Editing Pembrokeshire (section)

===Geology===
The rocks in the county were formed between 600 and 290 million years ago. More recent rock formations were eroded when sea levels rose 80 million years ago, at the end of the [[Cretaceous Period]]. Around 60 million years ago, the Pembrokeshire landmass emerged through a combination of uplift and falling sea levels; the youngest rocks, from the [[Carboniferous Period]], contain the [[Pembrokeshire Coalfield]].<ref name="PVMCoal"/> The landscape was subject to considerable change as a result of ice ages; about 20,000 years ago the area was scraped clean of soil and vegetation by the ice sheet; subsequently, meltwater deepened the existing river valleys.<ref name="PVMGeology"/><ref name="HowellsGeoHistPembs"/> While Pembrokeshire is not usually a seismically active area, in August 1892 there was a series of pronounced activities (maximum intensity: 7) over a six-day period.<ref name="Davison1924"/>{{rp|184}}