摘要
在泥质沉积物颗粒分级的基础上,用显微镜检测、XRD和色谱分析等手段获取有机质和无机矿物的特征,探讨了二者间的相互关系以及有机质富集的差异性。沉积物偏粗粒级中主要富集的是颗粒有机质,有机碳含量高,C29色谱峰显著;偏细粒级中主要富集的是可溶有机质,有机碳和氯仿沥青A含量均高,C17色谱峰显著,呈现出有机质向粗和细两个端元富集的特点。粗粒级中无机矿物是化学性质稳定的长石和石英等碎屑颗粒,细粒级中是具有较强化学活性的粘土矿物。因此,在粗粒级中有机质是通过颗粒有机质与矿物颗粒相互共生而富集,在细粒级中有机质则是通过可溶有机质与粘土矿物相互结合形成复合体而富集。这反映了不同类型有机质富集机制的差异,会对有机质的保存和演化以及有机质生烃和碳循环过程产生影响,应引起高度重视。
The distribution of organic matter （OM） in sediments nism and interaction of organic matter with inorganic minerals in is heterogeneous. To study OM enrichment mechaargillaceous sediments, we employed size grading microscope, X-ray diffraction （XRD） and gas chromatography （GC） to obtain information on OM and minerals. It shows that OM may be enriched in both coarse and fine fractions. OM enriched in coarse fraction is mostly biogenic debris, which is characterised by large organic carbon （OC） contents and a marked C29 chromatographic peak; while OM enriched in fine fraction is mainly dissolved OM, which is characterised by large OC and chloroform bitumen ＂A＂ contents and a of clastic particles, such marked C17 chromatographic peak. Besides, coarse fraction as feldspar and quartz, and fine fraction is mainly comprised of sediments consists mainly of clay minerals, which are comparably vivacious. Our results indicate that in the coarse fraction, the OM enrichment is mainly caused by close association of biogenic debris with mineral grains; while in the fine fraction, the OM enrichment is mainly caused by interaction of dissolved OM with clay minerals to form organo-clay complexes. Different OM enrichment mechanisms have important influence on OM preservation, evolution, oil generation and carbon cycle, etc. , and should attract much attention.
出处
《高校地质学报》
CAS
CSCD
北大核心
2006年第2期234-241,共8页
Geological Journal of China Universities
基金
中石化科技部"沉积盆地成烃成藏基础理论研究"项目资助
关键词
泥质沉积物
有机质分布
有机-无机相互关系
富集差异性
argillaceous sediment
OM distribution
organic-inorganic interaction
enrichment difference
