The Study Of Volcanic Rocks Of Paleoproterozoic Nansi Formation In The Area Of Ceyu-lincheng Of The Heibei Province

The study area is located in the southwest of Hebei Province,the southern section of the Taihang Mountains in the East,tectonically belonging to the North China Craton of Central Orogenic Belt in the southern part of the Zanhuang massif in the Midwest.In the area of the Paleoproterozoic Nan si Formation is better,volcano rocks are widely distributed.This paper conducted a field survey and relevant section measurement of volcano rock temple group,and combined with the main elements of rock,geochemistry and trace elements of the system,analyzed and summarized the characteristics of the Paleoproterozoic volcano rock strata and rock temple group characteristics,volcano rock cycle characteristics,tectonic characteristics and petrogenesis.Volcano rock group of Paleoproterozoic Nan si Formation in this district are clastic-basaltic andesite and andesite rocks,only a small part of the basaltic volcano rock;rock according to the analysis of chemical characteristics of volcano rock indicate that Nan si Formation volcano rocks in this area generally belongs to a quasi aluminum high K calc alkaline basaltic andesite volcano rock series;trace elements do not show the compatibility of large ion lithophile elements K,Ba,Rb,Th and light rare earth elements La,Nd,Sm Zr,Nb,P concentration,Sr,high field strength elements relatively depleted,the volcano rock characteristics and convergence characteristics of rock combination environment is similar.According to the research ideas of cyclic stratigraphy,the volcano rock group Nan si Temple as a super cycle,the Nan si supercycle supercycle.Nan si can also be divided into 3 cycles,and 9 rhythm types.From volcano more eruption facies-eruption facies-overflow facies interactive overflow facies,reflects the intensity of volcano activities from the strong strong weak evolution.A comprehensive study of volcano rock of the regional geological background,deformationcharacteri tics,rockassemblage,geochemistry,auxiliarytectonicdiscriminati on diagrams,presumably formed in the subduction,arc tectonic setting of active continental margin in the development of many times,at the same time that the Nan si Formation basaltic andesite and andesite rocks is a set product of magma crystallization separation of the causes.