Barns Batch Spinney () is a 0.06-
hectare
The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), that is, square metres (), and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. ...
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 ...
near the village of
Dundry,
North Somerset
North Somerset is a unitary authorities of England, unitary authority in the ceremonial county of Somerset, England. The council is based in Weston-super-Mare, the area's largest town. The district also contains the towns of Clevedon, Nailsea ...
,
notified in 1987.
The
English Nature
English Nature was the Executive agency, United Kingdom government agency that promoted the Conservation (ethic), conservation of wildlife, geology and wild places throughout England between 1990 and 2006. It was a non-departmental public body ...
citation says that Barns Batch Spinney is important because of the exposures which it provides of the lower part of the classic Inferior
Oolite
Oolite or oölite () is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. Strictly, oolites consist of ooids of diameter 0.25–2 millimetres; rocks composed of ooids larger than 2 mm are called pis ...
limestone
Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...
sequence of the Dundry area. It shows rocks lying stratigraphically below the Middle and Upper Inferior Oolite Limestones seen at
Dundry Main Road South Quarry.
The geology at this site provides a section spanning the division of the
Middle Jurassic
The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 161.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relativel ...
known as the
Aalenian and
Bajocian
In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.9 ±0.8 Ma to around 168.2 ±1.2 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonia ...
Stages and a sequence of rocks placed in the subdivision known as the
discites zone, named after the characteristic fossil
ammonite
Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...
Hyperlioceras discites. This is one of the thickest sequences in Britain and may be used as the basis for defining these new subzones.
References
External links
Barns Batch Spinney from GCR database
{{Authority control
Bath and North East Somerset
Mendip Hills
Sites of Special Scientific Interest in Avon
Sites of Special Scientific Interest notified in 1987