The evolution of groundwater hydrodynamic field and origin of groundwater in sedimentary basins control the distribution patterns of chemical field of ground water.At the margin of a basin

groundwater desalinates due to the downward infiltration of atmospheric water

while in the central depression

groundwater desalinates due to discharge from mudstone under compaction.In contrast

groundwater concentrates in bypassing discharge area.During centrifugal and endoeentric flow processes

groundwater concentrates and gets salinized

forming a relative high salinity zone in the bypassing discharge area.Centrifugal flow from mudstone compaction serves as the main driving force of hydrocarbon migration in sedimentary basins and provides a favorable environment for large scale hydrocarbon accumulation during the bypassing and discharging of ground water.Moreover

it also can contribute some hydrocarbons to the lithologic

stratigraphic

fault traps located on the pathway of hydrocarbon migration.The advancement of endocentric flow may destroy the earlier hydrocarbon pools and also possibly lead to the formation of hydrodynamic traps at specific geologic conditions.