The rugged karst terrain that is developed on the dolostones of the Miocene Cayman Formation on Grand Cayman includes numerous large cavities that formed through the activity of tree roots. The surfaces of those cavities are coated with laminated calcrete crusts that are up to 8 cm thick. These calcrete crusts, which are formed of calcite, dolomite, and locally manganese precipitates, formed though the action of the plant roots and their associated microbes. As such, they are excellent examples of non-horizontal calcrete crusts that developed in the shallow subsurface rather that on the subaerially exposed surface