Study Of Sedimentary Environment Of Jiangbei Conglomerate

Global changes will bring advantageous or disadvantageous to influence human beings. Man must understand global changes and we can take proper countermeasures. Studying global changes is a hot spot now . Quaternary ( also named Human Period ) especially late Quaternary was close to human beings origin and development .It is the most valuable information base to study bypast global changes and studying its environment evolvement is very important for human beings . Along with building Three Gorges Dam and exploiting the reservoir area, It is very important to strengthen studying environment evolvement of middle and upper reaches of Yangtse River. Jiangbei conglomerate which wide-spreads in lower terrace of Quaternary sediment along the river in Sichuan Basin can reflect paleoenvironment information including paleoflood, paleoclimate, paleovegetation, etc, and is an un-come-at-able carrier of studying paleoenvironment evolvement of local area during last stage of late Pleistocene and Holocene.Jiangbei conglomerate is a kind of allothigenic supergene cemented rock that wide-spreads in lower terrace of Quaternary sediment along the river in Sichuan Basin and it's adjacent area, and consists of conglomerate and sandstone. Hence, it is also named Jiangbei conglomerate and sandstone rock. Jiangbei conglomerate has its own characteristic different from other river sediment, namely it cemented to solid rock on earth's surface and only spread on the lower terrace. Scholars are interested in its diagenetic reason and speculate that it might diagenism in special climate . But there are many different opinions about the diagenesis climate. Liu Xingshi thought that it diagenismed in dry-hot climate in Holocene Epoch .But Yang Dayuan thought it diagenismed in dry-cold climate in late Pleistocene. Because the matrix of Jiangbei conglomerate is very complex, it is very difficult to choose the carrier of dating exactly and paleoenvironment analysis . The diagensis reason isn't clear now. The author bases on the past investigation and uses new technology and new method which are used in studying paleoenvironment to study diagentic age and diagentic environment.We draw a conclusion that the sedimental chron of Jiangbei conglomerate is between 10000 and 40000 years . The upper of Jiangbei conglomerate along Yangts River was...