Sedimentary Characteristics And Tectonic Significance Of The Kulumudi Fomation Of Qiada Area, Western Junggar

This dissertation is object on the sedimentary stratum of Devonian Kulumudi Formation in Qiada Area of Western Junggar. Studying the features of strata in our researching area synthetically, including the field character, lithofacies, rock association, organic fossil, contact relationship between the stratum and tectonics environment, et al. Through the several years of field survey and general research, gained the achievement as follows:1.Kulumudi Formation in kuokehada Area of Western Junggar, which is a set of shore deposit-shawllow deposit pyroclastic rock and clastic rock combination。2.Many biology fossils are found in Kulumudi formation, such as Atrypa cf. Interrupta Grabau, Lptostrophia sp., Paraspirifer gigantean Su, Cryptonella? sp., Fistulipora sp., Syringaxon sp., Syringaxon eminence Cai, Neaxon curta (pocta), Planocoenitesi sp., Planocoenites cf.gradatus (Lecompte), Cladopora sp., Thamnopora cf. alta (Tchernychev), Temnophyllum sp., Zelophyllia sp., Lepfophleum rhombicum Dawson, Phacopidae et al. the ages of them is early Middle Devonian.3.The stratum aboved-mentioned unconformity on the Mayilashan Formation, conformable contact on the overlying Baerleike Formation.Combined with biological fossils and regional data, we regularize this stratigraphic is Kulumudi Formation, period is the Middle Devonian.4.According to rock assemblage, biology fossil, basic sequence and forming environment, we realize that sedimentary environment follow deep-shallow-deep changes. And first part are shallow sea environment, hydrodynamic is weaken. second to seventh part are littoral sea environment, hydrodynamic enhance.eighth section is shallow sea environment, hydrodynamic abate.5.The redefinition and contrast of Kulumudi Formation, which end our understanding confusion phenomenon, This conclusion provide important scientific basis for restore sedimentary environment in west Junggar.6.Kulumudi Formation is the main composition of volcanoclastic rock, show study area with strong crust activity. And this area lack sedimentary record of Early Devonian, indicate Caledon tectonic movement with collision orogenic role, whose performance is strong.