The formation of karst?cavern type carbonate oil reservoirs in lower Ordovician of 4 area in Tahe oilfield is related to weathering?denudation of fossil weathering crust.

• 塔河油田 4区下奥陶统碳酸盐岩岩溶缝洞型油藏的形成与古风化壳的风化剥蚀有关。