Slate is produced on the east coast of Newfoundland in Eastern Pennsylvania Buckingham County Virginia and the Slate Valley of Vermont and New York where colored slate is mined in the Granville
Granville
Granville is a village in Licking County, Ohio, United States. The population was 5,646 at the 2010 census. The village is located in a rural area of rolling hills in central Ohio. It is 35 miles east of Columbus, the state capital, and 7 miles west of Newark, the county seat.
Where was slate first found in the UK?
Where is Slate Found in the UK? Slate is found in Wales and the North-West of England. More specifically, you will find the majority of UK slate mines in Cornwall (famously Delabole quarry) and in the Lake District in Cumbria. The slate industry is worldwide, with 90% of Europe’s natural slate used for roofing originating in Spain.
Where does natural slate come from?
Where does natural slate come from? The majority of slate supplied in Europe is Spanish – about 90%. Some slate is also quarried in Wales and small amounts in Cumbria and Cornwall, but the vast majority of slate used in the UK is Spanish. Other sources outside Europe include China and the USA.
Where and how slate was formed?
Slate is formed through the regional metamorphosis of mudstone or shale under low-pressure conditions. When shale or mudstone is exposed to heavy pressure and heat from a tectonic plate activity, its clay mineral components metamorphose into mica minerals. Mica minerals such as biotite, chlorite, and muscovite, are the main components of slate.
Is slate a metamorphic rock?
Slate is a metamorphic rock which was originally the sedimentary rock shale. The rock can be a variety of colors such as red, gray, or green. Slate has a fine-grained texture and is often used as a building material. Slate can be easily broken into sheets. An information card with details on the rock formation, mineral content, characteristics, and uses is included.
Where does slate come from?
Most slate in Europe today comes from Spain, the world's largest producer and exporter of natural slate, and 90 percent of Europe's natural slate used for roofing originates from the slate industry there.
Where is slate found in Europe?
Lesser slate-producing regions in Europe include Wales (with a museum at Llanberis ), Cornwall (famously the village of Delabole ), Cumbria (see Burlington Slate Quarries, Honister Slate Mine and Skiddaw Slate) and, formerly in the West Highlands of Scotland, around Ballachulish and the Slate Islands in the United Kingdom. Parts of France ( Anjou, Loire Valley, Ardennes, Brittany, Savoie) and Belgium (Ardennes), Liguria in northern Italy, especially between the town of Lavagna (which means chalkboard in Italian) and Fontanabuona valley; Portugal especially around Valongo in the north of the country.
What is slate rock?
Slate is a fine-grained metamorphic rock that shows no obvious compositional layering, but can easily be split into thin slabs and plates. It is usually formed by low-grade regional metamorphism of mudrock. This mild degree of metamorphism produces a rock in which the individual mineral crystals remain microscopic in size, producing a characteristic slaty cleavage in which fresh cleavage surfaces appear dull. This is in contrast to the silky cleaved surfaces of phyllite, which is the next higher grade of metamorphic rock derived from mudstone. The direction of cleavage is independent of any sedimentary structures in the original mudrock, reflecting instead the direction of regional compression.
What is foliation in slate?
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.
Why is slate considered a metamorphic rock?
Because slate was formed in low heat and pressure, compared to a number of other metamorphic rocks, some fossils can be found in slate; sometimes even microscopic remains of delicate organisms can be found in slate.
What is slate cleavage?
Slaty cleavage is continuous, meaning that the individual cleavage planes are too closely spaced to be discernible in hand samples. The texture of the slate is totally dominated by these pervasive cleavage planes. Under the microscope, the slate is found to consist of very thin lenses of quartz and feldspar (QF-domains) separated by layers of mica (M-domains). These are typically less than 100 microns thick.
Why is slate used in a lab?
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. Due to its thermal stability and chemical inertness, slate has been used for laboratory bench tops and for billiard table tops.
What is Slate?
S late is a fine-grained, foliated metamorphic rock that is created by the alteration of shale or mudstone by low-grade regional metamorphism. It is popular for a wide variety of uses such as roofing, flooring, and flagging because of its durability and attractive appearance.
What are the minerals in slate?
Slate can also contain abundant quartz and small amounts of feldspar, calcite, pyrite, hematite, and other minerals. Slate roof: Most of the slate mined throughout the world is used to produce roofing slates.
What forces modify the clay minerals in the shale and mudstone?
These forces and heat modify the clay minerals in the shale and mudstone. Foliation develops at right angles to the compressive forces of the convergent plate boundary to yield a vertical foliation that usually crosses the bedding planes that existed in the shale. ADVERTISEMENT.
What is slate tile?
Slate tile flooring: Slate is a durable rock that is suitable for use as flooring, stair treads, sidewalk slabs, and patio stone. It is also produced in a variety of colors that allow it to be incorporated into a variety of design projects. Shown above are multi-color flooring tiles.
What causes foliation in slate?
Foliation in slate is caused by the parallel orientation of platy minerals in the rock, such as microscopic grains of clay minerals and mica. These parallel mineral grain alignments give the rock an ability to break smoothly along planes of foliation.
