Portishead Pier to Black Nore SSSI
Encyclopedia
Portishead Pier to Black Nore SSSI is a 71.8 hectare
geological Site of Special Scientific Interest near the town of Portishead
in North Somerset
, notified in 1952.
The Portishead Pier Section is made up of alluvial sandstones which represents the best exposure of Upper Carboniferous 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 of geological history. Also included are areas which show important exposures of the Devonian
sequence and yields several species of fossil fishes. Holoptychius
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, including Groenlandaspis
.
Hectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
geological Site of Special Scientific Interest near the town of Portishead
Portishead, Somerset
Portishead is a coastal town on the Severn Estuary within the unitary authority of North Somerset, which falls within the ceremonial county of Somerset England. It has a population of 22,000, an increase of over 3,000 since the 2001 census, with a growth rate of 40 per cent, considerably in excess...
in North Somerset
North Somerset
North Somerset is a unitary authority in England. Its area covers part of the ceremonial county of Somerset but it is administered independently of the non-metropolitan county. Its administrative headquarters is in the town hall in Weston-super-Mare....
, notified in 1952.
The Portishead Pier Section is made up of alluvial sandstones which represents the best exposure of Upper Carboniferous 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
Orogeny
Orogeny refers to forces and events leading to a severe structural deformation of the Earth's crust due to the engagement of tectonic plates. Response to such engagement results in the formation of long tracts of highly deformed rock called orogens or orogenic belts...
) in the Carboniferous Period of geological history. Also included are areas which show important exposures of the Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
sequence and yields several species of fossil fishes. Holoptychius
Holoptychius
Holoptychius is an extinct genus of porolepiform lobe-finned fish from the Devonian period. It is known from fossils worldwide.Holoptychius was streamlined predator about long, which fed on other bony fish. Its rounded scales and body form indicate that it could have swum quickly through the water...
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, including Groenlandaspis
Groenlandaspis
Groenlandaspis is an extinct genus of armored placoderm.Groenlandaspis was a member of the Order Arthrodira, the most successful group of placoderms which also included the superpredator Dunkleosteus...
.