关键词: 鄂尔多斯盆地, 演化, 基底, 中央古隆起, 铀, 油气, 古地理

Abstract:

Ordos Basin is one typical of the basins bearing organic and inorganic energy resources in China.The organic resources include oil, gas, coal and coal bed methane inside the Ordos Basin, and the inorganic-resource is mainly uranium deposits distributed at the transitional zone between basin and mountain.The orogeny around the basin controlled its basement deformation, which constrained the tectonic frame evolution of cap-rock and thus determined the process of the generation, transport and accumulation of the organic resources, such as the distribution of the source rock and coal rank etc.. Moreover, the orogenic movement and the basin evolution restricted the formation of sandstone-type uranium deposits together. Under the horizontal extrusion and vertical compaction, oil and natural gas transported from the central part of the basin to the margin and from bottom to top. In contrast, uranium-bearing inorganic epithermal fluids formed in orogens, migrated along the opposite direction under the gravity gradient. Consequently, oil and gas mixed with the uranium-bearing inorganic fluids in the basin-mountain transition zone, which induced the mutation of key physical-chemical parameters of the inorganic-fluids resulting in the precipitation and enrichment of uranium element.The symbiosis of various energy resources in Ordos Basin lays not only in the adequate conditions for the respective organic and inorganic mineralizing process, but in the coupling function of the two events.

Key words: Ordos Basin, evolution;basement, central paleo-uplift, uranium, oil and gas, paleogeography