The Geochemical Characteristics And Formation Mechanism Of Excellent Source Rock In Marine Hydrothermal Sediment Area In North Region Of Guizhou

Hydrothermal sediment is the process of the Earth's internal matters and energy releasing to the near-surface,including complex crystallization,metasomatism,filling and so on.It also refers to the sediment of the process.The research on the geochemical characteristics and formation mechanism of the hydrothermal source rocks is very limited.The excellent source rock in hydrothermal area is very important because it not only is a basic study,but also has theoretical and practical significance on petroleum exploration.This study will focus on the black shale in the Niutitang formation of the lower Cambrian at the north of Guizhou province.The samples are collected from Wenshui Village in Baihuahu Country of Qingzhen County,Zhongnan Village in Songlin Town of Zunyi City,Lianxing Village in Guiguo Town of Zhinjin County,Bijie City,Yangtiao Village in Xiasi Town of Majiang County,Jiumen Village in Nanao Country of Danzhai County,and other three areas used as comparison.The analytical methods adopted are the elemental analysis(X-ray diffraction techniques,rock pyrolysis analysis,gas chromatography mass spectrometry(GC-MS).It is aimed at getting the details of major elements,trace elements,rare earth elements and TOC of the petroleum source rocks.All geochemical characteristics of the hydrothermal source rocks,combined with the hydrogen,oxygen isotope analysis and compounds of biomarker analysis,will be used to determine if the sources of the organic matters are associated with Hydrothermal sediment and to study the influential factors of the formation of hydrothermal source rocks.This research shows that the petroleum source rocks in the Niutitang formation of the lower Cambrian at Yangtiao Village in Xiasi Town of Majiang County and Jiumen Village in Nanao Country of Danzhai County,close to the center of the hydrothermal solution,have the most obvious features of sediment and the best evaluation.Besides,excellent source rocks from other areas also have traits of hydrothermal sediment.Further study demonstrates that hydrothermal solution brings matters and energy from the crust to the seabed,which can increase the primary productivity of the organic material.This research also finds that the petroleum source rocks distribute around the center of the hydrothermal solution regularly and speculates that there is certain relationship between hydrothermal sediment and Cambrian Explosion.Based on the previous research result,the theory of theformation mechanism and model of the excellent source rocks in the hydrothermal sediment area will be built in this thesis.