Quartzite is a hard, non-foliated metamorphic rock, pure quartz sandstone. Sandstone is converted into quartzite through heating and pressure related to tectonic compression within orogenic belts. Pure quartzite is white to grey, though quartzites occur in various shades of pink and red due to varying amounts of iron oxide. Other colors, such as yellow, green and orange, are due to other minerals; when sandstone is cemented to quartzite, the individual quartz grains recrystallize along with the former cementing material to form an interlocking mosaic of quartz crystals. Most or all of the original texture and sedimentary structures of the sandstone are erased by the metamorphism; the grainy, sandpaper-like surface becomes glassy in appearance. Minor amounts of former cementing materials, iron oxide, silica and clay migrate during recrystallization and metamorphosis; this causes lenses to form within the quartzite. Orthoquartzite is a pure quartz sandstone composed of well-rounded quartz grains cemented by silica.
Orthoquartzite is 99% SiO2 with only minor amounts of iron oxide and trace resistant minerals such as zircon and magnetite. Although few fossils are present, the original texture and sedimentary structures are preserved; the term is traditionally used for quartz-cemented quartz arenites, both usages are found in the literature. The typical distinction between the two is a metamorphic quartzite is so cemented, diagenetically altered, metamorphosized so that it will fracture and break across grain boundaries, not around them. Quartzite is resistant to chemical weathering and forms ridges and resistant hilltops; the nearly pure silica content of the rock provides little material for soil. In the United States, formations of quartzite can be found in some parts of Pennsylvania, the Washington DC area, eastern South Dakota, Central Texas, southwest Minnesota, Devil's Lake State Park in the Baraboo Range in Wisconsin, the Wasatch Range in Utah, near Salt Lake City, Utah and as resistant ridges in the Appalachians and other mountain regions.
Quartzite is found in the Morenci Copper Mine in Arizona. The town of Quartzsite in western Arizona derives its name from the quartzites in the nearby mountains in both Arizona and Southeastern California. A glassy vitreous quartzite has been described from the Belt Supergroup in the Coeur d’Alene district of northern Idaho. In the United Kingdom, a craggy ridge of quartzite called the Stiperstones runs parallel with the Pontesford-Linley fault, 6 km north-west of the Long Mynd in south Shropshire. To be found in England are the Cambrian "Wrekin quartzite", the Cambrian "Hartshill quartzite". In Wales, Holyhead mountain and most of Holy island off Anglesey sport excellent Precambrian quartzite crags and cliffs. In the Scottish Highlands, several mountains composed of Cambrian quartzite can be found in the far north-west Moine Thrust Belt running in a narrow band from Loch Eriboll in a south-westerly direction to Skye. In Ireland areas of quartzite are found across the northwest, with Errigal in Donegal as the most prominent outcrop.
In continental Europe, various regionally isolated quartzite deposits exist at surface level in a belt from the Rhenish Massif and the German Central Highlands into the Western Czech Republic, for example in the Taunus and Harz mountains. In Poland quartzite deposits at surface level exists in Świętokrzyskie Mountains. In Canada, the La Cloche Mountains in Ontario are composed of white quartzite; the highest mountain in Mozambique, Monte Binga, as well as the rest of the surrounding Chimanimani Plateau are composed of hard, pale grey, Precambrian quartzite. Quartzite is mined in Brazil for use in kitchen countertops; because of its hardness and angular shape, crushed quartzite is used as railway ballast. Quartzite is a decorative stone and may be used to cover walls, as roofing tiles, as flooring, stair steps, its use for countertops in kitchens is expanding rapidly. It is more resistant to stains than granite. Crushed quartzite is sometimes used in road construction. High purity quartzite is used to produce ferrosilicon, industrial silica sand and silicon carbide.
