Characteristic And Sedimentary Environments Of The Cambrian Oncolites In Shandong Province, China

In recent years,the Microbialite is always the study hotspot of Precambrian that its research is more, but the relatively less of the Cambrian research, Especially the oncolite is less, so the study of the oncolite research is still lack of systematic and integrity, there is no definite answer in many hot problem, mainly including the overall causes of the oncolite, the sedimentary environment analysis of the oncolite, the classification and formation and formation of microbes of the oncolite etc,so the research of the oncolite has extremely high theoretical value.Through to the analyze and research at the output oncolite layer of the Cambrian Mantou formation and Zhangxia formation at Luxi 22 areas,This article combine the field observations of description and indoor test analysis,such as backbone profiles are large scale measured (1:10 or 1:50), the oncolite output analysis at Luxi region mainly include name, core, lamina, type and so on, and the detailed classification, The core is divided into biological core, clastic core, gravel crumbs within the body core and a few other types of core of four;We divide the lamina into 10 types,which are dark mud crystal lamina, dark girvianella plexiform mixed and disorderly grow lamina, dark girvianella bar ribbon grow lamina, dark girvianella clot lamina, dark micrite clot lamina, bright color girvianella strip grow lamina, dark contain mineral lamina, light crystal calcite lamina, light crystal clastic lamina, calcite within light girvianella mixed and disorderly grow lamina etc.Through the microscopic observation, according to shape classification, the type of the oncolite are divided into the spherical oncolite, ellipsoid oncolite and ginger massive oncolite, According to the core position and the components,the oncolite will be divided into center oncolite, eccentric oncolite, simple oncolite and complex oncolite, According to the core layer thickness with grain shape stone,the oncolite will be divided into nuclear normal oncolite and thin skin oncolite, According to grain layer number,the oncolite will be divided into the single laminar oncolite and more wrinkles layer oncolite.The wild macro description of the oncolite types mainly includes Oncolite limestone, Bioclastic oncolite limestone,Oolitic oncolite limestone, Bioclastic oncolite qualitative limestone, oolitic qualitative oncolite limestone, Bioclastic and oolitic qualitative oncolite limestone, Oncolite bioclastic limestone,Oncolite oolitic limestone,Oncolite oolitic bioclastic limestone,Oncolite bioclastic oolitic limestone totaling ten kinds of oncolite sorting.Through a variety of research method in combination, the author divide the oncolite formation process into Core forming stages, Profiling formation stage, Sedimentary diagenetic stage, and divide 10 type of the oncolite microfacies;and analyzes the sedimentary environment of the oncolite at Luxi block, which is mainly for tidal-flat beach facies lagoon phase of tidal band and high tide low sedimentary environment, and establish two kinds of sedimentary environment of the corresponding sedimentary course of the oncolite. The detailed research of north China region of the Cambrian oncolite is good for the in-depth study of solid scientific basis, which is important.at the theoretical and practical application process.