The natural gas in Ordovician weathering crust reservoir in the Central Portion Gas Field in Ordos basin is source-mixed gas of tipper Paleozoic coal-typed gas with Lower Paleozoic oil-typed gas.

• 鄂尔多斯盆地中部奥陶系风化壳天然气为上古生界煤成气和下古生界油型气混源气。