| Based on the full collection of late Paleozoic coal-bearing basin on the basis of geological data and adopting method of field geology survey and indoor synthetic analysis, in coalfield geology, sedimentology and geology for guidance aimed at providing the basis for carboniferous-Permian coal seam exploitation and production layout in resesrch of carboniferous-Permian coal seam occurrence regularity and control of action research in datong coalfield.1.The thickness of No.2coal seam of TaiYuan formation in upper Carboniferous systerm at Sitai、Majiliang which are locating at the northern part of DaTong coalfield is2-5m,so does its thickness at Nanyangpo、Zengzifang and Xintun which are locating at the southern part of DaTong coalfield; The thickest No.2coal seam locates at the area of Xiaoyu and Wangping which is9m; In the middle of DaTong coalfield, the thickness of No.2coal seam is between0and1m at mountain Ta and Pan home kiln and Madaotou which is missing. No.3coal seam distributes meanly in the middle of DaTong coal field, and the thickness is usually3-5m, the thickest is at the area of Xiaoyu and Wangping which is10m; and there is no No.3coal seam at Sitai and Tongxin in the north and Nanyangpo in the south. There are No.5coal seam in the whole area of DaTong coal field,the thickness at Sitai and Tongxin shaft area in the north and from Madaotou to Nanyangpo in the south is7-9m, and the thickest is thicker than12m; the thickness in the middle north of Dongzhouyao and Mountain Ta is a little thinner, which is4-7m. No.8coal seam distributes in the whole area which is mostly3-5m. the thickness at the south of Nanyangpo、 Mountain Ta and Majiliang is5-7m, and only the thickness at the south central of Madaotou shaft area is less than2m. No.4coal seam of ShanXi formation in lower Permian meanly distribute at the area of mountain Ta and Dongzhou kiln in the north central of coal field, and the thickness is3-5m; the thickness at the area of Wujiayao、 Xiaoyu and Wangping is about3m; The thickness at the south of Panjiayao till to Madaotou is only0-1m; and the coal seam in the south of Nanyangpo is missing.2.Taiyuan group of upper carboniferous contains a total of10coal seams in Datong CoalField.No.8,5,3,2seams are main coal seams. Shanxi group of Lower Permian include4coal seams named Shan1, Shan2, Shan3, Shan4.Only parts of Shan4coal seam can be exploited. Each coal seam bearing characteristics depends on its sedimentary envi-ronment. No.10and No.9coal seam are formed in frequent shunt bay environment of the main river diversions, therefore, No.8coal seams formed in partial development the long-term stability of the peat swamp environment.After the formation of the No.5coal Seam, the deposition environment of Datong enters into the meandering-river depositional system stage until Shanxi group of the Early Permian, gradually evolved into the braided river depositional environment, Then controling coal accumulation characteristics of the coal seams of the upper part of Taiyuan group of upper carboniferous and Shanxi group of the Lower Permian.Leading to the distribution and thickness of later coal seams are different.3.Da Tong coalfield is a synclinal basin. In the middle of the basin,the major structure of the coalcontrolling is grabenstructure,and the graben-structure is divided the coal seam of the original unity into several blocks. The structure is more complicated in the southeastern part of the coalfield. In the influence of the fault thrust,the occurrence of coal seam changes violently in dip of the coal seamincreases and the the coal seam reverses.4. Lamprophyre intrudes the coal seam of the No.shan4、No.2、 No.3-5and No.8as the rock bed in the Ta Shan of Da Tong coalfield,the bifurcation of the lamprophyre destroys the the original structure of the coal seam. The coal seams above and below of the lamprophyre become natural coking and lose its original value.Instrution of the lamprophyre makes the local coal seam unminable. |
PDF Full Text Request