大龙口地区仓房沟群的沉积环境及其演化

SEDIMENTARY ENVIRONMENT AND ITS EVOLUTION OF CHANGFANGGOU GROUP IN DALONGKOU REGION

楼章华 赵霞飞 刘志刚 王瑶

Lou Zhanghua Zhao Xiafei Liu Zhigang Wang Yao

仓房沟群(P-T)发育于准噶尔盆地的东部,厚1000m士,由冲积扇、曲流河、低弯度河、网状河和湖泊相组成。沉积特征和变化反映了气候逐渐干旱、植物逐渐稀少和周期性活动的构造背景。气候和构造的变化导致沉积环境的演化,曲流河演化到低弯度河是由温暖、潮湿的气候和植物丰富的自然环境演化到炎热、半干旱的气候和极少或无植物环境的过程。随着物源区抬升,低弯度河网状化,发育楔状网状河相。

The Changfanggou Group(P-T),developed at the east part of Junggar is represented by some 1000m of elastic sediments which comprises fluvial-fan factes,meandering stream factes and low-sinuosity stream facies,braided stream factes and lacustrine fade.Sedimentary properties and the changes in fluvial styles reflect an increasing aridity and decreasing flora population under cyclic tectonic active condition during P-T period.The changes in paleoclimate and paleotectonics resulted in the variation of sedimentary environment.The variation from meandering stream to low-sinuosity stream was a process from warm and humid climate,luxuriant plants to hot and semiarid climate, nonvegetation enveronment.The low sinuosity streams become braid streams and wedge-shaped braid factes developed in the study area with the uplift of provenance.

10.11743/ogg19950104