During the Paleolithic, quartzite was used, along with flint and other lithic raw materials, for making stone tools. The term quartzite is derived from German: Quarzit. Neomorphism R. V. Dietrich's GemRocks: Quartzite CSU Pomona Geology: Quartzite Cowen's "The First Geologists" Minnesota Department of Natural Resources: Natural History: Minnesota's geology Wisconsin's Baraboo Syncline South Dakota 2002 Mineral Summary: Production and Environmental Issues Big Sioux River: History of Sioux Falls and Quartzite Photos
Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.063 millimetres with individual grains too small to be distinguished without a microscope. With increased pressure over time, the platy clay minerals may become aligned, with the appearance of fissility or parallel layering; this finely bedded material that splits into thin layers is called shale, as distinct from mudstone. The lack of fissility or layering in mudstone may be due to either original texture or the disruption of layering by burrowing organisms in the sediment prior to lithification. Mud rocks such as mudstone and shale account for some 65% of all sedimentary rocks. Mudstone looks like hardened clay and, depending upon the circumstances under which it was formed, it may show cracks or fissures, like a sun-baked clay deposit. Mudstone can be separated into these categories: Siltstone — more than half of the composition is silt-sized particles. Claystone — more than half of the composition is clay-sized particles.
Mudstone — hardened mud. Mudstone can include: Shale -- exhibits fissility. Argillite — has undergone low-grade metamorphism. In the Dunham classification system of limestones, a mudstone is defined as a mud-supported carbonate rock that contains less than 10% grains. Most this definition has been clarified as a matrix-supported carbonate-dominated rock composed of more than 90% carbonate mud component. A recent study by Lokier and Al Junaibi has highlighted that the most common problems encountered when describing a mudstone is to incorrectly estimate the volume of'grains' in the sample - in consequence, misidentifying mudstone as wackestone and vice versa; the original Dunham classification defined the matrix as clay and fine-silt size sediment <20 μm in diameter. This definition was redefined by Embry & Klovan to a grain size of less than or equal to 30 μm. Wright proposed a further increase to the upper limit for the matrix size in order to bring it into line with the upper limit for silt.
On December 13, 2016, NASA reported further evidence supporting habitability on the planet Mars as the Curiosity rover climbed higher, studying younger layers, on Mount Sharp. Reported, the soluble element boron was detected for the first time on Mars. In June 2018, NASA reported that Curiosity had detected kerogen and other complex organic compounds from mudstone rocks 3.5 billion years old. Mudstone on planet Mars Aeolis quadrangle Composition of Mars Timeline of Mars Science Laboratory Tonstein – A hard, compact sedimentary rock, composed of kaolinite or, less other clay minerals
Piedmont (United States)
The Piedmont is a plateau region located in the Eastern United States. It sits between the Atlantic coastal plain and the main Appalachian Mountains, stretching from New Jersey in the north to central Alabama in the south; the Piedmont Province is a physiographic province of the larger Appalachian division which consists of the Gettysburg-Newark Lowlands, the Piedmont Upland and the Piedmont Lowlands sections. The Atlantic Seaboard fall line marks the Piedmont's eastern boundary with the Coastal Plain. To the west, it is bounded by the Blue Ridge Mountains, the easternmost range of the main Appalachians; the width of the Piedmont varies, being quite narrow above the Delaware River but nearly 300 miles wide in North Carolina. The Piedmont's area is 80,000 square miles; the name "Piedmont" comes from the French term for the same physical region meaning "foothill" from Latin "pedemontium", meaning "at the foot of the mountains", similar to the name of the Italian region of Piedmont, abutting the Alps.
The surface relief of the Piedmont is characterized by low, rolling hills with heights above sea level between 200 feet and 800 feet to 1,000 feet. Its geology is complex, with numerous rock formations of different materials and ages intermingled with one another; the Piedmont is the remnant of several ancient mountain chains that have since been eroded away. Geologists have identified at least five separate events which have led to sediment deposition, including the Grenville orogeny and the Appalachian orogeny during the formation of Pangaea; the last major event in the history of the Piedmont was the break-up of Pangaea, when North America and Africa began to separate. Large basins formed from the rifting and were subsequently filled by the sediments shed from the surrounding higher ground; the series of Mesozoic basins is entirely located inside the Piedmont region. Piedmont soils are clay-like and moderately fertile. In some areas they have suffered from erosion and over-cropping in the South where cotton was the chief crop.
