A quarry is a type of open-pit mine in which dimension stone, construction aggregate, sand, gravel, or slate is excavated from the ground. The word quarry can include the underground quarrying for stone, such as Bath stone. Types of rock extracted from quarries include: Chalk China clay Cinder Clay Coal Construction aggregate Coquina Diabase Gabbro Granite Gritstone Gypsum Limestone Marble Ores Phosphate rock Quartz Sandstone Slate Many quarry stones such as marble, granite and sandstone are cut into larger slabs and removed from the quarry; the surfaces finished with varying degrees of sheen or luster. Polished slabs are cut into tiles or countertops and installed in many kinds of residential and commercial properties. Natural stone quarried from the earth is considered a luxury and tends to be a durable surface, thus desirable. Quarries in level areas with shallow groundwater or which are located close to surface water have engineering problems with drainage; the water is removed by pumping while the quarry is operational, but for high inflows more complex approaches may be required.
For example, the Coquina quarry is excavated to more than 60 feet below sea level. To reduce surface leakage, a moat lined with clay was constructed around the entire quarry. Ground water entering the pit is pumped up into the moat; as a quarry becomes deeper, water inflows increase and it becomes more expensive to lift the water higher during removal. Some water-filled quarries are worked by dredging. Many people and municipalities consider quarries to be eyesores and require various abatement methods to address problems with noise and appearance. One of the more effective and famous examples of successful quarry restoration is Butchart Gardens in Victoria, BC, Canada. A further problem is pollution of roads from trucks leaving the quarries. To control and restrain the pollution of public roads, wheel washing systems are becoming more common. Many quarries fill with water after abandonment and become lakes. Others are made into landfills. Water-filled quarries can be deep 50 ft or more, cold, so swimming in quarry lakes is not recommended.
Unexpectedly cold water can cause a swimmer's muscles to weaken. Though quarry water is very clear, submerged quarry stones and abandoned equipment make diving into these quarries dangerous. Several people drown in quarries each year. However, many inactive quarries are converted into safe swimming sites; such lakes lakes within active quarries, can provide important habitat for animals. Clay pit Coal mining Collecting fossils Gravel pit List of minerals List of rock types List of stones Miner Mountaintop removal mining Opencast mining Quarry lake Quarries
The Kent Downs is an Area of Outstanding Natural Beauty in Kent, England. They are the eastern half of the North Downs and stretch from the London/Surrey borders to the White Cliffs of Dover, it is renowned for its natural beauty. Among the named parts of the Downs are: Alkham Valley – a dry valley north-west of Dover.
In the history of Europe, the Middle Ages lasted from the 5th to the 15th century. It began with the fall of the Western Roman Empire and merged into the Renaissance and the Age of Discovery; the Middle Ages is the middle period of the three traditional divisions of Western history: classical antiquity, the medieval period, the modern period. The medieval period is itself subdivided into the Early and Late Middle Ages. Population decline, counterurbanisation, collapse of centralized authority and mass migrations of tribes, which had begun in Late Antiquity, continued in the Early Middle Ages; the large-scale movements of the Migration Period, including various Germanic peoples, formed new kingdoms in what remained of the Western Roman Empire. In the 7th century, North Africa and the Middle East—once part of the Byzantine Empire—came under the rule of the Umayyad Caliphate, an Islamic empire, after conquest by Muhammad's successors. Although there were substantial changes in society and political structures, the break with classical antiquity was not complete.
The still-sizeable Byzantine Empire, Rome's direct continuation, survived in the Eastern Mediterranean and remained a major power. The empire's law code, the Corpus Juris Civilis or "Code of Justinian", was rediscovered in Northern Italy in 1070 and became admired in the Middle Ages. In the West, most kingdoms incorporated the few extant Roman institutions. Monasteries were founded; the Franks, under the Carolingian dynasty established the Carolingian Empire during the 8th and early 9th century. It covered much of Western Europe but succumbed to the pressures of internal civil wars combined with external invasions: Vikings from the north, Magyars from the east, Saracens from the south. During the High Middle Ages, which began after 1000, the population of Europe increased as technological and agricultural innovations allowed trade to flourish and the Medieval Warm Period climate change allowed crop yields to increase. Manorialism, the organisation of peasants into villages that owed rent and labour services to the nobles, feudalism, the political structure whereby knights and lower-status nobles owed military service to their overlords in return for the right to rent from lands and manors, were two of the ways society was organised in the High Middle Ages.
