(Q) 2. Geology
The mine property of Quinsam Coal Corporation is within the #1 Seam and the #3 Seam in the Comox coalfield on the Vancouver Island near Campbell river at a latitude of 49056'08'' and longitude of 125029'10''. The Upper Cretaceous Nanaimo Group (Comox formation) consists of 3 sedimentary coal bearing basins: Middle Quinsam lake area, Lower Quinsam lake area and Chute Creek area.
The Middle Quinsam lake area has 2 lagoonal cycles of deposition of highly volatile bituminous A rank coal interbedded with mudstone, siltstone and sandstone. The #1 Seam belongs to the lower cycle and extends up to the base of #2 Seam. The #2 Seam and #3 Seam belong to the upper cycle. Figure Q1 shows the lithology of the upper cycle and the lower cycle from the surface to a depth of 100m. Minor high-angle reverse faulting occurs on the western margin of the basin, where the Comox formation is in contact with granites of the early to middle Jurassic Island Plutonic Suite.
The lithology overlying the #1 Seam is significantly different from that over the #3 Seam. The #1 Seam is overlain by grey shale, which grades into a slightly more competent silty shale about 0.6m up in the roof. Figure Q2 reveals the borehole QM2 located at 4 Mains (the Supply Road) 31 crosscuts, 7.6m (25 feet) East, 6.13m long in the roof of the #1 Seam. It shows mudstone, shale and the interbedding of 1.8m siltstone.
The roof of the #3 Seam is a medium grained, massive sandstone with occasional joints.
Over the Quinsam Coal property, there are about 17 faults. Most of them strike NW-SE approximately and have suffered from a displacement of 2 to 4m on average. The rest faults are oriented in other directions, i.e. N-S or NE-SW (Figure Q3). The dip angles of the faults vary and are more than 500. There is a major fault striking in the E-W (approximate) with 18m vertical shift. This fault extends from Long Lake and is situated between the 2 North and 4 South mines.
There is no running water throughout the property of Quinsam Coal but the humidity is enough to cause damp atmosphere. The #7 panel (currently being depillared) and #9 panel (currently being developed) in 2 North Mine are wet, with water dripping in some places. Dry drilling and cutting collection are practiced for roof bolting.
The #1 coal seam is 3.0 to 4.9m thick containing 2.0 to 3.7m of coal separated by two or three mudstone partings and bone layers, all less than 0.3m thick. The #1 Seam is the thickest in the central part and gradually thins and pinches out along a northern depositional margin. In the South-central part of the area, a thin rider seam, 0.5 to 0.8m wide, lies 0.3 to 3.7m above the #1 Seam. The #2 Seam lies above the #1 Seam.
Within the boundary of Quinsam Coal, the #1 Seam contains a very soft mudstone layer of variable thickness about 2m below its roof. The #1 Seam dips 50 to 70 (12%) towards East approximately.
The #3 Seam lies 30.5 to 39.6m above the #2 Seam. The #3 Seam is 3.7 to 4.6m thick containing 1.8 to 3.0m of coal. The coal in the #3 Seam occurs in 4 bands separated by mudstone partings. The #3 Seam has extreme lateral variability, and was explored mainly in the area South of Quinsam river.
Figure Q1 Stratigraphy of Comox formation up to 100m depth
Figure Q2 Borehole QM2 histogram (Source: Last page of C. Mark's report)
Figure Q3 Geological structures in Quinsam Coal (Source: Plan#1992 2-N from the mine)
Figure Q4 Depillaring procedure in 2 North Mine at #1 Seam (Source: mine information)
Figure Q5 Partial extraction procedure in 4 South Mine at #3 Seam (Source: mine information)
Figure Q6 Mine layout of 2 North Mine (Source: Plan # 97-E-205 ug)
Figure Q7 Depillaring and breaker post installation (Source: mine information)
Figure Q8 Extended cut sequence and simultaneous bolting (Source: mine information)
Figure Q9 Roof bolting and grip plate (Source: Roof bolting training module from mine)