关键词: 铝土矿, 重力测量, CSAMT测量, 找矿靶区, 深部找矿

Abstract: Yushan-Lizhuangzhai Area is located in the south of North China block，belongs to the east part of the bauxite（clay）-rich metallogenic belt in Shanxian-Mianchi-Xin'an area.It is the most important metallogenic area of bauxite deposit with high quality in Henan Province.In order to comprehensively understand the bauxite resources potential in Henan Province，gravity survey，controlled source audio-frequency magnetotelluric measurement （CSAMT），transient electromagnetic measurement （TEM），seismic measurement and high precision magnetic survey on the surface are adopted，and the geophysical prospecting tests for deep bauxite deposit are carried out.The test results show that gravity survey has a good result on circling the tectonic structures，and the bauxite deposits are generally distributed on the transient belt between the high gravity belt and the low gravity belt； CSAMT survey can reflect the fluctuation of the Ordovician limestone beddings，which can help to judge accurately the spatial distribution of the concealed bauxite orebodies.According to the test results，gravity survey and CSAMT survey are adopted to conduct integrated metallogenic prediction of the study area.The metallogenic prediction study results indicated that:①in the study area，the bauxite deposits are mainly distributed in the depression areas near the margins of the paleo-uplifts，the bauxite deposits occur on the unconformity surface of Lower Paleozoic Ordovician carbonate rocks，strictly controlled by karst landforms，the erosion surface with different size depressions and funnels are the locations of the bauxite orebodies；②2 large-scale bauxite deposit areas are submitted in Houling and the north of Lizhuangzhai in Mianchi County，as well as a deep prospecting target area in Lizhuangzhai，among of them，3 bauxite orebodies are discovered in the north of Lizhuangzhai with a resources reserves 56.830 2 million tons，2 orebodies in Houling with a resources reserves 95.673 5 million tons，Lizhuangzhai orebodies are buried in a depth of 300~700 m and the area is a good target for further exploration；③through the above-mentioned geophysical tests and drilling verification results，it is determined that the geophysical methods for deep bauxite deposits prospecting predication in Henan Province are gravity survey and CSAMT measurement，the former can be used to circle the bauxite metallogenic favorable area，while the latter can be adopted to determine the spatial characteristics of the concealed bauxite orebodies.

Key words: Bauxite, Gravity survey, CSAMT survey, Prospecting target area, Deep prospecting