The Crusades, first preached in 1095, were military attempts by Western European Christians to regain control of the Holy Land from Muslims. Kings became the heads of centralised nation-states, reducing crime and violence but making the ideal of a unified Christendom more distant. Intellectual life was marked by scholasticism, a philosophy that emphasised joining faith to reason, by the founding of universities; the theology of Thomas Aquinas, the paintings of Giotto, the poetry of Dante and Chaucer, the travels of Marco Polo, the Gothic architecture of cathedrals such as Chartres are among the outstanding achievements toward the end of this period and into the Late Middle Ages. The Late Middle Ages was marked by difficulties and calamities including famine and war, which diminished the population of Europe. Controversy and the Western Schism within the Catholic Church paralleled the interstate conflict, civil strife, peasant revolts that occurred in the kingdoms. Cultural and technological developments transformed European society, concluding the Late Middle Ages and beginning the early modern period.
The Middle Ages is one of the three major periods in the most enduring scheme for analysing European history: classical civilisation, or Antiquity. The "Middle Ages" first appears in Latin in 1469 as media tempestas or "middle season". In early usage, there were many variants, including medium aevum, or "middle age", first recorded in 1604, media saecula, or "middle ages", first recorded in 1625; the alternative term "medieval" derives from medium aevum. Medieval writers divided history into periods such as the "Six Ages" or the "Four Empires", considered their time to be the last before the end of the world; when referring to their own times, they spoke of them as being "modern". In the 1330s, the humanist and poet Petrarch referred to pre-Christian times as antiqua and to the Christian period as nova. Leonardo Bruni was the first historian to use tripartite periodisation in his History of the Florentine People, with a middle period "between the fall of the Roman Empire and the revival of city life sometime in late eleventh and twelfth centuries".
Tripartite periodisation became standard after the 17th-century German historian Christoph Cellarius divided history into three periods: ancient and modern. The most given starting point for the Middle Ages is around 500, with the date of 476 first used by Bruni. Starting dates are sometimes used in the outer parts of Europe. For Europe as a whole, 1500 is considered to be the end of the Middle Ages, but there is no universally agreed upon end date. Depending on the context, events such as the conquest of Constantinople by the Turks in 1453, Christopher Columbus's first voyage to the Americas in 1492, or the Protestant Reformation in 1517 are sometimes used. English historians use the Battle of Bosworth Field in 1485 to mark the end of the period. For Spain, dates used are the death of King Ferdinand II in 1516, the death of Queen Isabella I of Castile in 1504, or the conquest of Granada in 1492. Historians from Romance-speaking countries tend to divide the Middle Ages into two parts: an earlier "High" and late
Sandstone is a clastic sedimentary rock composed of sand-sized mineral particles or rock fragments. Most sandstone is composed of quartz or feldspar because they are the most resistant minerals to weathering processes at the Earth's surface, as seen in Bowen's reaction series. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, yellow, grey, pink and black. Since sandstone beds form visible cliffs and other topographic features, certain colors of sandstone have been identified with certain regions. Rock formations that are composed of sandstone allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Fine-grained aquifers, such as sandstones, are better able to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity. Quartz-bearing sandstone can be changed into quartzite through metamorphism related to tectonic compression within orogenic belts.
Sandstones are clastic in origin. They are formed from cemented grains that may either be fragments of a pre-existing rock or be mono-minerallic crystals; the cements binding these grains together are calcite and silica. Grain sizes in sands are defined within the range of 0.0625 mm to 2 mm. Clays and sediments with smaller grain sizes not visible with the naked eye, including siltstones and shales, are called argillaceous sediments; the formation of sandstone involves two principal stages. First, a layer or layers of sand accumulates as the result of sedimentation, either from water or from air. Sedimentation occurs by the sand settling out from suspension. Once it has accumulated, the sand becomes sandstone when it is compacted by the pressure of overlying deposits and cemented by the precipitation of minerals within the pore spaces between sand grains; the most common cementing materials are silica and calcium carbonate, which are derived either from dissolution or from alteration of the sand after it was buried.
Colors will be tan or yellow. A predominant additional colourant in the southwestern United States is iron oxide, which imparts reddish tints ranging from pink to dark red, with additional manganese imparting a purplish hue. Red sandstones are seen in the Southwest and West of Britain, as well as central Europe and Mongolia; the regularity of the latter favours use as a source for masonry, either as a primary building material or as a facing stone, over other forms of construction. The environment where it is deposited is crucial in determining the characteristics of the resulting sandstone, which, in finer detail, include its grain size and composition and, in more general detail, include the rock geometry and sedimentary structures. Principal environments of deposition may be split between terrestrial and marine, as illustrated by the following broad groupings: Terrestrial environmentsRivers Alluvial fans Glacial outwash Lakes Deserts Marine environmentsDeltas Beach and shoreface sands Tidal flats Offshore bars and sand waves Storm deposits Turbidites Framework grains are sand-sized detrital fragments that make up the bulk of a sandstone.
