Analysis Of Sedimentary Facies And Environment Of Huashan Group In The South Of Mudanjiang Area Heilongjiang Province

This thesis investigates the sedimentary facies and sedimentary environment of cretaceous Huashan Group Hailang formation and Houshigou formation which locate in the coal bearing in Hailang,Muling,and Dongning area of Mudanjiang Heilongjiang Province,aim to recover the lithofacies paleographly of late early cretaceous and early late cretaceous.The main progresses are as follows:1.In the Houshigou formation of lower cretaceous,the lower part is conglomerate with sandstone,the middle part is Siltstone and Mudstone with Sandstone,the upper part is mudstone and siltstone.In the gonghe area of the Muling county,the southeast of the research area,there is gravel-bearing sandstone in the Houshigou formation.The Hailang formation of the upper cretaceous is comprised of medium-coarse-grained feldspar sandstone,medium-fine-grained feldspar sandstone,silty mudstone,medium coarse conglomerate,fine sandstone,conglomerate and so on.2.In the Shihougou formation of the research area,conglomerate of the lower part is the result of the alluvial apron and fluvial facies.The iron red conglomerate in this part represents the arid and hot oxidation environment.The mud deposit in the upper part represents the fluvial and lake environment.The lower part of Hailang formation is mainly the fluvial facies sedimentation,the upper part represents the lacustrine deposit.3.In space,the late early cretaceous of the research area spreads along the northeast direction of Muling and Ningan,the alluvial fan evolved into fluvial facies,along the southeast direction,the alluvial fan evolved into lacustrine deposit,and the depocenter is based in the Wenge Village of Muling County.In the early late cretaceous,it evolved into fluvial conglomerate in the Qinghe area of Muling County,the center of sedimentary basin locates in Ningan city and the southeast area of the city,the whole basin is NE-trending.In the early early cretaceous,the lake basin in the wenge village atrophies to disappearance,which reflects the strong uplift of the southeast part and the sink of the Ningan area.