Dynamics of Sedimentary Basin and Basin Reservoir(Ore) Forming System

With introduction and discussion of the dynamics of sedimentary basins and basin reservoir(ore) forming systems to be a main line,this paper generalizes and summarizes author's thoughts and viewpoints in this area. Sedimentary basins are significant in three aspects(scientific research,material needs and living environment) of earth science research and application,especially those large and medium-sized basins having a large distribution area and long development history(e.g.,oil-gas basins). A sedimentary basin is a negative tectonic unit formed in a depression of crust or lithosphere,in which sediments continuously infill in geologic history.The author defines dynamics of sedimentary basin as: A coupling dynamic system and evolution process of earth internal and external dynamics directly controlling and obviously impacting on basin subsidence and sediments infilling,and it is an important component of geodynamic systems.According to different driven force of basin depression,the origin of basin can be divided into thermal,stress,gravity and composite four types.From redefinition and revealing distribution position,evolution and relationships of basin subsidence centre,depocenter and accumulation centre,ruling out the sedimentary effects generated by non-subsidence processes,it is possible to characterize the role of subsidence and its temporal-spatial correlation and reasons with deposit and accumulation centers. The Chinese sedimentary basins are characterized by their strong tectonic activities,deep processes and intensive late reforming.All these are attributed to tectonic features of China continent.Based on the main geological processes of reforming and reforming fashions,the reformed basins can be divided into eight types.Eliminating impacts of late reforming and recovering original basin can build up a firm basis for recognition of basin evolution-reforming processes and oil-gas reservoir forming,positioning and distribution. According to the geological facts of reformed basin and the research practice of the author,ideas and regulations of study on reformed basin and oil-gas evaluation are explored and proposed;The time limit of oil-gas late-extra late reservoir forming-positioning in Chinese basins is redefined in terms of Absolute time and relative time.And also,the influences of deep processes on oil-gas accumulation,oil-gas escape and geologic effects are discussed. The research for dynamics of petroliferous basins can be divided into three major systems of basin forming,reservoir forming and assessment.In the study of basin evolution and reforming,a close correlation and interaction exist between the major systems and the sub-systems.The whole,dynamic,integrated principle for research of the basins is promoted to follow. More than 82 percent of proven sandstone-type uranium deposits on the earth coexist with oil-gas or coal fields in the same basins.Association and enrichment of the four main energy minerals within the same basin is common.But,the distribution of enrichment for different minerals is localized especially this is typical in central-east Asia.The characteristics of occurrence of multi-energy mineral deposits in all basins of mineralization domain in central-east Asia show a complex but orderly spatial distribution,close correlation of each(reservoir) ore-bearing stratum and region background,the same or similar timing of reservoir(ore) forming-positioning,related occurrence setting and reservoir(ore) forming.Also,the uranium main mineralization processes and mineralization period is in response to the regional dynamic changes,and basically consistent with the reservoir forming-positioning period of oil-gas in basins,indicating a close inherent relationships and unified geodynamic setting between them. The single sedimentary basin having multi-organic and inorganic,metallic and non-metallic minerals and water resources inside represents a basic unit and a giant complex system for multi-mineral accumulation and reservoir(ore) forming in the same basin.The system is called the reservoir(ore) forming system of sedimentary basin.In the system,the occurrence of various sedimentary minerals is not isolated.Their formation and distribution are closely related,interacting,mutually affecting,and intrinsic relationship exhibits in different forms.This system possesses its own characteristics of ore forming and reservoir(ore) forming setting.Thus,it should be treated as an independent mineralization system differing from and paralleling to other ore-forming systems. This paper discusses types of small-sized petroliferous basins and the conditions of oil-gas accumulation,the necessity and guidance for further study of mature basins.It is suitable for the system dynamics study of(stable continental) block-basin-belt(all types of tectonically active belts) in west China. The earth and basin all belong to the complex giant systems of different classes.It is an effective approach to use integrated and systematic academic thoughts to study complex science such as geosciences.In study of complex systems,the interaction of various sub-systems is the most important.In the mean while,the attention has to be drawn to the evolution of ideology and methodology,and to effort to disclose the individual characteristics of research objects.