In the central Piedmont region of North Carolina and Virginia, tobacco is the main crop, while in the north region there is more diversity, including orchards and general farming. The portion of the Piedmont region in the southern United States, is associated with the Piedmont blues, a style of blues music that originated there in the late 19th century. According to the Piedmont Blues Preservation Society, most Piedmont blues musicians came from Virginia, the Carolinas, Georgia. During the Great Migration, African Americans migrated to the Piedmont. With the Appalachian Mountains to the west, those who might otherwise have spread into rural areas stayed in cities and were thus exposed to a broader mixture of music than those in, for example, the rural Mississippi delta. Thus, Piedmont blues was influenced by many types of music such as ragtime and popular songs—styles that had comparatively less influence on blues music in other regions. Many major cities are located on the Atlantic Seaboard fall line, the eastern boundary of the Piedmont.
The fall line, where the land rises abruptly from the coastal plain, marks the limit of navigability on many major rivers, so inland ports sprang up along it. Within the Piedmont region itself, there are several areas of urban concentration, the largest being the Philadelphia metropolitan area in Pennsylvania; the Piedmont cuts Maryland in half. In Virginia, the Greater Richmond metropolitan area is the largest urban concentration. In North Carolina, the Piedmont Crescent includes several metropolitan clusters such as Charlotte metropolitan area, the Piedmont Triad, the Research Triangle. Other notable areas include the Greenville-Spartanburg-Anderson, SC Combined Statistical Area in South Carolina, in Georgia, the Atlanta metropolitan area. Cecil Piedmont Atlantic Piedmont region of Virginia Interstate 85 Godfrey, Michael A.. Field Guide to the Piedmont. Chapel Hill: University of North Carolina Press. ISBN 0-8078-4671-6. Hilton Pond Center for Piedmont Natural History "Piedmont Plain". New International Encyclopedia.
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
Limestone is a carbonate sedimentary rock, composed of the skeletal fragments of marine organisms such as coral and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate. A related rock is dolostone, which contains a high percentage of the mineral dolomite, CaMg2. In fact, in old USGS publications, dolostone was referred to as magnesian limestone, a term now reserved for magnesium-deficient dolostones or magnesium-rich limestones. About 10% of sedimentary rocks are limestones; the solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. Limestone has numerous uses: as a building material, an essential component of concrete, as aggregate for the base of roads, as white pigment or filler in products such as toothpaste or paints, as a chemical feedstock for the production of lime, as a soil conditioner, or as a popular decorative addition to rock gardens.
Like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of marine organisms such as foraminifera; these organisms secrete shells made of aragonite or calcite, leave these shells behind when they die. Other carbonate grains composing limestones are ooids, peloids and extraclasts. Limestone contains variable amounts of silica in the form of chert or siliceous skeletal fragment, varying amounts of clay and sand carried in by rivers; some limestones do not consist of grains, are formed by the chemical precipitation of calcite or aragonite, i.e. travertine. Secondary calcite may be deposited by supersaturated meteoric waters; this produces speleothems, such as stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance; the primary source of the calcite in limestone is most marine organisms. Some of these organisms can construct mounds of rock building upon past generations. Below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone does not form in deeper waters.
Limestones may form in lacustrine and evaporite depositional environments. Calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, dissolved ion concentrations. Calcite exhibits an unusual characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors with weathered surfaces. Limestone may be crystalline, granular, or massive, depending on the method of formation. Crystals of calcite, dolomite or barite may line small cavities in the rock; when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams where there are waterfalls and around hot or cold springs. Calcium carbonate is deposited where evaporation of the water leaves a solution supersaturated with the chemical constituents of calcite.
