The Coniston Group is a
Silurian
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago (Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoi ...
lithostratigraphic
Lithostratigraphy is a sub-discipline of stratigraphy, the geological science associated with the study of strata or rock layers. Major focuses include geochronology, comparative geology, and petrology.
In general, strata are primarily igneous ...
group (a sequence of
rock strata
In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...
) in the southern
Lake District and north-west
Pennines
The Pennines (), also known as the Pennine Chain or Pennine Hills, are a range of uplands running between three regions of Northern England: North West England on the west, North East England and Yorkshire and the Humber on the east. Commonly ...
of northern
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...
. The name is derived from the small town of
Coniston in
Cumbria
Cumbria ( ) is a ceremonial and non-metropolitan county in North West England, bordering Scotland. The county and Cumbria County Council, its local government, came into existence in 1974 after the passage of the Local Government Act 1972. ...
. The rocks of the Group have also previously been referred to as the Coniston Grits or Coniston Grits Formation and Coniston Subgroup. The group comprises
sandstone
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 ...
s and
siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, ...
s and some laminated
hemipelagites which achieve a thickness of between 1400 and 1900m. Overlain by the Bannisdale Formation of the
Kendal Group and underlain by the Wray Castle Formation of the
Tranearth Group, it is divided into several formations. These are, in ascending order (oldest first): Wray Castle, Gawthwaite, Latrigg, Poolscar, Moorhow (or Moorhowe) and Yewbank.
References
*
Silurian System of Europe
Geology of England
Geological groups of the United Kingdom
Geologic formations of the United Kingdom
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