Undersea longwall mining subsidence with special reference to geological and water occurrence criteria in the north-east of England coalfield.

The water yield-predicted tensile strain and geological strain-water relationship occurring at four collieries with extensive undersea workings: Blackhall, Horder, Dawdon and Westoe, is examined. The water occurrences can be correlated with either faces worked in the vicinity of a major fault, areas where the amount of cover to the base of the major aquifer horizon thins appreciably or the existence of a potentially water bearing sandstone horizon within the intervening Coal Measures strata.
The water yield-predicted tensile strain and geological strain-water relationship occurring at four collieries with extensive undersea workings: Blackhall, Horder, Dawdon and Westoe, is examined. The water occurrences can be correlated with either faces worked in the vicinity of a major fault, areas where the amount of cover to the base of the major aquifer horizon thins appreciably or the existence of a potentially water bearing sandstone horizon within the intervening Coal Measures strata.