Cockpit Country developed from a White Limestone plateau laid down on top of older, Yellow Limestone, itself laid down on the underlying igneous rock. This plateau emerged from the sea about 15 million years ago and its boundaries, together with the transition from true cockpits to the degraded cockpit karst of Dry Harbour Mountains, define a geological boundary of Cockpit Country.
These boundaries are:
- West: The Montpellier-Newmarket Trough
- North: Duanvale Fault (or Duanvale “Cliff” according to recent research by Prof. Simon Mitchell of UWI).
- South: Rio Minho - Crawle River Fault as far as Nassau Valley, where it dissipates, and then by the southern boundary of Nassau Mtns
- East: Dry Harbour Mountains form the eastern boundary, though (see sidebar) there is some discussion over the exact location of this transition.