Height of Mining-Induced Fractured Zones in Overlying Strata and Permeability of Rock with Nonpenetrative Fractures

Figure 4

Drill-core photographs of JE1 borehole: (a) RQD is zero of CZ; (b) first fresh vertical fracture and smaller RQD of TFZ; (c) initial high angle fracture and larger RQD of NFZ.