292 THE P1CT(3U COAL FIKLD — POOLE. 



fault for the same reason, tlie lino of inferior coal beino- parallel 

 to the rising ground of Millstone Grit beyond the fault. At the 

 opposite end the deterioration led to the stoppage of the uyjper 

 levels in the Black Diamond area, and the lowest levels north in 

 the Acadia area. The Black Diamond exploratory level No. 4 

 followed the seam until it was reduced to 2 feet of coal. At the 

 slope bottom of that Colliery No. 10 level cut a fault an upthrow 

 47 feet to the east that only began at the Acadia barrier 400 feet 

 distant, and which coincides on the surface with the foot of rising 

 ground that extends in the same direction northward. The fire- 

 clay band, which is persistent in the Acadia seam, is not repre- 

 sented in the Albion main seam. It rapidly thickens as the 

 seam goes northward in the Black Diamond area, and forms the 

 bottom of all the workings north of the furnace pit At number 

 8 chute, the furthest north, it was found to be 9, feet thick with 

 no coal below it. The section of the seam above it being there 

 as follows : — 



Ft. In. 



Coarse coal 1 



1 



Fair coal 1 4 



Splint 4 



Grey fireclay 5 



Splint 3 



Fair coal 2 2 



Coarse coal 3 



Fair coal 7 



Coarse coal 1 



Total 8' 4" 



The same change for sandstones to shales noted in the measui'es 

 overlying the Acadia seam has been proved in those beneath, the 

 borehole at the fourth bottom on tlie Acadia slope side pierced 

 sandstones and tapped water, so did the horizontal stone drift 

 started at a point 1260 feet down the Black Diamond slope on 

 the north side, while a drift driven back from the Acadia seam 



