吐哈盆地草南1井中侏罗统物源方向综合判识及其研究意义  

A Comprehensive Judgement of the Source Direction of the Middle Jurassic of Chaonan 1 Well in the Tuha Basin and Its Research Significiance

作　　者：张晓宝[1] 何海清[1] 陈国俊[1] 

机构地区：[1]中国科学院兰州地质研究所

出　　处：《沉积学报》1997年第4期109-114,共6页Acta Sedimentologica Sinica

摘　　要：利用物源方向综合判识方法，通过吐哈盆地草南１井中侏罗统与物源区岩性特征以及草南１井与邻井地层厚度、岩石学特征和沉积相时空分布等方面的对比研究，认为其物源应来自于盆地南部的觉罗塔格山。这一研究成果对于完善沉积盆地物源方向判识方法。The source direction of the Middle Jurasic of Chaonan 1 Well in Tuha Basin was comprehensively judged through a comparative research on its lithologic characteristics of source areas and of its stratum thickness,and special distrilution of sedimentary facies of adjcent wells.The lithological difference of the north and south boundary mountains in Tuha Basin is clear,i.e,the southern Jueluotage Mt.is predorminated by acidic igneous rocks while the northern Bogeda Mt.by intermediate to basic rocks.The Clarke values of petrogenic elements,K,Ca,Mg,ferric family elements,Fe,Ni,Fe,rare earth elements,Sr,Ga,Rb,Ba of the Middle Jurassic mudstones of the Chaonan 1 Well were close to those of acidic igneous rocks.The two heavy mineral associations,rich in zircon and magnetite,respectively, basicatly represent ed those of acidic igneous rocks.The content of quartz in sandstones was over 20%,the microcline and orthoclase were high while the anothesite low,and the volcanic debris were mainly intermediate acidic ones,which are closely related with acidic igneous rocks.It coued initally be concluded from the above that the clasts of Chaonan 1 Well were derived from the southern Jueluotage Mt.From Yue 1 Well,sourthern to Chaonan 1 Well,to Xiaochao 1 Well,northern to Chaonan 1 Well,the thickness of sandstones became thin,the size smaller,and the physical properties worse.The thickness of mudstones got thicker,the color darker,the content of sands less,the content of organic matter higher and the type of organic matter better.Because the content of clay minerals,especially kaolinite,inceased and the mudstone thickened,the seal conditions were better.The above research result is of great significance in perfecting the judgement method of source direction of sedimentary basins,predicting the distribution of the most favorable reservoir bodies and source reservoir caprock associations and guiding the exploration of oils and gases.

关 键 词：物源方向 中侏罗统 盆地 油气勘探 草南构造 

分 类 号：P618.130.2[天文地球—矿床学] P618.130.8[天文地球—地质学]