Ringdown () is a 4.0
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. ...
(9.9 acre)
biological 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 ...
west of
Burnworthy in the
Blackdown Hills
The Blackdown Hills, or Blackdowns, are a range of hills along the Somerset-Devon border in south-western England. The plateau is dominated by hard chert bands of Upper Greensand with some remnants of chalk, and is cut through by river valleys.
...
of
Somerset
Somerset ( , ), Archaism, archaically Somersetshire ( , , ) is a Ceremonial counties of England, ceremonial county in South West England. It is bordered by the Bristol Channel, Gloucestershire, and Bristol to the north, Wiltshire to the east ...
,
notified in 1990.
The site is located on a valley side in the Blackdown Hills where outcrops of both
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
Upper Greensand
Greensand or green sand is a sand or sandstone which has a greenish color. This term is specifically applied to shallow marine sediment that contains noticeable quantities of rounded greenish grains. These grains are called ''glauconies'' and co ...
and underlying
Triassic
The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...
Keuper Marls occur. Amongst the vegetation present are two species which are very restricted in South West Britain, white beaksedge (''
Rhynchospora alba'') and dioecious sedge (''
Carex dioica''). This site is the only known location for the latter in Somerset. A colony of the small pearl-bordered fritillary (''
Boloria selene'') is found here.
References
{{SSSIs Somerset biological
Sites of Special Scientific Interest in Somerset
Sites of Special Scientific Interest notified in 1990
Nature reserves in Somerset