Clay Veins: Their Physical Characteristics, Prediction and Support.
Proc 4th Conf on Ground Control in Mining Morgantown West Virginia, 1985 Jul; :212-219
Clay veins, also referred to as clay or clastic dikes, have been responsible for numerous underground injuries and fatalities. These hazardous structures are also responsible for increased production costs during all phases of mining. For these reasons, the Bureau of Mines has investigated the physical characteristics of and roof instability problems associated with clay veins in order to make support and other mining recommendations. In addition, the occurrence and origins of clay veins were examined to determine whether or not the structures could be projected into unmined portions of the coalbed.
Proc. 4th Conf. on Ground Control in Mining, Morgantown, West Virginia, July 22- 24, 1985, PP. 212-219