Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Chalk is common throughout Western Europe, where deposits underlie parts of France, and steep cliffs are often seen where they meet the sea in places such as the Dover cliffs on the Kent coast of the English Channel.
A gunnies, gunnis, or gunniss is the space left in a mine after the extraction by stoping of a vertical or near vertical ore-bearing lode. The term is also used when this space breaks the surface of the ground, but it can then be known as a coffin or goffen. It can also be used to describe the deep trenches that were dug by early miners in following the ore-bearing lode downwards from the surface – in this case they are often called open-works; their existence can provide the earliest evidence of mining in an area. William Pryce, writing in 1778, also used the term as a measure of width, a single gunnies being equal to three feet.
A sinkhole, also known as a cenote, sink, sink-hole, swallet, swallow hole, or doline, is a depression or hole in the ground caused by some form of collapse of the surface layer. Most are caused by karst processes – the chemical dissolution of carbonate rocks or suffosion processes. Sinkholes vary in size from 1 to 600 m both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may form gradually or suddenly, and are found worldwide.
A tunnel boring machine (TBM), also known as a "mole", is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They may also be used for microtunneling. They can be designed to bore through anything from hard rock to sand. Tunnel diameters can range from one metre (3.3 ft) to 17.6 metres (58 ft) to date. Tunnels of less than a metre or so in diameter are typically done using trenchless construction methods or horizontal directional drilling rather than TBMs. TBMs can also be designed to excavate non-circular tunnels, including u-shaped or horseshoe and square or rectangular tunnels.
The Comstock Lode is a lode of silver ore located under the eastern slope of Mount Davidson, a peak in the Virginia Range in Virginia City, Nevada, which was the first major discovery of silver ore in the United States and named after American miner Henry Comstock.
The Lochnagar mine south of the village of La Boisselle in the Somme département was an underground explosive charge, secretly planted by the British during the First World War, to be ready for 1 July 1916, the first day on the Somme. The mine was dug by the Tunnelling Companies of the Royal Engineers under a German field fortification known as Schwabenhöhe.
Drift mining is either the mining of an ore deposit by underground methods, or the working of coal seams accessed by adits driven into the surface outcrop of the coal bed. A drift mine is an underground mine in which the entry or access is above water level and generally on the slope of a hill, driven horizontally into the ore seam. Random House dictionary says the origin of the term "drift mine" is an Americanism, circa 1885–1890.
Cissbury Ring is an 84.2-hectare (208-acre) biological Site of Special Scientific Interest north of Worthing in West Sussex. It is owned by the National Trust and is designated a Scheduled monument for its Neolithic flint mine and Iron Age hillfort.
Drilling and blasting is the controlled use of explosives and other methods such as gas pressure blasting pyrotechnics, to break rock for excavation. It is practiced most often in mining, quarrying and civil engineering such as dam, tunnel or road construction. The result of rock blasting is often known as a rock cut.
Retsof is a hamlet and census-designated place (CDP) within the town of York in Livingston County, New York, United States. The community, situated 30 miles (48 km) southwest of the city of Rochester, is off New York State Route 63 approximately one mile east of State Route 36. As of the 2010 census, it had a population of 340.
Tunnel warfare is a general name for war being conducted in tunnels and other underground cavities. It often includes the construction of underground facilities in order to attack or defend, and the use of existing natural caves and artificial underground facilities for military purposes. Tunnels can be used to undermine fortifications and slip into enemy territory for a surprise attack, while it can strengthen a defence by creating the possibility of ambush, counterattack and the ability to transfer troops from one portion of the battleground to another unseen and protected. Also, tunnels can serve as shelter for combatants and non-combatants from enemy attack.
Marvel Cave is a National Natural Landmark located just west of Branson, Missouri, on top of Roark Mountain in Stone County. The cave was known by the Osage Indians in the early 16th century, after a tribe member fell through the cave's main entrance, a sinkhole. There is evidence that in 1541 the Spanish explored the cave, but the first recorded expedition was in 1869, led by Henry T. Blow. The unofficial Stone County chapter of Bald Knobbers, a local group of vigilantes, were rumored to have taken people to the top of Roark Mountain, and thrown them in the sink hole.
The Plantation Garden is a restored Victorian town garden located off Earlham Road, Norwich, Norfolk. As of 2021, visitors are asked to pay £2 to visit the garden, which is open daily throughout the year.
Royal Engineer tunnelling companies were specialist units of the Corps of Royal Engineers within the British Army, formed to dig attacking tunnels under enemy lines during the First World War.
Eckington mine was a drift mine situated on the eastern edge of the township of Eckington, Derbyshire, England, 7 miles (11 km) South-West of Sheffield. As of 2011, it was the only colliery in production in North East Derbyshire.
The Hohenzollern Redoubt action, 2–18 March 1916 was fought on the Western Front during the First World War. The Hohenzollern Redoubt was a German defensive position north of Loos-en-Gohelle (Loos), a mining town north-west of Lens in France. The Redoubt was fought over by the British and German armies from the Battle of Loos to the beginning of the Battle of the Somme on 1 July 1916. Over the winter of 1915–1916, the 170th Tunnelling Company RE dug several galleries under the German lines in the area of the redoubt, which had changed hands several times since September 1915. In March 1916, the west side was held by the British and the east side was occupied by the Germans, with the front near a new German trench known as The Chord. No man's land had become a crater field and the Germans had an unobstructed view of the British positions from the Fosse 8 slag heap. The British front line was held by outposts to reduce the number of troops vulnerable to mine explosions and the strain of knowing that the ground could erupt at any moment.
At the start of the Battle of Messines (7–14 June 1917) during the First World War, underground explosive charges were detonated by the British Second Army beneath the forward position of the German 4th Army near the village of Mesen, in Belgian West Flanders. The mines, secretly planted by British tunnelling units, created 19 large craters and killed approximately 10,000 German soldiers. Their joint explosion ranks among the largest non-nuclear explosions of all time.
The 179 Tunnelling Company was one of the tunnelling companies of the Royal Engineers created by the British Army during World War I. The tunnelling units were occupied in offensive and defensive mining involving the placing and maintaining of mines under enemy lines, as well as other underground work such as the construction of deep dugouts for troop accommodation, the digging of subways, saps, cable trenches and underground chambers for signals and medical services. 179th Tunnelling Company is particularly known for its role at L'îlot de La Boisselle and for firing the Lochnagar mine during the Battle of the Somme 1916. The Lochnagar mine formed part of a series of 19 mines that were placed beneath the German lines on the British section of the Somme front to assist the start of the battle.
The 19 mines on the first day of the Somme comprised a series of underground explosive charges, secretly planted by British tunnelling units beneath the German front lines on the Western Front during the First World War, ready to be detonated in the morning of Saturday 1 July 1916, the first day of the Battle of the Somme. The joint explosion of these mines ranks among the largest artificial non-nuclear explosions.
In the mid-19th century, Colorado Springs was a center of mining industry activity. Coal was mined in 50 mines in the area and towns, now annexed to Colorado Springs, were established to support residents of the coal mining industry.
