CAJ | 학술논문

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.
탑리목분지화화북지태전니분기해상지층중엄범존재원우굉관조류적탄질박막화석,현미경하표현위균질적조대상경상체,저류경상체반사솔수매심정현규률성증고.통과부함저류경상체적상원고계청백구계하마령혈암(등효경질체반사솔0.66%)화탑중북사파상오도통니회암(등효경질체반사솔0.97%)여상응성숙도부식매공존적가수열해화간법열해모의실험,건립기원우굉관조류경상체반사솔여경질체반사솔적상관관계.대원우굉관조류경상체부집물적NMR화Py-GC-MS분석현시,굉관조류유궤질중존재취분류대분자,이분류화완기분류화합물정시경질체선구물목질소적전형열해산물.설명원우굉관조류적경상체무론시광성화형태환시화학성분화결구균정현출여경질체적상사성,원우굉관조류적경상체적반사솔가작위전니분기해상지층성숙도표척.
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 andC_1-C_3 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.