Main Controlling Factors and Formation Mode of Geothermal Anomaly in Eastern Chenghe Mining Area of Weibei Coalfield

Table 4

Statistics of geothermal gradient of stratum.

Stratum	Noncoal strata (°C/km)	Coal-bearing strata (°C/km)	No. 5 coal seam/km (°C/km)	Ordovician strata (°C/km)
Gradient ranges	14~4805	14~82.5	21~101	15~88
Average	31.1	42	54.2	39.7