The Much Wenlock Limestone Formation is a series of
Silurian
The Silurian ( ) is a geologic period and system spanning 23.5 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 third and shortest period of t ...
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) ...
beds that date back to the
Homerian age, the later part of the
Wenlock epoch.
[{{cite web , url=http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=WEL , title=Much Wenlock Limestone Formation , publisher=]British Geological Survey
The British Geological Survey (BGS) is a partly publicly funded body which aims to advance Earth science, geoscientific knowledge of the United Kingdom landmass and its continental shelf by means of systematic surveying, monitoring and research. ...
, work=The BGS Lexicon of Named Rock Units , date=2013 , accessdate=11 July 2013 The formation comprises nodular to thinly bedded limestones, with variable development of
reef
A reef is a ridge or shoal of rock, coral, or similar relatively stable material lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic (non-living) processes such as deposition (geol ...
bodies that can be found exposed at
Wenlock Edge
Wenlock Edge is a limestone escarpment near Much Wenlock, Shropshire, England and a site of special scientific interest because of its geology. It is over long, running southwest to northeast between Craven Arms and Much Wenlock, and is roughly ...
and in a small area near
Dudley
Dudley ( , ) is a market town in the West Midlands, England, southeast of Wolverhampton and northwest of Birmingham. Historically part of Worcestershire, the town is the administrative centre of the Metropolitan Borough of Dudley. In the ...
,
England
England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...
known as
Wren's Nest. The formation is made up of three different members which have been classified as the Lower Quarried Limestone Member, the Nodular Beds Member and the Upper Quarried Limestone Member.
[Dorning, K. J. 1983. Palynology and stratigraphy of the Much Wenlock Limestone Formation, Dudley, Central England. Mercian Geologist, 20, 31-40.] Many of the members can be subdivided into separate
lithofacies that would have been deposited under different environmental conditions. However the overall environment of deposition for the formation is in a shallow, tropical marine setting that is located between the storm
wave base
The wave base, in physical oceanography, is the maximum depth at which a water wave's passage causes significant water motion. At water depths deeper than the wave base, bottom sediments and the seafloor are no longer stirred by the wave motion ...
and the fair weather wave base.
References
Geology of Shropshire
Homerian
Silurian southern paleotemperate deposits