The most widespread type of masonry work is the erection of solid brick masonry using individual bricks set in mortar. âLight masonry,â consisting of two parallel face walls each one-half a brick thick and filled with a light concrete, loose slag, or another insulating material, is sometimes used.
A sinkhole, also known as a cenote, sink, sink-hole, shakehole, swallet, swallow hole, or doline (the different terms for sinkholes are often used interchangeably), is a depression or hole in the ground caused by some form of collapse of the surface layer.
Sinkholes are common where the rock below the land surface is limestone, carbonate rock, salt beds, or rocks that can naturally be dissolved by groundwater circulating through them.