Limestone is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of CaCO3. Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life.
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids than they are to shelled nautiloids such as the living Nautilus species. The earliest ammonites appeared during the Devonian, with the last species vanishing during or soon after the Cretaceous–Paleogene extinction event.
Portland stone is a limestone geological formation dating to the Tithonian age of the Late Jurassic that is quarried on the Isle of Portland in Dorset, England. The quarries are cut in beds of white-grey limestone separated by chert beds. It has been used extensively as a building stone throughout the British Isles, notably in major public buildings in London such as St Paul's Cathedral and Buckingham Palace. Portland stone is also exported to many countries, being used for example at the United Nations headquarters in New York City.
The geology of Great Britain is renowned for its diversity. As a result of its eventful geological history, Great Britain shows a rich variety of landscapes across the constituent countries of England, Wales and Scotland. Rocks of almost all geological ages are represented at outcrop, from the Archaean onwards.
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 pisolites. The term oolith can refer to oolite or individual ooids.
Goniatids, informally goniatites, are ammonoid cephalopods that form the order Goniatitida, derived from the more primitive Agoniatitida during the Middle Devonian some 390 million years ago. Goniatites (goniatitids) survived the Late Devonian extinction to flourish during the Carboniferous and Permian only to become extinct at the end of the Permian some 139 million years later.
Dorset is a county in South West England on the English Channel coast. Covering an area of 2,653 square kilometres (1,024 sq mi); it borders Devon to the west, Somerset to the north-west, Wiltshire to the north-east, and Hampshire to the east. The great variation in its landscape owes much to the underlying geology, which includes an almost unbroken sequence of rocks from 200 to 40 million years ago (Mya) and superficial deposits from 2 Mya to the present. In general, the oldest rocks appear in the far west of the county, with the most recent (Eocene) in the far east. Jurassic rocks also underlie the Blackmore Vale and comprise much of the coastal cliff in the west and south of the county; although younger Cretaceous rocks crown some of the highpoints in the west, they are mainly to be found in the centre and east of the county.
Clunch is a traditional building material of chalky limestone rock used mainly in eastern England and Normandy. Clunch distinguishes itself from archetypal forms of limestone by being softer in character when cut, such as resembling chalk in lower density, or with minor clay-like components.
The Lincolnshire Limestone Formation is a geological formation in England, part of the Inferior Oolite Group of the (Bajocian) Middle Jurassic strata of eastern England. It was formed around 170 million years ago, in a shallow, warm sea on the margin of the London Platform and has estuarine beds above and below it. The maximum known thickness is 40.2 metres, at around TF9730, while four kilometres further west it is 18.3 metres thick at its outcrop in the upper Witham valley. It fades out in the south, around Kettering in Northamptonshire.
The Purbeck Group is an Upper Jurassic to Lower Cretaceous lithostratigraphic group in south-east England. The name is derived from the district known as the Isle of Purbeck in Dorset where the strata are exposed in the cliffs west of Swanage.
Tuffeau stone — in French, simply tuffeau or tufeau — is a local limestone of the Loire Valley of France. It is characterized as a chalky or sandy, fine-grained limestone, white to yellowish-cream in appearance, and micaceous. The soft stone is extracted from numerous quarries and has made a major mark on the architectural landscape of the Loire and its tributaries — especially the valley's world-famous chateaux.
The Chazy Reef Formation is a mid-Ordovician limestone deposit in northeastern North America.
Monte San Giorgio is a mountain and UNESCO World Heritage Site on the border between Switzerland and Italy. It is part of the Lugano Prealps, overlooking Lake Lugano in the Swiss Canton of Ticino.
Shelly limestone is a highly fossiliferous limestone, composed of a number of fossilized organisms such as brachiopods, bryozoans, crinoids, sponges, corals and mollusks. It varies in color, texture and hardness. Coquina is a poorly indurated form of shelly limestone.
The Niobrara Formation, also called the Niobrara Chalk, is a geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the Late Cretaceous. It is composed of two structural units, the Smoky Hill Chalk Member overlying the Fort Hays Limestone Member. The chalk formed from the accumulation of coccoliths from microorganisms living in what was once the Western Interior Seaway, an inland sea that divided the continent of North America during much of the Cretaceous. It underlies much of the Great Plains of the US and Canada. Evidence of vertebrate life is common throughout the formation and includes specimens of plesiosaurs, mosasaurs, and pterosaurs as well as several primitive aquatic birds. The type locality for the Niobrara Chalk is the Niobrara River in Knox County in northeastern Nebraska. The formation gives its name to the Niobrara cycle of the Western Interior Seaway.
Pleurosternon is an extinct genus of freshwater pleurosternid turtle from the latest Jurassic to earliest Cretaceous of Europe. Its type species, P. bullockii was described by the paleontologist Richard Owen in 1853. Since then, and throughout the late 19th century, many fossil turtles were incorrectly assigned to this genus, though only two are currently considered valid.
Perryfield Quarry is an operational stone quarry and part butterfly nature reserve located on the Isle of Portland, Dorset, England. It is situated towards the middle of the island, east of the village of Weston and south of the hamlet of Wakeham. The reserve section is now a valued home for a number of butterfly species, while the working quarry area is one of the largest active quarries on Portland. The quarry is owned by Portland Stone Firms Ltd, along with Broadcroft and Coombefield Quarries. The firm is the largest landholder on the island.
Finedon Top Lodge Quarry, also known as Finedon Gullet is a 0.9-hectare (2.2-acre) geological Site of Special Scientific Interest east of Wellingborough in Northamptonshire. It is a Geological Conservation Review site revealing a sequence of middle Jurassic limestones, sandstones and ironstones, and is the type section for a sequence of sedimentary rocks known as the 'Wellingborough Member'. It was created by quarrying for the underlying ironstone for use at Wellingborough and Corby Steelworks; the ore was transported by the 1,000 mm gauge Wellingborough Tramway.
Fencepost limestone, Post Rock limestone, or Stone Post is a stone bed in the Great Plains notable for its historic use as fencing and construction material in north-central Kansas resulting in unique cultural expression. The source of this stone is the topmost layer of the Greenhorn Limestone formation. It is a regional marker bed as well as a valued construction material of the late 19th and early 20th centuries in Kansas. This stone was very suitable for early construction in treeless settlements and it adds a notable rust orange tint to the region's many historic stone buildings. But the most famous use is seen in the countless miles of stone posts lining country roads and highways. This status gives rise to such regional appellations as Stone Post Country, Post Rock Scenic Byway, and The Post Rock Capital of Kansas. This rustic quality finds Fencepost limestone still used in Kansas landscaping today.
