SEQUENCE STRATIGRAPHIC GEOCHEMISTRY-A NEW PROGRESS OF GEOCHEMISTRY

Sequence stratigraphic geochemistry is a new progress of geochemistry.It mainly studies the occurrence, distribution and geochemical characteristics of source rocks under a sequence stratigraphic framework.The concept of sequence stratigraphic geochemistry was proposed by Peters et al.in 2000, and was effectively used in hydrocarbon exploration practice.Combining geochemistry with sequence stratigraphy, it can be used to study the distribution and geochemical characteristics of source rocks from a sequence standpoint and the changing rules of the geochemical characteristics of source rocks with the sea (lake) level.It can also make the genetic classification of crude oil under a sequence stratigraphic framework on the basis of oil-oil and oil-source correlation, and study the characteristics of hydrocarbon migration and accumulation.It can be eventually used to direct hydrocarbon exploration.During the course of sequence-stra-tigraphic-geochemical research, the setup of a sequence stratigraphic framework is the base, and the high-resolution analyses of biomarkers are the key.The study of sequence stratigraphic geochemistry is necessary in the exploration of continental fault lake basins in East China, where the exploration is focused on seeking for unconventional hydrocarbon accumulations such as subtle or deep reservoirs.