Haracteristics Of Mesozoic Lithofacies Palaeography Of Big Yalu Jiang Basin In Southeast Jilin

For a comprehensive study Characteristics of Mesozoic lithofacies palaeographyof Yalu Jiang Basin in southeast Jilin,this paper has collected26coalfield drillingdata,and measured19sections, lots of first-hand field information has been collectedin detail.During the Triassic-Cretaceous period, experienced the later stage of Indosinianorogeny and Yanshan movement, since the Indosinian orogeny, the seawater retreated,the research area as a whole rise to land.Due to the Pacific plate subducted of theEurasian plate, and produced the NNE-trending of left-lateral strike-slip faults of theYalu jiang and the Dunhua-Mishan，which are branch of the northern Tan-Lufault,Yalu Jiang basin effected by the two groups of fracture, on the basis of originalold base, the study area began orogenic movement, deposited10of smallintermountain depressions(fault) basins in Yalu river basin.Strike-slip fault is the main factor causing basin formation and sedimentfilling,the spread direction is nearly NNE，speculate that the regional tectonic madesedimentary basin and subsidence center move to NNE, source and river systemsalong the basin axial and vertical these faults distribution.Yalu jiang basin Mesozoic development of four sets of coal measures strata anddark mudstone,so the Mesozoic is divided into four sedimentary sequences,Mesozoicalso happened four stage relatively intense volcanic eruption activities, and formed aset of Calc-alkaline series combination of volcanic and volcaniclastic rocks,whichMainly to neutral-acid rock. Volcanic eruptions included Changbai period,Guosongperiod,Linzitou period,Sankeyushu period, formed in orogenic belt environment,which is orogenic belt production, from west to east, volcanic activity raised in turnMake full use of previous research results, on the basis of the sedimentary facies, according to the lithology combination，sedimentary fabric，depositional evolutionsequence，consider the Yalu jiang basin the Mesozoic is the continental sedimentsenvironment,and is developed with alluvial, fan-delta delta, fluvial, lacustrine faciesand volcanic formation,detailed analysis of the various sedimentary faciescharacteristics and spatial, space distribution,and contrast sedimentary facies profile,At the same time, homologous depositional model is erected.This thesis use group formapping units,use the advantage of fices in graphic method, compiled7lithofaciespaleogeography map,discussed different period of the sedimentary system planardistribution characteristics and configuration relationship,reveal different periodlithofacies palaeogeography pattern and evolution characteristics.