Research On Sedimentary And Geochemistry Of The Black Rock Series Of Cambrian Niutitang Formation In Nayong Area Of Guizhou Province

The research of black rock series with important scientific significance and economic value,is one of the hot topic in the forefront area of geology.The paper studies the sedimentology and geochemistry of the black rock series of Cambrian Niutitang Formation in Nayong area of Guizhou province.Based on the element geochemistry and organic geochemistry,we discussed the formation background of the black rock series, the type/input/ maturity/ abundance of the organic matter of the black rock series. The main conclusions are as following:(1) The black rock series of Niutitang Formation which consist of phosphate rock, crystalline limestone and carbonaceous shales, is formed in a low-energy and anaerobic platform edge environment. Because of the Yangtze ingression, there were a lot of bacterium and alga,provided abundant organic matter for the sedimentary of the black rock series.(2) Based on the research of the characteristic of the element geochemistry, we can draw the conclusion that the black rock series deposited in a anaerobic and reducing environment in which the organic matter is preserved easily.(3) Analyzing on the TOC of the sample,it indicates that the black rock series is of high TOC,with abundant organic matter.Contrasing the standard,we think the black rock series are good source rocks.(4) We extracted plenty of normal paraffin hydrocarbons, isoprenoid, terpenoid and steride from the samples of the black rock series.According to the research of parameters of biomarkers, we concluded that the organic matter originated from homoneneae,with good type. The black rock series deposited in a anaerobic and reducing environment in which the organic matter is preserved easily .And the organic matter is of high mature.(5) The form of the black rock series of Niutitang Formation is close to the anoxic affair in Early Cambrian. Because of the Yangtze ingression, there were a lot of bacterium and alga,provided abundant organic matter for the sedimentary of the black rock series.The organic matter of the black rock series is of good type and high mature.we concluded that the black rock series is good source rocks by researching the abundance/type/mature.