Geology and coal resources of the Thar Coal Field, Sindh Province, Pakistanстатья из журнала
Аннотация: The Thar coal field is located in the Thar Desert of southeast Pakistan in eastern Sindh Province.The coal field area covers about 9,000 square kilometers with dimensions of 140 km (north-south) by 65 km (east-west); the field area is bounded by the Pakistan-India border to the north, east, and south.The field area is covered by northeasttrending longitudinal stabilized sand dunes with topographic relief of up to 100 m.The Thar is essentially roadless with tracks through the sand being the principal transportation routes mandating four-wheel drive vehicles.The Mirpur Khas -Khokhropar Branch Railroad traverses the desert just northwest of the field area.Total coal tonnage for the field is 78,196,555,SOOmetric tons.The coal is lignite B in rank with an average as-received heating value of 5,333 Btu, as received sulfur percentage of 1.57, and as-received ash percentage of 8.83 percent.The average dry and ash-free heating value for the Thar coals is 12,322.Average as received moisture content is 48.57percent.Nine drill holes in the south-central part of the field contain more than 24 m of total coal; six of these nine drill holes contain coal beds greater than 20 m thick.Drill hole TP-3 contains a bed of coal 27 m thick containing only three partings in its upper part measuring 1.05 m, .9m,and .41m thick.The shallowest coal in the field lies at a depth of 123 m; the deepest coal (depth to 1st coal bed) is at 245 m.The field contains 3,962,385,900metric tons of coal at a depth of less than 150 m.All of the drill holes in the field were located in interdune areas at the lowest elevation possible; because the surface relief of the sand dunes of the Thar Desert is as much as 100 m, the Thar coals between drill holes will probably be covered, on average by an additional tens of meters of dune sand.A structural dome in the south-central part of the Thar coal field has elevated the thickest coals in the field closer to the surface.A north-easterly trending fault forms the boundary of the Thar field in the southeast part of the field area; east of this fault, the coal-bearing rocks were uplifted as much as 150 m and were probably eroded prior to deposition of the overlying alluvium.The Rann of Kutch fault zone probably represents the maximum southern extent of minable coal in the field area.Thar coals thin greatly northward, eastward, and westward in the northern half of the field area; to the south, relatively thick coals may be present west of the presently-drilled area.On the basis of paleontological information the Thar coals are Paleocene to Eocene in age; probably early Eocene.Available evidence indicates that the Thar coals may have been deposited in a raised-bog environment landward of a north-trending coastline of a sea to the west.
Год издания: 1994
Авторы: James E. Fassett, N.A. Durrani
Издательство: United States Department of the Interior
Источник: Antarctica A Keystone in a Changing World
Ключевые слова: Geotechnical and Geomechanical Engineering
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