CAJ | 학술논문

本文通过岩心观察、录测井及岩心粒度资料,对鄂尔多斯盆地麻黄山西区块北部中侏罗统延安组延一段的岩石组分、结构构造、粒度分布等特征进行分析,确定其沉积相类型.结果表明:延安组延一段属河流沉积体系,发育辫状河和曲流河两种沉积类型,主要包括河床和河漫两个亚相,可进一步识别出河床滞留、心滩、边滩、河漫滩、河漫沼泽、决口扇等微相.延一段延10油层组沉积时期,研究区以辫状河沉积为主,心滩发育,河道较宽,平面上摆动宽度为2~8km,主水流方向由西北至东南;延一段延9油层组沉积时期,受鄂尔多斯盆地湖水面整体抬升的影响,河道分布范围逐渐缩小,研究区以曲流河沉积为主,发育两条曲流河,平面上摆动宽度约2~4km,河道凸岸发育边滩沉积.
본문통과암심관찰、록측정급암심립도자료,대악이다사분지마황산서구괴북부중주라통연안조연일단적암석조분、결구구조、립도분포등특정진행분석,학정기침적상류형.결과표명:연안조연일단속하류침적체계,발육변상하화곡류하량충침적류형,주요포괄하상화하만량개아상,가진일보식별출하상체류、심탄、변탄、하만탄、하만소택、결구선등미상.연일단연10유층조침적시기,연구구이변상하침적위주,심탄발육,하도교관,평면상파동관도위2~8km,주수류방향유서북지동남;연일단연9유층조침적시기,수악이다사분지호수면정체태승적영향,하도분포범위축점축소,연구구이곡류하침적위주,발육량조곡류하,평면상파동관도약2~4km,하도철안발육변탄침적.
Abstract: The compositions, sedimentary structures, grain size distribution and sedimentary facies types are examined on the basis of cores, well logs and grain size data of the rocks from the 1st member of the Middle Jurassic Yanan Formation in western Mahuangshan, Ordos Basin. The 1st member of the Yanan Formation is built up of the fluvial sedimentary system in which the braided and meandering stream deposits are developed. Two sedimentary subfacies have been distinguished including the riverbed and overbank subfacies which may be subdivided into the riverbed lag, channel bar, point bar, overbank, backswamp and crevasse-splay microfacies. During the deposition of the Yan-10 oil measures, the 1st member of the Yanan Formation was occupied by the braided stream deposits with well-developed channel bars and wider channels. The palaeocurrents were oriented NW to SE. Influenced by the lake-level rising during the deposition of the Yan-9 oil measures, the study area was prevailed over by the meandering stream deposits with the point bar deposits.