Abstract:

After multidisciplinary analysis of the sectional and planimetric characteristic of the unconformities in the Tazhong uplift，as an example，the spatial patterns and distribution characteristic are elucidated and the structural evolution in the Palaeozoic is probed.In overlapped basins，which usually undergo multiple superposition of tectonic movements，many unconformity interfaces are developed.There are some rules in the distribution and spatial pattern of the unconformities，from the uplifted area to the sunken area，the highangle and superimposed unconformities，lowangle truncated or onlayed triangle unconformities and parallel unconformities or conformities develop respectively.The differences between the spatial patterns of the unconformities are important to control the oilgas migration and accumulation.Considering the oilgas geologic conditions in the Tazhong uplift，the onlap unconformities traps in the Devonian are expected.

Key words: overlapped basin, unconformity, spatial pattern