A mat assembly including a planar mat body formed to cover a preselected area of a surface region. The preselected area partially defines a volume of ground to be broken by explosion therein. The mat body includes one or more layer elements. The mat body has an engagement surface for engagement with the preselected area. The mat assembly includes a skirt element connected with the mat body having an external portion extending from the mat body, for at least partially restraining matter ejected from the volume of ground upon initiation of the explosion.