These grains can be classified into several different categories based on their mineral composition: Quartz framework grains are the dominant minerals in most clastic sedimentary rocks. These physical properties allow the quartz grains to survive multiple recycling events, while allowing the grains to display some degree of rounding. Quartz grains evolve from plutonic rock, which are felsic in origin and from older sandstones that have been recycled. Feldspathic framework grains are the second most abundant mineral in sandstones. Feldspar can be divided into two smaller subdivisions: plagioclase feldspars; the different types of feldspar can be distinguished under a petrographic microscope. Below is a description of the different types of feldspar. Alkali feldspar is a group of minerals in which the chemical composition of the mineral can range from KAlSi3O8 to NaAlSi3O8, this represents a complete solid solution. Plagioclase feldspar is a complex group of solid solution minerals that range in composition from NaAlSi3O8 to CaAl2Si2O8.
Lithic framework grains are pieces of ancient source rock that have yet to weather away to individual mineral grains, called lithic fragments or clasts. Lithic fragments can be any fine-grained or coarse-grained igneous, metamorphic, or sedimentary rock, although the most common lithic fragments found in sedimentary rocks are clasts of volcanic rocks. Accessory minerals are all other mineral grains in a sandstone. Common accessory minerals include micas, olivine and corundum. Many of these accessory grains are more dense than the silicates that
A gabion is a cage, cylinder, or box filled with rocks, concrete, or sometimes sand and soil for use in civil engineering, road building, military applications and landscaping. For erosion control, caged riprap is used. For dams or in foundation construction, cylindrical metal structures are used. In a military context, earth- or sand-filled gabions are used to protect sappers and artillerymen from enemy fire. Leonardo da Vinci designed a type of gabion called a Corbeille Leonard for the foundations of the San Marco Castle in Milan; the most common civil engineering use of gabions was refined and patented by Gaetano Maccaferri in the late 19th century in Sacerno, Emilia Romagna and used to stabilize shorelines, stream banks or slopes against erosion. Other uses include retaining walls, noise barriers, temporary flood walls, silt filtration from runoff, for small or temporary/permanent dams, river training, or channel lining, they may be used to direct the force of a flow of flood water around a vulnerable structure.
Gabions are used as fish screens on small streams. Gabion stepped weirs are used for river training and flood control. A gabion wall is a retaining wall made of stacked stone-filled gabions tied together with wire. Gabion walls are battered, or stepped back with the slope, rather than stacked vertically; the life expectancy of gabions depends on the lifespan of the wire, not on the contents of the basket. The structure will fail. Galvanized steel wire is most common, but PVC-coated and stainless steel wire are used. PVC-coated galvanized gabions have been estimated to survive for 60 years; some gabion manufacturers guarantee a structural consistency of 50 years. In the United States, gabion use within streams first began with projects completed from 1957 to 1965 on North River and Zealand River, New Hampshire. More than 150 grade-control structures, bank revetments and channel deflectors were constructed on the two U. S. Forest Service sites. A large portion of the in-stream structures failed due to undermining and lack of structural integrity of the baskets.
In particular and abrasion of wires by bedload movement compromised the structures, which sagged and collapsed into the channels. Other gabions were toppled into channels as trees grew and enlarged on top of gabion revetments, leveraging them toward the river channels. Gabions have been used in building, as in the Dominus Winery in the Napa Valley, California, by architects Herzog & de Meuron, constructed between 1995 and 1997; the exterior is formed by modular wire mesh gabions containing locally quarried stone. There are various special designs of gabions to meet particular functional requirements and some special terms for particular forms have come into use. For example: Bastion: a gabion lined internally with a membrane of nonwoven geotextile to permit use of a granular soil fill, instead of rock. Mattress: a form of gabion with small height relative to the lateral dimensions. For protecting surfaces from wave erosion and similar attack, rather than building or supporting high structures.
