川中乐山-龙女寺古隆起奥陶系风化壳古地貌恢复方法及其特征

风化壳古地貌与岩溶储层、古地貌圈闭密切相关。碳酸盐岩风化壳岩溶作用的发展及演化明显受控于当时的古地貌形态,而古地貌又控制着地表和地下岩溶水流的流向,进而控制了碳酸盐岩风化壳岩溶作用带内的孔洞发育。川中乐山-龙女寺古隆起经历加里东到海西期120Ma的风化剥蚀,岩溶作用十分发育,奥陶系储层储集空间均由次生溶蚀改造而成。结合本区地层特征,选取适当的层位用"印模"法进行岩溶古地貌恢复,并划分出岩溶高地、岩溶斜坡和岩溶洼地三种地貌单元及次级单元,分析了各个分区特征。

Restoration method of Ordovician weathering crust paleo-geomorphology of leshan-longnv temple paleohigh and its features in central Sichuan

Weathering crust paleogeomorphology is closely re- lated with karst reservoir and paleogeomorphological trap. The development and evolvement to karstification of car- bonatite crust of weathering are obviously controlled by palaeogeomorphology conformation at that time,while the flow direction of cavern water of earth's surface and inter- stratal are controlled by palaeogeomorphology,and then the development of hole and cavern in the karstification zone of carbonatite crust of weathering is also controlled. Undergoing the weathering dedudation of 120Ma from Ca- lidonian to Hercynian period,Karstification is very devel- oped in Leshan-longnv temple,and the Ordovician reser- voir space is reformed from secondary dissolution pore. Considering the strata characteristics,this paper selects appropriate layers to restore the karst paleogeomorpholo- gy by using copying method,and then divides karst land- form into three paleogeomorphological units,namely height,slope and depression and some other sub-units. The features of each unit are analyzed at the same time.