A PRELIMINARY APPROACH TO THE INDO-CHINA MOVEMENT IN NORTH CHINA

The Indo-China Movement in the North China area is characterized by gentle activities of upheaval and depression. Activities of faultdown and magmatism occurred only within the marginal area of the platform, somewhat similar to the epeirogenesis. This area experienced differentiational uplift and subsidence during the early episode of the Indo-China Movement, which can be referred as the stage of depression development within the continent. It appeared as regional uplift during the late episode. There developed gently folded and/or block-folded microbasins. It is evident that differentiational uplift and subsidence activities trending Ew did occur in the North China area during the Hecynian Movement. It took the Luliang Shan Mountain as the border, higher in the west and lower-in the east. And in the east part of the platform from Carboniferous to Permian the centre of subsidence was shifted clockwise from north to south. The platform was then changed into higher in the east and lower in the west with the centre of subsidence shifted counter-clockwise from northeast to southwest during the late episode of the Indo-China Movement. It reflects the previous compressional stress southnorthward was changed into northwestward in the regional stress field. The Yuxi (west Henan) depression of the late Triassic experienced a stage of the development of stable lakebasin, providing material base for sourceded. Paleo channel sand bars and related hydrocarbon pools of "oil generated in Cenozoic and accumulated in Mesozoic" might be formed on the erosional surface formed in the late episode of the Indo-China Movement.There is also a prospect for searching of gas traps in the coal-series associated with "oil generated in Cenozoic and accumulated in Mesozoic".