Indiana’s limestone deposits were formed aeons ago when the land was the floor of an ancient sea, peopled with small, shell-bearing animalcules. Dying, these formed massive beds of oolite.

Cave explorers have pushed through narrow gaps in rocky walls to uncover an extra 100 metres of tunnel on South Australia's Limestone Coast, with hopes it may link separate caves together.

SAN ANTONIO - A groundbreaking historical discovery has finally pinpointed the quarry that provided the limestone used to construct the Alamo, solving a long-standing mystery about the origins of ...