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(5) The metamorphic characteristics of coal and rock in Junggar-Xing 'an and Tianshan-Chifeng active zones.

Junggar-Xing 'anling active belt and Tianshan-Chifeng active belt are the structural belts where coal-bearing basins are concentrated in Jurassic and Cretaceous. Carboniferous and Permian coal measures are highly metamorphic, mostly highly metamorphic bituminous coal and anthracite, with only sporadic residual basins. The Jurassic and Cretaceous coal measures are mainly lignite, long-flame coal and gas coal, which are widely distributed. Long-flame coal and gas coal are the most common in early and middle Jurassic, and lignite and long-flame coal are the most common in late Jurassic to early Cretaceous. The metamorphic degree of coal and rock tends to decrease with time. The distribution of fat coal to lean coal is limited, mostly in the subsidence center of large basins or the intersection of basins and faults, forming a high metamorphic center of lean coal and anthracite, and forming a low metamorphic zone around it.

Early Carboniferous coal measures are distributed in the northern Junggar Basin, and the metamorphic degree of coal and rock varies from gas coal to lean coal. Akchir is gas coal, fat coal in the south goes to Kutier, and lean coal in the north goes to Altay. Coking coal is distributed in Shuanghekou and Emin.

There are Permian coal measures in the northern and southern margin of Junggar Basin, and the metamorphic degree of coal and rock increases from long-flame coal to lean coal, and the lean coal is distributed between Karamay and Zhaheba. Ro and max in the northwest margin of the basin are 0.5% ~ 1.9 1%, belonging to lignite to lean coal; Ro and max in Luliang area are 0.56% ~ 1.22%, belonging to long-flame coal to coking coal; Ro and max in the southern margin of the basin are 0.54% ~ 1.33%, belonging to long-flame coal to coking coal; Ro and max in the east of the basin are 0.79% ~ 1.22%, most of which are less than 1.20%, belonging to gas coal to coking coal. The Early Carboniferous coal-bearing measures in Baoqing area of Jiamusi massif are scattered, which are composed of continental clastic rocks and volcanic rocks. The coal-bearing property is poor and unstable, and it is anthracite.

The early and middle Jurassic coal measures in Junggar basin are widely distributed, well developed and have good coal-bearing properties. The reflectance of vitrinite is 0.4% ~ 0.48% in the northwestern margin of the basin, 0.60% ~ 0.6 1% in Luliang area, 0.45% ~ 0.63% in the southern margin of the basin, 0.45% ~ 0.46% in the eastern margin of the basin and 0.46% in the western margin of the basin. An anthracite metamorphic center is formed on the north side of Manas-Hutubi line, and the metamorphic degree decreases to the periphery of the basin, steepens to the south and slows to the north, showing an asymmetric annular belt. Yining, Yurdus, Yanqi, Kumish and Turpan-Hami basins are Jurassic fault basins developed in the Variscan fold belt. There are early and middle Jurassic coal measures, and the metamorphic degree of coal and rock is long flame coal, and local coal is long flame coal to lean coal. In Yining, Yurdos, Yanqi and Kumish basins, the Vdaf is 20% ~ 50%, and the coal rank is mostly long-flame coal. Keer Street, Nanshan and Tashidian are long flame coal and gas coal, Yili is long flame coal, gas coal and fat coal, and Aiweiergou is gas coal to lean coal.

Hailaer-Erlian basin group is located in Hualixi fold belt, and consists of more than 100 fault basins, which are distributed in NE and NE directions. The coal-bearing series belongs to Lower Cretaceous, and the degree of coal and rock metamorphism is low, almost all of them are lignite. Only Labuzalin, Wujiu and Yimin basins are long-flame coals with east-west distribution. There are lean coal and anthracite in Shijiangshan. The vitrinite reflectance Ro, max measured by Xidacang is 0.34% ~ 0.4 1%, which is equivalent to dark lignite, and Vdaf is 44.06% ~ 45. 19%, which belongs to hard lignite. The Vdaf measured in this area is 42% ~ 48%, which changes stably and belongs to hard lignite.

Songliao basin formed a faulted basin in Yanshan period, and coal-bearing series developed from late Jurassic to early Cretaceous, and the metamorphic degree of coal and rock varied from lignite to anthracite. Between Changling and Daqing, a high metamorphic center of lean coal and anthracite is formed, surrounded by fat coal and gas coal belts, which are wide and slow in the north, west and south and narrow in the east. There are lignite distributed in the north of the basin, anthracite, lean coal and lean coal in the west and south of the basin.

Sanjiang basin group is located in Jiamusi block, and the coal-bearing rock series developed from late Jurassic to early Cretaceous. The metamorphic degree of coal and rock is complex, ranging from lignite to anthracite, with long-flame coal and gas coal as the main ones, followed by chemical fertilizer and coking coal, and thin and thin coal and anthracite are less. The metamorphic center of high metamorphic bituminous coal or anthracite is formed in some divided basins, and the metamorphic degree gradually decreases towards the edge of the basin. For example, the middle of Jixian basin is coking coal, and the periphery is fat coal and gas coal; Hua Shuang and Baoqing basins are coke, chemical fertilizer and gas coal from the inside out; The middle part of Boli Basin is anthracite, and gradually becomes long-flame coal. Jixi basin changed from lean coal to gas coal from inside to outside.

Refer to Atlas of Coalbed Methane Basin in China, Carboniferous Coal and Rock Metamorphic Degree Map in China, Permian Coal and Rock Metamorphic Degree Map in China, Mesozoic Coal and Rock Metamorphic Degree Map in China, Cenozoic Coal and Rock Metamorphic Degree Map in China and Coal and Rock Classification Comparison Table (Steps).