Trapion: a form of gabion with a trapezoidal cross section, designed for stacking to give a face, sloping rather than stepped. The term is in wide usage, but in contexts related to gabions at least, appears to be a trademark registered by Betafence Limited. Early gabions were round cages with open tops and bottoms, made from wickerwork and filled with earth for use as military fortifications; these early military gabions were most used to protect sappers and siege artillery gunners. The wickerwork cylinders were light and could be carried conveniently in the ammunition train if they were made in several diameters to fit one inside another. At the site of use in the field, they could be stood on end, staked in position, filled with soil to form an effective wall around the gun, or construct a bulletproof parapet along a sap. During the Crimean War, local shortages of brushwood led to use of scrap hoop-iron from hay bales in its stead. Today, gabions are used to protect forward operating bases against explosive, indirect fires such as mortar or artillery fire.
Examples of areas within a FOB that make extensive use of gabions are sleeping quarters, mess halls, or any place where there would be a large concentration of unprotected soldiers. Gabions are used for aircraft revetments, blast walls, similar structures. Cellular confinement, a small-scale mattress gabion used for roads, retaining walls, protective structures. Hesco bastion, a modernized version of the same concept Maccaferri gabion, wire mesh gabions introduced into modern civil engineering Stepped spillway
The public domain consists of all the creative works to which no exclusive intellectual property rights apply. Those rights may have been forfeited, expressly waived, or may be inapplicable; the works of William Shakespeare and Beethoven, most early silent films, are in the public domain either by virtue of their having been created before copyright existed, or by their copyright term having expired. Some works are not covered by copyright, are therefore in the public domain—among them the formulae of Newtonian physics, cooking recipes, all computer software created prior to 1974. Other works are dedicated by their authors to the public domain; the term public domain is not applied to situations where the creator of a work retains residual rights, in which case use of the work is referred to as "under license" or "with permission". As rights vary by country and jurisdiction, a work may be subject to rights in one country and be in the public domain in another; some rights depend on registrations on a country-by-country basis, the absence of registration in a particular country, if required, gives rise to public-domain status for a work in that country.
The term public domain may be interchangeably used with other imprecise or undefined terms such as the "public sphere" or "commons", including concepts such as the "commons of the mind", the "intellectual commons", the "information commons". Although the term "domain" did not come into use until the mid-18th century, the concept "can be traced back to the ancient Roman Law, as a preset system included in the property right system." The Romans had a large proprietary rights system where they defined "many things that cannot be owned" as res nullius, res communes, res publicae and res universitatis. The term res nullius was defined as things not yet appropriated; the term res communes was defined as "things that could be enjoyed by mankind, such as air and ocean." The term res publicae referred to things that were shared by all citizens, the term res universitatis meant things that were owned by the municipalities of Rome. When looking at it from a historical perspective, one could say the construction of the idea of "public domain" sprouted from the concepts of res communes, res publicae, res universitatis in early Roman law.
When the first early copyright law was first established in Britain with the Statute of Anne in 1710, public domain did not appear. However, similar concepts were developed by French jurists in the 18th century. Instead of "public domain", they used terms such as publici juris or propriété publique to describe works that were not covered by copyright law; the phrase "fall in the public domain" can be traced to mid-19th century France to describe the end of copyright term. The French poet Alfred de Vigny equated the expiration of copyright with a work falling "into the sink hole of public domain" and if the public domain receives any attention from intellectual property lawyers it is still treated as little more than that, left when intellectual property rights, such as copyright and trademarks, expire or are abandoned. In this historical context Paul Torremans describes copyright as a, "little coral reef of private right jutting up from the ocean of the public domain." Copyright law differs by country, the American legal scholar Pamela Samuelson has described the public domain as being "different sizes at different times in different countries".
Definitions of the boundaries of the public domain in relation to copyright, or intellectual property more regard the public domain as a negative space. According to James Boyle this definition underlines common usage of the term public domain and equates the public domain to public property and works in copyright to private property. However, the usage of the term public domain can be more granular, including for example uses of works in copyright permitted by copyright exceptions; such a definition regards work in copyright as private property subject to fair-use rights and limitation on ownership. A conceptual definition comes from Lange, who focused on what the public domain should be: "it should be a place of sanctuary for individual creative expression, a sanctuary conferring affirmative protection against the forces of private appropriation that threatened such expression". Patterson and Lindberg described the public domain not as a "territory", but rather as a concept: "here are certain materials – the air we breathe, rain, life, thoughts, ideas, numbers – not subject to private ownership.
