苏北第三系成熟演化指标与深度关系的3种模式

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

在苏北盆地下第三系,4项成熟演化参数(Ro、甾烷成熟指标SM、蒙脱石层间比S、裂变径迹)与深度呈由浅变深的平行线分布关系。分析认为,这些样品分别产生于不同的构造-沉积埋藏史背景,浅的代表构造抬升型,最深的代表短时加温型,次深的代表长时加温型。3种模式的建立为构造抬升地区恢复地层剥蚀量提供了可选择的依据。

The relationship between the four maturity indexes (Ro, sterane parameter αααC29-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.