Definition of mud capping

A practice used to break up large boulders of ore or rock in a work area such as a stope or pillar. A capped piece of explosive is laid on the boulder and is "capped" with either mud or wet muck to somewhat contain the force. When set off, the explosive charge is intended to break up the boulder. The explosive may be placed under the boulder such that the boulder itself contains the force and is shattered in the process. This is a very inefficient method of breaking up large boulders. Block holing is preferred.