The materials that compose our cultural heritage must be free for all living to use no less than matter necessary for biological survival." The term public domain may be interchangeably used with other imprecise or undefined terms such as the "public sphere" or "commons", including concepts such as the "commons of the mind", the "intellectual commons", the "information commons". A public-domain book is a book with no copyright, a book, created without a license, or a book where its copyrights expired or have been forfeited. In most countries the term of protection of copyright lasts until January first, 70 years after the death of the latest living author; the longest copyright term is in Mexico, which has life plus 100 years for all deaths since July 1928. A notable exception is the United States, where every book and tale published prior to 1924 is in the public domain.
Slate is a fine-grained, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. It is the finest grained foliated metamorphic rock. Foliation may not correspond to the original sedimentary layering, but instead is in planes perpendicular to the direction of metamorphic compression; the foliation in slate is called "slaty cleavage". It is caused by strong compression causing fine grained clay flakes to regrow in planes perpendicular to the compression; when expertly "cut" by striking parallel to the foliation, with a specialized tool in the quarry, many slates will display a property called fissility, forming smooth flat sheets of stone which have long been used for roofing, floor tiles, other purposes. Slate is grey in color when seen, en masse, covering roofs. However, slate occurs in a variety of colors from a single locality. Slate is not to schist; the word "slate" is used for certain types of object made from slate rock.
It may mean a writing slate. They were traditionally a small, smooth piece of the rock framed in wood, used with chalk as a notepad or noticeboard, for recording charges in pubs and inns; the phrases "clean slate" and "blank slate" come from this usage. Before the mid-19th century, the terms slate and schist were not distinguished. In the context of underground coal mining in the United States, the term slate was used to refer to shale well into the 20th century. For example, roof slate referred to shale above a coal seam, draw slate referred to shale that fell from the mine roof as the coal was removed. Slate is composed of the minerals quartz and muscovite or illite along with biotite, chlorite and pyrite and, less apatite, kaolinite, tourmaline, or zircon as well as feldspar; as in the purple slates of North Wales, ferrous reduction spheres form around iron nuclei, leaving a light green spotted texture. These spheres are sometimes deformed by a subsequent applied stress field to ovoids, which appear as ellipses when viewed on a cleavage plane of the specimen.
Slate can be made into roofing slates, a type of roof shingle, or more a type of roof tile, which are installed by a slater. Slate has two lines of breakability – cleavage and grain – which make it possible to split the stone into thin sheets; when broken, slate retains a natural appearance while remaining flat and easy to stack. A "slate boom" occurred in Europe from the 1870s until the first world war, allowed by the use of the steam engine in manufacturing slate tiles and improvements in road and waterway transportation systems. Slate is suitable as a roofing material as it has an low water absorption index of less than 0.4%, making the material waterproof. In fact, this natural slate, which requires only minimal processing, has the lowest embodied energy of all roofing materials. Natural slate is used by building professionals as a result of its durability. Slate is durable and can last several hundred years with little or no maintenance, its low water absorption makes it resistant to frost damage and breakage due to freezing.
Natural slate is fire resistant and energy efficient. Slate roof tiles are fixed either with nails, or with hooks as is common with Spanish slate. In the UK, fixing is with double nails onto timber battens or nailed directly onto timber sarking boards. Nails were traditionally of copper, although there are modern alloy and stainless steel alternatives. Both these methods, if used properly, provide a long-lasting weathertight roof with a lifespan of around 80–100 years; some mainland European slate suppliers suggest that using hook fixing means that: Areas of weakness on the tile are fewer since no holes have to be drilled Roofing features such as valleys and domes are easier to create since narrow tiles can be used Hook fixing is suitable in regions subject to severe weather conditions, since there is greater resistance to wind uplift, as the lower edge of the slate is secured. The metal hooks are, however and may be unsuitable for historic properties. Slate tiles are used for interior and exterior flooring, stairs and wall cladding.
Tiles are grouted along the edges. Chemical sealants are used on tiles to improve durability and appearance, increase stain resistance, reduce efflorescence, increase or reduce surface smoothness. Tiles are sold gauged, meaning that the back surface is ground for ease of installation. Slate flooring can be slippery. Slate tiles were used in 19th century UK building construction and in slate quarrying areas such as Blaenau Ffestiniog and Bethesda, Wales there are still many buildings wholly constructed of slate. Slates can be set into walls to provide a rudimentary damp-proof membrane. Small offcuts are used as shims to level floor joists. In areas where slate is plentiful it is used in pieces of various sizes for building walls and hedges, sometimes combined with other kinds of stone. In modern homes slate is used as table coasters; because it is a good electrical insulator and fireproof, it was used to construct early-20th-century electric switchboards and relay controls for large electric motors.
Fine slate can be used as a whe