What is the name of the rock that forms the roof and floor of a coal mine?
In the coal mining industry of the Appalachian Basin, the word "slate" is still used by many miners in reference to the shale that forms the roof and floor of a mine, and for fragments of shale that are separated from the coal in preparation plants. Experienced miners train newer miners, and archaic language is passed along.
What is the tectonic environment for producing slate?
The tectonic environment for producing slate is usually a former sedimentary basin that becomes involved in a convergent plate boundary. Shales and mudstones in that basin are compressed by horizontal forces with minor heating. These forces and heat modify the clay minerals in the shale and mudstone. Foliation develops at right angles ...
Where is slate made?
Slate is produced from all over the world but the best slate is produced in United Kingdom and Brazil.
What is slate used for?
Slate has been used for thousands of years from old school blackboards, roofing, flooring and construction in the 19th century. Slate is a popular material to use in these builds due to its attractive and decorative appearance as well as its durability.
How was slate freed?
Slate would be freed from the rock by blasting in shot holes then later drilled into the rock. Miners would return to the surface with large slabs of rocks where the work force on the surface would split and cut it into standard sized roofing tiles. These underground mines were closed off by the early 1960’s due to the danger of miners and the public entering them. Today most of the mines have collapsed and left nothing to show the hard work and times when these were a big part of our slate industry. However Wales have left an open and reinforced mine as a tourist attraction that has been seen by thousands of people to this day.
Is slate mined?
Slate has been mined around the world for centuries and this was recently confirmed by a discovery of a 16th century wooden ship that was found to be carrying finished slates on board.
Where is slate mined?
In Europe, most slate is mined in Spain. It is also mined in the United Kingdom, and parts of France, Italy, and Portugal. Brazil is the second-biggest producer of slate. In the Americas, it's also found in Newfoundland, Pennsylvania, New York, Vermont, Maine, and Virginia.
What type of rock is slate?
Slate is a fine-grained, metamorphic rock formed by compression of sedimentary shale, mudstone, or basalt.
What is the finest grained metamorphic rock?
Slate is the finest-grained metamorphic rock, which means you have to examine it closely to see its structure. It's also a foliated rock that displays what is called "slaty cleavage.". Slaty cleavage occurs when fine clay flakes grow in a plane perpendicular to the compression.
What is slate rock?
Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. Slate is a metamorphic rock with a dull luster.
How to tell shale from slate?
One way to tell shale and slate apart is to strike it with a hammer. Slate emits a "tink" or a ring when struck. Shale and mudstone produce a dull thud. A sheet of smooth stone used for writing might be referred to as a "slate," regardless of its composition.
How is slate formed?
Slate is formed when a sedimentary rock (shale, mudstone, or basalt) is compressed. Over time, slate may transition into other metamorphic rocks, such as phyllite or schist. You've likely encountered slate on a building or an old chalkboard.
What are the minerals in slate?
Other minerals found in slate can include biotite, chlorite, hematite, pyrite, apatite, graphite, kaolinite, magnetite, feldspar, tourmaline, and zircon. Some samples of slate appear spotted. These spots typically appear when iron is reduced. The spots may be spherical or appear as ovoids when stress deforms the rock.
What is Stone Mountain known for?
Its granite was used in the locks of the Panama Canal and in steps to the U.S. Capitol building. The mountain is known for its Confederate memorial carving started by Gutzon Borglum and for association with the Ku Klux Klan revival in 1916.
Where is Chile Bar Slate located?
Chile Bar Slate company,off of highway CA193 next to the American River.*historical site. Limestone quarry near Auburn, California of the Mountain Quarries Company of San Francisco, a subsidiary of Pacific Portland Cement Company, near confluence of the North Fork and the Middle Fork of the American River.
How many tons of granite did the Quincy Quarries produce?
By 1888, the company employed over 200 workers, and produced about 30,000 tons of granite per year. Quincy Quarries Reservation, in Quincy, Massachusetts, producer of granite from 1826 to 1963, including for the Bunker Hill Monument.
Which state has the most granite quarries?
According to Marble.com, in 2016 there were 276 quarries producing natural stone in 34 states, and states producing the most granite were Texas, Massachusetts , Indiana, Wisconsin, and Georgia. The term "quarry" refers also to sites producing aggregate, molding sand, or other resources besides cut stone. There were numerous more quarries in the U.S.
Where is Willard Brook Quarry?
Willard Brook Quarry, in Piscataquis County, Maine, near Chisuncook, Maine, NRHP-listed. Franklin, Maine, granite quarries, in one of which the NRHP-listed Robertson Quarry Galamander, a customized wagon for stone, was found.
Where is the Yule Marble quarry located?
Marble, Colorado, only site of Yule Marble quarrying, in the West Elk Mountains. 99.5% pure calcite, discovered in 1873, source of marble for the Tomb of the Unknowns and for the exterior of the Lincoln Memorial
Where is Stringfellow Acid Pits?
Stringfellow Acid Pits a former rock quarry in Jurupa Valley in Riverside County, California, which became a toxic waste dump and later a Superfund site. Deemed one of the most polluted sites in California in 1980s, and associated with mismanagement and scandal in the U.S. Environmental Protection Agency.
