Misplaced Pages

#750249

16-600: Reigate Stone is a freestone that was mined from the Upper Greensand in north east Surrey . It was used in building work throughout the Middle Ages and early modern period . It is sometimes classified as a calcareous sandstone , although very little of the silica content is in the form of detrital sand grains . In addition to silicon dioxide, the stone also includes clay , fine-grained calcite , mica flakes and glauconite . Since exposure of Upper Greensand

32-444: A 'seed', such as a piece of a shell. Strong intertidal currents wash the 'seeds' around on the seabed, where they accumulate layers of chemically precipitated calcite from the supersaturated water. The oolites are commonly found in large current bedding structures that resemble sand dunes. The size of the oolites reflect the time that they were exposed to the water before they were covered with later sediment. Oolites are often used in

48-837: A lot of surface area, which promotes high bacterial growth. Some exemplar oolitic limestone was formed in England during the Jurassic period, and forms the Cotswold Hills , the Isle of Portland with its famous Portland Stone , and part of the North York Moors . A particular type, Bath Stone , gives the buildings of the World Heritage City of Bath their distinctive appearance. Carboniferous Hunts Bay Oolite lies under much of south Wales . The Miami Rock Ridge of southeastern Florida,

64-406: Is a type of stone used in masonry for molding , tracery and other replication work required to be worked with the chisel . Freestone, so named because it can be freely cut in any direction, must be fine-grained, uniform and soft enough to be cut easily without shattering or splitting. Some sources, including numerous nineteenth-century dictionaries, say that the stone has no grain, but this

80-941: Is also found in Indiana in the United States . The town of Oolitic, Indiana , was founded for the trade in limestone and bears its name. Quarries in Oolitic, Bedford , and Bloomington contributed the materials for such U.S. landmarks as the Empire State Building in New York and the Pentagon in Arlington, Virginia . Many of the buildings on the Indiana University campus in Bloomington are built with native oolitic limestone material, and

96-754: Is in the foundations of Edward the Confessor 's monastery at Westminster in the first half of the 11th century, although archaeological evidence from St Mary's Church, Stoke d'Abernon suggests that it was being quarried by the early eighth century. The stone is found in numerous medieval buildings in London , including the White Tower of the Tower of London , and Hampton Court Palace , as well as other important buildings in south east England such as Waltham Abbey , Windsor Castle and both Rochester and Canterbury Cathedrals . It

112-601: Is incorrect. Oolitic stones are generally used, although in some countries soft sandstones are used; in some churches an indurated chalk called clunch is employed for internal lining and for carving . Some have believed that the word " freemason " originally referred, from the 14th century, to a person capable of carving freestone. Oolite Ooids are most commonly composed of calcium carbonate ( calcite or aragonite ), but can be composed of phosphate, clays, chert , dolomite or iron minerals, including hematite . Dolomitic and chert ooids are most likely

128-426: Is rare, Reigate Stone was generally extracted from underground workings, although it may have been quarried from the surface at first. The stone was mined using the post-and-stall technique, in which adits (approximately 4 m (13 ft) wide and 1.5 m (5 ft) high) were cut into the beds, which dip downwards below the chalk above. Parallel grooves in the floors of these workings suggest that cut stone

144-487: The Great Fire of London . Wren was particularly concerned to make sure that the stone was properly sourced, having identified its susceptibility to frost damage . In later centuries, Reigate Stone appears to have been particularly vulnerable to damage by pollution . The final mine closed in the 1960s, although fresh stone was procured for a new stairwell at Westminster Abbey in 2018. Freestone (masonry) A freestone

160-492: The Plain formed the bed of Lake Idaho . Wave action in the lake washed sediments back and forth in the shallows on the southwestern shore, forming ooids and depositing them on steeper benches near the shore in 2- to 40-foot thicknesses. When the lake drained (2 to 4 million years ago), the oolite was left behind, along with siltstone , volcanic tuffs and alluvium from adjacent mountain slopes. The other sediments eroded away, while

176-470: The home aquarium industry because their small grain size (0.2 to 1.22 mm) is ideal for shallow static beds and bottom covering of up to 1" in depth. Also known as "oolitic" sand, the sugar-sized round grains of this sand pass easily through the gills of gobies and other sand-sifting organisms. This unusually smooth sand promotes the growth of bacteria, which are important biofilters in home aquaria. Because of its extremely small grain size, oolitic sand has

SECTION 10

#1732844234751

192-720: The islands of the Lower Florida Keys , and much of the Everglades , are underlain by Miami Oolite . This limestone was formed by deposition when shallow seas covered the area between periods of glaciation . The material consolidated and eroded during later exposure above the ocean surface. One of the world's largest freshwater lakebed oolites is the Shoofly Oolite, a section of the Glenns Ferry Formation on southwestern Idaho 's Snake River Plain . 10 million years ago,

208-510: The more resistant oolite weathered into hummocks, small arches and other natural "sculptures". The Shoofly Oolite lies on public land west of Bruneau, Idaho managed by the Bureau of Land Management (BLM). The physical and chemical properties of the Shoofly Oolite are the setting for a suite of rare plants, which the BLM protects through land use management and on-site interpretation. This type of limestone

224-399: The result of the replacement of the original texture in limestone. Oolitic hematite occurs at Red Mountain near Birmingham, Alabama , along with oolitic limestone. They are usually formed in warm, supersaturated, shallow, highly agitated marine water intertidal environments, though some are formed in inland lakes. The mechanism of formation starts with a small fragment of sediment acting as

240-513: Was brought to the surface on wooden sledges . Mines are thought to have existed along the base of the North Downs from Buckland in the west to Chaldon in the east. Many probable sites were most likely destroyed by the construction of the M25 motorway , although the earliest recorded mine has been identified at the foot of Colley Hill to the north of Reigate . The first recorded use of Reigate Stone

256-608: Was used increasingly in place of Caen stone , especially after the loss of the Duchy of Normandy by King John in 1204. In the Tudor period , Reigate Stone was used in the construction of Nonsuch Palace , although much of it came from the demolition of Merton Priory and only a small portion was freshly mined. The stone continued to be used in the 17th century, including by Christopher Wren in St Paul's Cathedral and other city churches, following

#750249