The limestone used contains sufficient quantities of clay and/or silica.
Many limestones contain fossils, and some are made up almost entirely of skeletal material.
Underneath there is a base of limestone containing numerous 100 million year old marine fossils from when this area was under the sea.
Knowing that limestone doesn't contain any gold deposits, they abandoned the cave as a mining opportunity, and left it alone.
A black limestone containing fossil corals of the Carboniferous Period, some 325 million years ago.
The Gulf basin is all limestone and sandstone, containing porous geological traps.
Further north is the White Cliff, where the exposed limestone contains fossilised corals.
The limestone contains mammalian fossil deposits of Pleistocene age.
In Dunham's classification, a mudstone is any limestone containing less than ten percent carbonate grains.
Built of locally-quarried Tennessee marble and limestone around a central hall floor plan; contains hand-carved cornices.