- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
Castle Hill is a fault block of crinoidal limestones, interbedded calcareous shales, and massive dolomitized limestones and pseudobreccias, occurring at Tenby on the Pembrokeshire coast, southwestern Wales. The age, formerly considered to be Tournaisian, is now suggested to be Visean (Carboniferous), and referable to the Dibunophyllum zone. The new age assignment simplifies the structural interpretation, by which Castle Hill can be considered the faulted inverted limb of an overfold produced by pressure from the south.