西准噶尔晚石炭世哈拉阿拉特山组烃源岩发育沉积环境与有机质富集因素分析  

Sedimentary environment and organic carbon enrichment factors of the Late Carboniferous Hala＇alat hydrocarbon source rocks in West Junggar

作　　者：陶辉飞[1] 邱振[2,3] 吉鸿杰[1] 邱军利[1] 

机构地区：[1]甘肃省油气资源研究重点实验室、中国科学院油气资源研究重点实验室、中国科学院西北生态环境资源研究院,兰州730000 [2]中国石油勘探开发研究院,北京100083 [3]中国石油勘探开发研究院廊坊分院,河北廊坊065007

出　　处：《地质科学》2017年第1期79-92,共14页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国科学院“西部之光”西部博士项目（编号：2013）、国家自然科学基金青年基金项目（编号：41502110）和中国科学院青年创新促进会项目（编号：2016068）资助.

摘　　要：准噶尔盆地西北缘哈拉阿拉特山地区发育一套晚石炭世哈拉阿拉特山组灰黑色泥岩层系，是该地区石炭系油气藏的主要烃源岩之一，但到目前为止，对该套烃源岩发育的沉积环境和有机质富集因素的认识尚不清楚。本文基于西准噶尔哈拉阿拉特山地区晚石炭世哈拉阿拉特山组乌和公路剖面，进行了详细的沉积学和岩石学研究，系统采集了17件新鲜泥岩样品，并开展了有机碳含量、主量元素和微量元素实验分析。通过综合分析野外调查结果和室内实验数据，得到如下几点认识：1）哈拉阿拉特山组泥岩发育在深海-半深海的沉积环境中，受浊流沉积频发的影响，底层水体一直处于富氧一缺氧的动荡变化过程之中；2）低V／Cr和U／Th比值，以及低v和u元素含量，指示了泥岩总体上形成于偏氧化的沉积环境；3）高的P和Ni元素含量，反映了当时水体具有较高的古生产力；4）在较高古生产力背景下，哈拉阿拉特山组泥岩有机质丰度（TOC平均为0．49％）偏低，原因是偏氧化的保存条件。因此，可以认为哈拉阿拉特山组泥岩有机质质富集主要受控于沉积水体的保存（氧化还原）条件。A set of Late Carboniferous Hala＇alat gray dark mudstones distribute in the Hala＇alat Mountains area Northwest Junggar Basin. These mudstones are one of the major hydrocarbon source rocks of the Carboniferous oil field in this area. However, to date, the depositional environment and organic matter enrichment factors are still unclear. On the basis of detailed study the sedimentology and petrology of the Wu-He Road section of the Late Carboniferous Hala＇alat Formation in the Hala＇alat Moutains, Northwest Junggar, seventeen fresh mudstone samples were collected, and then the mudstone samples were carried on the experiments of total organic carbon content, major elements and trace elements. Several viewpoints are concluded by the comprehensive analysis the field investigation results and experiment data. 1） The Hala＇alat mudstones were deposited in a semi-deep to deep sea environment, and influenced by frequency turbidity flow, which caused the bottom water in a turbulent environment from oxic to suboxic; 2） low values of V/Cr, U/Th, V and U, show that the mudstones deposited in a more oxidation tendency environment; 3） high contents of P and Ni reflect a relatively high paleo-productivity of the marine ; 4） on the background of relatively high paleo-productivity, but the total organic carbon content of the Hala＇alat mudstones are relatively low （TOC avg. 0.49%）, reflecting the oxidation environment is the major controlling factors. Therefore, the redox conditions are the primary controlling factors of the Hala＇alat mudstones＇ organic carbon enrichment.

关 键 词：西准噶 晚石炭 古生产 沉积环 微量元素 

分 类 号：P534.4[天文地球—古生物学与地层学] P539.4[天文地球—地质学]