The Gray Sandstone Group is a late Silurian lithostratigraphic group (a sequence of rock strata) in west Wales. The strata are exposed in the coast around the Milford Haven area; outcrops occur either side of Marloes Bay. Besides quartzitic sandstones and mudstones, sandy rottenstones are found at outcrop. Fossils within the rottenstone beds include brachiopods and corals.[1] The rocks of this group have also previously been known as the Gray Sandstone Series.[2]

Gray Sandstone Group
Stratigraphic range: Wenlockian (Silurian)
Thick sandstone units of the Gray Sandstone Group outcropping on the coast, just west of Marloes Sands
TypeGroup
UnderliesRed Marls Formation
OverliesCoralliferous Group
Thicknesscirca 274 - 609m
Lithology
Primaryquartzitic sandstones
Othermudstones
Location
CountryWales
Extentsouth Pembrokeshire

References

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  1. ^ Howells, M.F. 2007 British Regional Geology: Wales (Keyworth, Nottingham. British Geological Survey) pp86, 89-90
  2. ^ http://www.bgs.ac.uk/Lexicon/lexicon.cfm?pub=GSA (BGS on-line lexicon of rock units)