Tufa, a porous or cellular variety of travertine, is found near waterfalls. Coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the mountain building process, limestone recrystallizes into marble. Limestone is a parent material of Mollisol soil group. Two major classification schemes, the Folk and the Dunham, are used for identifying the types of carbonate rocks collectively known as limestone. Robert L. Folk developed a classification system that places primary emphasis on the detailed composition of grains and interstitial material in carbonate rocks. Based on composition, there are three main components: allochems and cement; the Folk system uses two-part names. It is helpful to have a petrographic microscope when using the Folk scheme, because it is easier to determine the components present in each sample; the Dunham scheme focuses on depositional textures. Each name is based upon the texture of the grains. Robert J. Dunham published his system for limestone in 1962.
Dunham divides the rocks into four main groups based on relative proportions of coarser clastic particles. Dunham names are for rock families, his efforts deal with the question of whether or not the grains were in mutual contact, therefore self-supporting, or whether the rock is characterized by the presence of frame builders and algal mats. Unlike the Folk scheme, Dunham deals with the original porosity of the rock; the Dunham scheme is more useful for hand samples because it is based on texture, not the grains in the sample. A revised classification was proposed by Wright, it adds some diagenetic patterns and can be summarized as follows: See: Carbonate platform About 10% of all sedimentary rocks are limestones. Limestone is soluble in acid, therefore forms many erosional landforms; these include limestone pavements, pot holes, cenotes and gorges. Such erosion landscapes are known
Brasstown Bald is the highest point in the U. S. state of Georgia. Located in northeast Georgia, the mountain is known to the native Cherokee people as Enotah, it is the highest ground for 15.86 miles. The name in English is derived from a mistaken translation of the term for the nearby Cherokee village of Brasstown, located along the upper Brasstown Creek feeding the Hiawassee River. Across the North Carolina state line north of the mountain, are other places named in that error of English settlers: Brasstown, a community in the Brasstown township of Clay County, North Carolina. Brasstown Bald is in both Towns and Union counties, the peak being divided by the county line; the mountain is part of the Blue Ridge Mountains, within the borders of the Blue Ridge Ranger District of the Chattahoochee National Forest. The mountain consists of soapstone and dunite. On a clear day, it is possible to see the tall buildings of Atlanta from the summit; the U. S. Forest Service has webcams atop the observation tower, a RAWS weather station further down the mountain.
The public can drive to the top via Georgia State Route 180 Spur. According to the two Georgia historical markers, the area surrounding Brasstown Bald was settled by the Cherokee people. English-speaking settlers derived the word "Brasstown" from a translation error of the Cherokee word for its village place. Settlers confused the word Itse'yĭ, which the Cherokee used for their village, with Ûňtsaiyĭ, referred to the settlement as Brasstown; the Cherokee gave the locative name, Itse'yĭ, to several distinct areas in their territory, including an area nearby in what is considered present-day North Carolina. According to Cherokee legend about Itse'yĭ, a great flood swept over the land. All the people died except a few Cherokee families; the canoe ran aground at the summit of a forested mountain. As there was no wild game for the people to hunt and no place for them to plant crops, the Great Spirit killed all the trees on the top of the mountain so that the surviving people could plant crops, they lived from their crops until the water subsided.
Other transliterated spellings of the Cherokee name for the mountain include Echia, Echoee and Enotah. The term "Bald" is common terminology in the southern Appalachians describing mountaintops that have 360-degree unobstructed views. Former Georgia Supreme Court Judge Thomas S. Candler is memorialized with a stone monument at Brasstown Bald, it was erected in 1971 three months before he died in recognition of his efforts to support getting more visitors to the mountain and establishing a visitors center there for them. From the northeast, starting at the intersection of Owl Creek Road and the concurrent Georgia 17 and Georgia 75 near Mountain Scene, the climb is 13.5 kilometers long, gaining 828 meters. From the southeast, starting at the intersection of Georgia 180 and Georgia 17/75 near Sooky Gap, the climb is 13.1 kilometers long, gaining 790 meters, an average of 6.0% grade. From the west, starting at the intersection of Georgia 180 and Georgia 348 near Choestoe, the climb is 14.9 kilometers, gaining 856 meters, an average of 5.7% grade.
