Definition of crab holes
Holes often met with in the bed-rock in alluvial mining. They have the appearance of having been formed by eddies of water. Crab-holes on the surface are in general due to the unequal decomposition of the underlying rocks.
After rains cray-fish are found in the muddy water and mud.
In the basaltic plains, as well as in the palaeozoic country, these holes occur, and are often the cause of serious accidents.
See Dead-men’s graves, Bay of Biscay Country. – The Gold Fields and Mineral Districts of Victoria, 1869.