THREE MODELS OF RELATIONSHIP BETWEEN THE MATURITY INDEXES AND THE DEPTH IN THE NORTHERN JIANGSU TERTIARY BASIN

The relationship between the four maturity indexes (R_o,sterane parameter αααC₂₉-S/(S+R),mixed layer of illite/smectite and fission track) and the depth in the northern Jiangsu Tertiary Basin showed a parallel distribution from shallow to deep.The samples for study were from different sedimentary and structural settings with variable bury history.The shallow one represented structural uplift,the deepest one underwent short time heating,and the medium was long time heating type.It provided optional bases for estimation of erosion thickness in uplift areas.