The Sedimentary Facies Classification And The Environment Evolution Of Penglai Group In Qixia

Penglai Group in the Qixia region lies in southeast margin of North China Plate, the binding site of jiaobei uplift and jiaolai depression.It belongs to jiaobei straturm region of Shandong eastern straturm region. It is jiaobei uplift crystalline basement of the sedimentary cover over the floor from Archaean era to Proterozoic era, and is a shallow metamorphic series and the highest position of all the jiaobei metamorphic series.Based on the opinion that neoproterozoic era of China can be divided into three parts, and the data of previous studies detailed analysis, Combined with measured field profile and experimental data, we explained the eventstratigphy and lithsostratigphy and demonstrated the stratigraphical age through the eventstratigphy correlation with adjacent area. Based on the analysis of metamorphism of penglai group, the original rocks were restored by the composition of the metamorphic rocks and the distribution patterns of the rare earth elements. According to the analysis of the characteristics of the original rock with others sedimentary characteristics, we identify the sedimentary facies of penglai group and study the sedimentary environment evolution.The results show that penglai group can be contrasted with tumen group in the west of Shandong through the eventstratigphy correlation, its age belongs to sinian period. It is a shallow metamorphic series, and suffered the low greenschist facies.The main original rocks are argillaceous rock, silty sandstone, quartz sandstone and carbonate rock. Two sedimentary facies and eight intrafacies can be identified in the penglai group,and sedimentary evolution can be divided into two stages including a complete cycles from progression and a transgression progress.