Editing Pembrokeshire Coast Path (section)

==Geology==
All the rocks underlying the surface are more than 300 million years old, but the coastline as seen today has been much subjected to the effects of coastal and river action and, in places, to events which occurred during the [[Last Glacial Period|Ice Age]].

The oldest [[igneous]] and volcanic [[Precambrian]] granites outcrop on Ramsey and at the southern tip of the peninsula. Later [[Cambrian]] sedimentation produced sandstones, visible on the northern coast of St Brides Bay (and which were used in the building [[St David's Cathedral]]). Subsequent [[Ordovician]] fine muds dominate the northern Pembrokeshire coast, but volcanic activity has complicated the whole. The later [[Silurian]] Period saw the creation of limestone and shale, visible along the southern [[Marloes]] peninsula.<ref name="PembrokeshgireCoastal" /> The coast of St Brides Bay is backed by [[Coal Measures]] rocks dating from the late [[Carboniferous]] Period as is the coast between Tenby and Amroth and the upper reaches of the Cleddau. Much of the rest of Milford Haven is fronted by [[Old Red Sandstone]] from the preceding [[Devonian]] Period along with all of the Dale peninsula and Skokholm Island. [[Carboniferous Limestone]] dating from the early Carboniferous forms much of the southern coast traversed by the coast path notably between Freshwater West and Stackpole and between Lydstep and Tenby.<ref>British Geological Survey, 1994 ''The Rocks of Wales'' 1:250,000 scale geological map BGS/NERC</ref>

Subsequent earth movements, erosion by ice and water, and changes in sea level have further affected what we see today.