Fig. 4

Photos of maceral of Benxi Formation 8 # coal sample. (a) The maceral photos of coal samples with a depth of 2803.10 m. Under the oil-immersed reflected light, the content of vitrinite is more, the vitrodetrinite can be seen, and there is also a small amount of inertodetrinite; (b) The maceral photos of coal samples with a depth of 2803.50 m. Under oil-immersed reflected light, the vitrinite content is very high, and most of them are collotelinlte; (c) The maceral photos of coal samples with a depth of 2804.60 m. Under oil-immersed reflected light, the vitrinite content is also very high, and most of them are collophanite, and also contain a small amount of inertodetrinite; (d) The maceral photos of coal samples with a depth of 2805.34 m. Under oil-immersed reflected light, the vitrinite content is also very high, and most of them are collophanite; (e) The maceral photos of coal samples with a depth of 2806.78 m. Under oil-immersed reflected light, the vitrinite content is also very high, and contains a small amount of inertodetrinite; (f) The maceral photos of coal samples with a depth of 2807.62 m. Under oil-immersed reflected light, the vitrinite content is also relatively high, but it is reduced. The content of inertinite increased, among which the content of inertodetrinite, fusinite and semifusinite increased; (g) The maceral photos of coal samples with a depth of 2808.57 m. Under oil-immersed reflected light, the vitrinite content is further reduced compared with the sample at 2807.62 m, and the inertinite content is increased. The content of fusinite and semifusinite increased; (h) The maceral photos of coal samples with a depth of 2810.09 m. Under oil-immersed reflected light, the vitrinite content increases compared with the sample at 2808.57 m, and the pores are mostly filled with clay minerals; (i) The maceral photos of coal samples with a depth of 2811.59 m. Under oil-immersed reflected light, the vitrinite content is reduced compared with the sample at 2810.09 m, the pores are mostly filled with clay minerals, and a small amount of pyrite appears; (j) The maceral photos of coal samples with a depth of 2811.87 m. Under oil-immersed reflected light, a large number of fusinite and semifusinite can be seen. And there are more clay minerals; (k) The maceral photos of coal samples with a depth of 2812.60 m. Under oil-immersed reflected light, the vitrinite content is relatively low, most of the pores are filled with clay minerals, and a large amount of pyrite can be seen; (l) The maceral photos of coal samples with a depth of 2812.90 m. Under oil-immersed reflected light, the content of vitrinite is also relatively low, a large number of fusinite and semifusinite bodies can be seen, and a large amount of pyrite can be seen.