新疆地质
新疆地質
신강지질
XINJIANG GEOLOGY
2014年
4期
530-534
,共5页
北大滩地区%侏罗系%石门沟组%构造作用%沉积环境%地质约束
北大灘地區%侏囉繫%石門溝組%構造作用%沉積環境%地質約束
북대탄지구%주라계%석문구조%구조작용%침적배경%지질약속
Beidatan area%Jurassic%Shimengou Formation%Tectonism%Sedimentary environment%Geological constraint
位于柴北缘东部北大滩地区的石门沟组为一套中侏罗统含煤地层,通过野外露头、钻井岩心及区域性地质资料对北大滩地区聚煤规律进行了研究。结果表明,煤层的发育和展布受构造作用和沉积环境的双重约束。受燕山运动I、II幕的影响,北大滩地区在中侏罗世接受沉积,经历了湖泊-扇三角洲两大沉积体系的改造。石门沟组沉积早期,北大滩地区为湖泊相沉积,滨湖沼泽成煤;石门沟组沉积晚期,研究区内发育两个大型的扇三角洲沉积体,扇三角州平原和扇三角州前缘成煤。石门沟组成煤期后,北大滩地区经燕山运动III幕、喜山运动及新构造运动的叠加,形成大规模的复式向斜构造。受逆冲断层影响,侏罗系整体抬升,使埋藏深度变浅,有利于煤层的勘探。
位于柴北緣東部北大灘地區的石門溝組為一套中侏囉統含煤地層,通過野外露頭、鑽井巖心及區域性地質資料對北大灘地區聚煤規律進行瞭研究。結果錶明,煤層的髮育和展佈受構造作用和沉積環境的雙重約束。受燕山運動I、II幕的影響,北大灘地區在中侏囉世接受沉積,經歷瞭湖泊-扇三角洲兩大沉積體繫的改造。石門溝組沉積早期,北大灘地區為湖泊相沉積,濱湖沼澤成煤;石門溝組沉積晚期,研究區內髮育兩箇大型的扇三角洲沉積體,扇三角州平原和扇三角州前緣成煤。石門溝組成煤期後,北大灘地區經燕山運動III幕、喜山運動及新構造運動的疊加,形成大規模的複式嚮斜構造。受逆遲斷層影響,侏囉繫整體抬升,使埋藏深度變淺,有利于煤層的勘探。
위우시북연동부북대탄지구적석문구조위일투중주라통함매지층,통과야외로두、찬정암심급구역성지질자료대북대탄지구취매규률진행료연구。결과표명,매층적발육화전포수구조작용화침적배경적쌍중약속。수연산운동I、II막적영향,북대탄지구재중주라세접수침적,경력료호박-선삼각주량대침적체계적개조。석문구조침적조기,북대탄지구위호박상침적,빈호소택성매;석문구조침적만기,연구구내발육량개대형적선삼각주침적체,선삼각주평원화선삼각주전연성매。석문구조성매기후,북대탄지구경연산운동III막、희산운동급신구조운동적첩가,형성대규모적복식향사구조。수역충단층영향,주라계정체태승,사매장심도변천,유리우매층적감탐。
Shimengou Formation is a set of middle Jurassic coal-bearing strata in the east of Qaidam northern margin of Beidatan area.This paper analysed coal accumulation rule of Shimengou Formation by the field outcrop,core drilling and regional geological data.The result shows that spreading and growth of coal bed constrainted by tectonism and sedi-mentary environment.With affection of I andⅡcurtain of Yanshan movement,Beidatan area accepted deposition in Mid-dle Jurassic and experienced reform by lake-fan delta sedimentary system.In the early of Shimengou deposition,Beidatan area had lake facies deposition with coal forming in lakeshore swamp;Two large fan delta sedimentary bodies develop-ment in the study area in the late of Shimengou deposition and coal forming in Fan delta plain and front.Beidatan area ex-perienced movement stacking such as Ⅲ curtain of Yanshan movement,Himalayan movement and Neotectonic move-ment with multiple syncline formed in Beidatan area at last.With affection of thrust faults,all Jurassic layers in Beidatan area uplifted as a whole with lower buried depth,which are benefit for exploration.