Overview
Further reading
• Page, William (ed.) (1906). The Victoria History of the County of Cornwall; vol. I. (Chapter on quarries.) Westminster: Constable.
• Hudson, Kenneth (1972). Building Materials; "Chapter 2: Stone and Slate". pp London: Longman, pp. 14–27. ISBN 0-582-12791-2.
Description
Slate is a fine-grained metamorphic rock that shows no obvious compositional layering, but can easily be split into thin slabs and plates. It is usually formed by low-grade regional metamorphism of mudrock. This mild degree of metamorphism produces a rock in which the individual mineral crystals remain microscopic in size, producing a characteristic slaty cleavage in which fresh cle…
Uses
Slate can be made into roofing slates, a type of roof shingle, or more specifically 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 relatively flat and easy to stack. A series of "slate booms" occurred in Europe fr…
Slate extraction
Most slate in Europe today comes from Spain, the world's largest producer and exporter of natural slate, and 90 percent of Europe's natural slate used for roofing originates from the slate industry there.
Lesser slate-producing regions in Europe include Wales (with a museum at Llanberis), Cornwall (famously the village of Delabole), Cumbria (see Burlington S…
Fossils
Because slate was formed in low heat and pressure, compared to a number of other metamorphic rocks, some fossils can be found in slate; sometimes even microscopic remains of delicate organisms can be found in slate.
External links
• AditNow—Photographic database of mines
• Granville Slate Museum
• Hower’s Lightning Slate Reckoner (1884/1904), by F. M. Hower, Cherryville, Penn., on Stone Quarries and Beyond (PDF/18.95 MB)
Composition
Appearance
- Most slates are gray in color and range in a continuum of shades from light to dark gray. Slate also occurs in shades of green, red, black, purple, and brown. The color of slate is often determined by the amount and type of iron and organic material that are present in the rock.
Formation
- The tectonic environment for producing slate is usually a former sedimentary basin that becomes involved in a convergent plate boundary. Shales and mudstones in that basin are compressed by horizontal forces with minor heating. These forces and heat modify the clay minerals in the shale and mudstone. Foliation develops at right angles to the compre...
Etymology
- The word \"slate\" has not been used consistently over time and in some industries. Today most geologists are careful not to use the word \"slate\" when talking about \"shale.\" However, in the past the word slate was often used freely in reference for shale. This confusion of terms partially arises from the fact that shale is progressively converted into slate. Imagine driving your car eas…
Usage
- In the 1800s, elementary school students used a small piece of slate mounted in a wooden frame for writing practice and arithmetic problems. Writing was done with a small pencil made of slate, soapstone, or clay. The slate could be wiped clean with a soft cloth. Small slates were also used in schools and businesses to list daily events, schedules, menus, prices, and other notices. Toda…
Advantages
- Most of the slate mined throughout the world is used to produce roofing slates. Slate performs well in this application because it can be cut into thin sheets, absorbs minimal moisture, and stands up well in contact with freezing water. A disadvantage is the cost of the slate and its installation in comparison with other roofing materials. As a result, in new construction slate is …
Other uses
- Slate is also used for interior flooring, exterior paving, dimension stone, and decorative aggregate. Small pieces of slate are also used to make turkey calls. The photos on this page document several uses of slate. Historically slate has been used for chalkboards, student writing slates, billiard tables, cemetery markers, whetstones, and table tops. Because it is a good electrical ins…
North Wales
- Penrhyn Quarry
- Cwt-y-Bugail Quarry
- Delabole Quarry
- Mill Hill Quarry
Slate and Its UK Locations
- The slate industry is worldwide, with 90% of Europe’s natural slateused for roofing originating in Spain. The US also possesses important producing regions, with the state of New York being home to The Slate Valley area, being one of the places in the world where coloured slate (which is not grey or blue) is obtained. Today, however, we’re putting ...
North Wales – Penrhyn Quarry
- The Welsh slate industry has an extensive history. It began in the Roman period, when slate was used to roof the fort at Segontium, now Caernarfon. The first large-scale slate mining in North Wales began with the opening of Penrhyn Quarry in 1782 (back then known as Cae Braich y Cafn quarry). However, the first reference to slate extraction from Penrhyn is from back in 1570, whe…
North Wales – Cwt-Y-Bugail Quarry
- Cwt y Bugail Quarry is located above Ffestiniog in North Wales. It first worked as a trial pit around 1840 and produces dark blue grey slate. Today it is an open cast quarry, whereas slate was originally mined in deep caverns and pillars. In fact, during World War II the quarry was used to store art treasures from the National Gallery and the Tate Gallery for safe keeping. At UK Slate, …
Cornwall – Delabole Quarry & Mill Hill Quarry
- Delabole Quarry is one of the largest slate quarries in England and has operated since the 15th century, making it the oldest working quarry in England. It was once the deepest man-made pit in the world until open cast mines were made in America and Australia. Once worked by over 1,000 people, today the work of that many can be done with just a few machines and five quarrymen. …