The Evaluate Of The Source Rocks Of Cambrian Niutitang Formation In Songlin, Zunyi Area Of Guizhou Province

After the exploration and research, the source rocks of lower Cambrian Niutitang formation has caused much attention . A few scholars judged that the source rocks of lower Cambrian Niutitang formation get a high organic matter abundance , belong to good source rocks, they also judged that its hydrocarbon resources are rich, it will be an important area to be developed in the near future. The research of hydrocarbon resources in south China is one of the hot topic in the forefront area of geology . The paper mainly studies the sedimentology and geochemistry of the source rocks of lower Cambrian Niutitang Formation in Songlin Zunyi area of Guizhou province. Based on the element geochemistry, organic geochemistry and organic petrology , we discussed the formation background of the source rocks, the type/input/ maturity/ abundance/hydrocarbon bearing ability of the organic matter of the source rocks. The main conclusions are as following:(1)The rock series of Niutitang Formation which consist of phosphate rock, crystalline limestone,carbonaceous shales and crystalline limestone. phosphate rock distribute are not steady ,and it is thin of the south of anticline in zunyi cove and it is not discover in somewhere. Carbon shale distribute are continuously and thickness is fluctuate. The Ni-Mo ore in mudstone and shale out put thinly, the thickness distribution is continuous and steady. There are phosphate nodules in certain position. The rock series below the mine formed in the continental shelf environment, and those above the mine formed in the deep continental shelf.(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. The rocks series has the characteristic of hot water deposit.(3)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 rock series deposited in a anaerobic,reducing,low Eh and high salinity environment in which the organic matter is preserved easily .And the organic matter is of high mature.(4)Analyzing on the TOC of the sample, it indicates that the black rock series is of high TOC, with abundant organic matter. Contrasting the standard, we think the rock series are good source rocks. According to content of the kerogen's maceral and carbon isotope, the kerogen is typeâ… . This type of kerogen has something to do with bacterium and algae, which is accordant with organic geochemistly index. The R0 of rock sample shows that the organic matter is of high mature. we concluded that the rock series is good source rocks by researching the abundance/type/mature/ hydrocarbon bearing ability.