From the intersection of Route 180 and Route 180 Spur at Jacks Gap the climb is 4.9 kilometers at an average gradient of 11.2%. An additional route to the summit is the Wagon Train Trail, starting at Young Harris College; the trail is traditionally hiked by graduating students and their families on the evening before graduation. In the 2005 through 2008 editions of the Tour de Georgia, a long-distance bicycle race, Brasstown Bald was the site of an hors categorie "King of the Mountains stage" finish. NOAA Weather Radio station KXI22 transmits from atop the mountain, simulcasting with KXI75 from Blue Ridge, Georgia; the programming originates from NWSFO Peachtree City. Georgia Public Broadcasting had or has construction permits from the Federal Communications Commission for two low-power broadcast translator stations at the summit; the digital TV station on channel 12 is the direct replacement for analog TV station W04BJ in nearby Young Harris, covers for W50AB in nearby Hiawassee. New station WBTB FM 90.3 will transmit at just 97 watts, equivalent to several hundred watts because of the height above average terrain of over 700 meters, or more than 2,300 feet.
Both stations will have Young Harris as the city of license. Brasstown Valley Resort Brasstown Wilderness List of U. S. states by elevation List of mountains in Georgia Media related to Brasstown Bald at Wikimedia Commons
The Ridge-and-Valley Appalachians called the Ridge and Valley Province or the Valley and Ridge Appalachians, are a physiographic province of the larger Appalachian division and are a belt within the Appalachian Mountains extending from southeastern New York through northwestern New Jersey, westward into Pennsylvania and southward into Maryland, West Virginia, Kentucky, Tennessee and Alabama. They form a broad arc between the Blue Ridge Mountains and the Appalachian Plateau physiographic province, they are characterized by long ridges, with long, continuous valleys in between. The ridge and valley system presents an important obstacle to east–west land travel with today's technology, it was a nearly insurmountable barrier to railroads crossing the range as well as to walking or horse-riding migrants traveling west to settle the Ohio Country, Northwest Territory and Oregon Country, before the days of motorized transportation. In the era when animal power dominated transportation there was no safe way to cross east–west in the middle of the range.
The eastern head of the Ridge and Valley region is marked by the Great Appalachian Valley, which lies just west of the Blue Ridge. The western side of the Ridge and Valley region is marked by steep escarpments such as the Allegheny Front, the Cumberland Mountains, Walden Ridge; these curious formations are the remnants of an ancient fold-and-thrust belt, west of the mountain core that formed in the Alleghenian orogeny. Here, strata have been folded westward, forced over massive thrust faults; the ridges represent the edges of the erosion-resistant strata, the valleys portray the absence of the more erodible strata. Smaller streams have developed their valleys following the lines of the more eroded strata, but a few major rivers, such as the Delaware River, the Susquehanna River, the New River, the Potomac River, are evidently older than the present mountains, having cut water gaps that are perpendicular to hard strata ridges. The evidence points to a wearing down of the entire region to a low level with little relief, so that major rivers were flowing in unconsolidated sediments that were unaffected by the underlying rock structure.
The region was uplifted enough that the rivers were able to maintain their course, cutting through the ridges as they developed. Valleys may be anticlinal valleys; these mountains are at their highest development in central Pennsylvania, a phenomenon termed the Pennsylvania climax. Geology of the Appalachians Allegheny Front Eastern Continental Divide Tennessee Valley Divide Stanley, Steven M. Earth System History. New York: W. H. Freeman and Company, 1999. ISBN 0-7167-2882-6