroleum Exploration and Development

基　　金：国家自然科学基金项目(40772087;49972041);有机地球化学国家重点实验室项目(OGL-9906)

摘　　要：塔里木盆地和华北地台前泥盆纪海相地层中广泛存在源于宏观藻类的炭质薄膜化石,显微镜下表现为均质的条带状镜状体,这类镜状体反射率随埋深呈现规律性增高。通过富含这类镜状体的上元古界青白口系下马岭页岩(等效镜质体反射率0.66%)和塔中北斜坡上奥陶统泥灰岩(等效镜质体反射率0.97%)与相应成熟度腐殖煤共存的加水热解和干法热解模拟实验,建立起源于宏观藻类镜状体反射率与镜质体反射率的相关关系。对源于宏观藻类镜状体富集物的NMR和Py-GC-MS分析显示,宏观藻类有机质中存在聚酚类大分子,而酚类和烷基酚类化合物正是镜质体先驱物木质素的典型热解产物,说明源于宏观藻类的镜状体无论是光性和形态还是化学成分和结构均呈现出与镜质体的相似性,源于宏观藻类的镜状体的反射率可作为前泥盆纪海相地层成熟度标尺。Carbonaceous film fossils derived from macroalgae exist widely in pre-Devonian strata in the Tarim Basin and the North China Platform,and they are homogeneous strip-shaped vitrinite-like macerals under microscopic scale.The reflectance of vitrinite-like macerals increases with the burial depth regularly.The reflectance relationship of vitrinite and vitrinite-like macerals has been established through hydrous and nonhydrous pyrolysis experiments with co-existed Neoproterozoic Xiamaling shale（vitrinite reflectance equivalent of 0.66%） from North China Platform,Upper Ordovician marls（vitrinite reflectance equivalent of 0.97%） from the north slope of Tazhong Uplift in the Tarim Basin,and corresponding maturity humic coals.The NMR and Py-GC-MS analyses of the vitrinite-like maceral concentrates indicated that,polyphenol exists in organic matter of Macroalgae,and its pyrolysis products are dominated primarily by phenols and C1-C3 short chain alkylated phenols.These components are typical pyrolysate of lignin of the vitrinite precursors.Such results validate the similarities between vitrinite-like macerals derived from Macroalgae and vitrinite in morphology,optical properties and chemical composition and structure.Therefore,the reflectance of macroalgae-derived vitrinite-like macerals can be used as organic maturity indicator for the pre-Devonian marine strata

关 键 词：镜状体 宏观藻类 化学结构 有机成熟度 海相烃源岩 

分 类 号：TE122.1[石油与天然气工程—油气勘探]