Yanshi Guanmao mining area is located on the north side of Songshan Mountain. ZK 14449 Borehole Quaternary loess thickness is 1 10m. The Paleogene and Neogene sediments of borehole ZK 20425 and borehole ZK2082 1 contain bauxite and Taiyuan Formation biolimestone breccia (photo 6.2). It shows that Carboniferous in Songshan Uplift was lifted to the surface and denuded in Paleogene and Neogene. In Quaternary, Guanmao mining area continued to decline and accepted sedimentation. There are large areas of Cambrian limestone exposed near Songshan Uplift and Shaolin Temple. In Paleogene and Neogene, the Carboniferous overlying Songshan Uplift was completely denuded.
Hucun mining area in Qinyang is located at the intersection of Taihang Mountain uplift and plain, with graben structure as a whole. Carboniferous and Permian are exposed in the graben composed of NE-trending normal faults, while Ordovician is mainly exposed outside the graben. The Carboniferous outside the graben has been completely eroded, and the remains appear in higher places. Taihang Mountain mainly uplifted in Quaternary (Chen Wu, 1999), and the erosion of bauxite outside the graben in Hucun mining area mainly occurred in Quaternary.
Jiyuan Summer Night Mining Area is located on the north bank of the Yellow River, which is a horst structure on the whole, bordering the Yellow River in the south and Shi Feng Valley in the north. Bauxite is distributed on the horst structure formed by F, 1F2 near the east-west fault, and the height difference with the valleys on both sides is more than1000 mm. The Permian system is exposed in the valleys on both sides, and Quaternary loess deposits and loose river deposits are distributed on the horst (Wang Chen, 2006), indicating that the mining area had obvious structural movement in Quaternary, which made bauxite relatively rise to the surface.
The boundary fault distance of Cenozoic basin in Goutou mining area of Xin 'an County is more than 400 meters, and the thickness of Paleogene, Neogene and Quaternary in the basin is about 200 meters. In the borehole drilled in the basin, bauxite bodies appear at the depth of 380 meters, and bauxite bodies appear in the surface Paleogene and Neogene breccia (photo 6.2). It shows that in Paleogene and Neogene, bauxite in the uplift area near the mining area began to be denuded, and in Quaternary, the mining area declined to accept loess deposition.
Fig. 6.2 Bauxite breccia of Paleogene and Neogene
The west section of the new bauxite mining area in Shaanxi Province was cut into a faulted basin by the NE-trending fault, and the benxi formation in the basin was preserved, which controlled the distribution of bauxite and formed the bauxite areas such as Qiligou, Wanggudong, Zhijian and Diya.
The strata of Daimanzhai uplift are gentle monoclinic to the south and east, with undeveloped faults and a series of large bauxite deposits. In Jiaozuo-Jiyuan area, Taihang Mountain has a large uplift and a large piedmont fault distance. Only the ore-bearing rock series in benxi formation remain in the faulted basin on one side of the mountain, forming small and medium-sized bauxite deposits (points); Songji area can be divided into Songshan and Jishan uplift. The north side is relatively flat, and a series of bauxite deposits appear. On the south side of the uplift, the fault distance is large, the descending plate is covered with thick sediments, the ascending plate is strongly eroded, and bauxite is completely eroded. There are bauxite spots on the south slope of Songshan, east of Ludian, and only small-scale bauxite spots appear intermittently on the south side of Songjilong.