Portishead Pier to Black Nore SSSI () is a 71.8

hectare The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100- metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is ...

geological Site of Special Scientific Interest A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle o ...

near the town of Portishead in

North Somerset North Somerset is a unitary district in Somerset, South West England. Whilst its area covers part of the ceremonial county of Somerset, it is administered independently of the non-metropolitan county. Its administrative headquarters is in the ...

, notified in 1952. The Portishead Pier Section is made up of

alluvial Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. All ...

sandstones Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) b ...

which represents the best exposure of

Upper Carboniferous Upper may refer to: * Shoe upper or ''vamp'', the part of a shoe on the top of the foot * Stimulant, drugs which induce temporary improvements in either mental or physical function or both * ''Upper'', the original film title for the 2013 found f ...

rocks in the Avonmouth Coalfield. The cliff and foreshore exposures around Portishead Point provide important exposures of geological structures form during the Variscan mountain building episode ( orogeny) in the

Carboniferous Period The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

of geological history. Also included are areas which show important exposures of the Devonian sequence and yields several species of

fossil fish The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fis ...

es.

Holoptychius ''Holoptychius'' (from el, όλος , 'whole' and el, πτυχή 'fold') is an extinct genus of porolepiform lobe-finned fish from the Middle Devonian to Carboniferous ( Mississippian) periods. It is known from fossils worldwide. The genus ...

scales are the most abundant fossils, but teeth scales of other species are also relatively common. Notably amongst the collection from this bed are plates of

arthrodires Arthrodira (Greek for "jointed neck") is an order of extinct armored, jawed fishes of the class Placodermi that flourished in the Devonian period before their sudden extinction, surviving for about 50 million years and penetrating most marine ...

, including

Groenlandaspis ''Groenlandaspis'' is an extinct genus of arthrodire from the Late Devonian. Fossils of the different species are found in late Devonian strata in all continents except eastern Asia. The generic name commemorates the fact that the first specimen ...

.English Nature citation sheet for the site
(accessed 13 July 2006)

References

{{reflist Sites of Special Scientific Interest in North Somerset Sites of Special Scientific Interest notified in 1952 Portishead, Somerset