Abstract:

Restoration of the thickness eroded strata in Cretaceous/Jurassic(K/J) unconformity of Che-Mo paleo-uplift in Junggar basin is an important work for basin analysis. Based on the investigation to the methods of eroded thickness restoration, a new approach using homogeneity temperature of fluid inclusions is proposed with the burial history analysis and paleo-temperature history analysis in the area. The principle of the new method is using the differences between the homogeneity temperatures of fluid inclusions which formed when Che-Mo paleo-uplift began to rise and which formed after the erosion finished. These differences can be used to calculate eroded thickness easily. By the new method the eroded thickness in Sha 1 and Pen 4 well is 390-438 m and 361-406 m respectively. The key of the method is to separate the fluid inclusions that formed before the uplift began to rise from those that formed after the rising finished. The method can be used to restore the eroded thickness where the deposition thickness above erosion plane is larger than the eroded thickness or the eroded strata experienced multi-stage tectonic movements and developed many unconformities.

Key words: Junggar basin, Che-Mo paleo-uplift, thickness of eroded strata, fluid inclusion, homogeneity temperature, geothermal gradient