Disciplines: the head of coal the geology
word: the Zhaotong coalfield
English: Zhaotong coalfield
interpretation of the text: China's largest Neogene coal field. In Yunnan Province, northeast of Zhaotong City. North-east length of 20 km, 15 km wide, covering an area of 230 square kilometers, the landscape was oval-shaped mountain basin. The lignite reserves of about l00 million tons. Neogene Pliocene inland briquette Department from 350 to 480 m thick, deposited in the Permian and Triassic basement mountain erosion in the basin. The coal-bearing lower part of the 100 m thick, composed of alluvial lacustrine conglomerate, sandstone and shale rock World Steel Pipe News , folder l0 I thin seam. Central 40 to 200 m thick, composed of lacustrine gray and black claystone and three layers of lignite layer. Layer 2 the average thickness of 50 m 193 m thick, the region can be adopted. The remaining 2 thickness of a few meters to 30 meters, unstable. Coal measures of the upper 60 to 150 m thick, composed of lacustrine siltstone, shale rock, rich snail shell fossil. Coal type is lignite 1 (young lignite), volatile matter 52% to 59%, heat 16 to 17 MJ / kg, ash l4% ~ 25%, microscopic identification of 97% for the humic group. Save the slight charring of the trunk, petrified wood, ivory fossils in the lignite World Steel Pipe News . Coalfield-relief syncline rock angle of 3 ° to l0 ° to occasionally drop 1 to 2 m normal fault. Quaternary overburden general l0 m thick, suitable for open pit mining.