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143-680: Greenside Mine (sometimes referred to as Greenside Lead Mine ) was a successful lead mine in the Lake District of England. Between 1825 and 1961 the mine produced 156,000 long tons (159,000 tonnes) of lead and 1,600,000 ounces (45 tonnes) of silver , from around 2 million tons of ore . During the 1940s it was the largest producer of lead ore in the UK. Unusually for a 19th-century metalliferous mine in Britain there are very full records of its activities, dating back to 1825. The mine probably opened during

286-558: A census in Patterdale in 1787 recorded 16 miners out of a male population of 165 and a writer in 1789 spoke of social changes "about thirty years ago" resulting from an influx of miners when "some lead mines were wrought in the dale." Yet there is nothing to link any of these references to Greenside. W. T. Shaw claimed Greenside was being worked by "a party of Dutch Adventurers" (probably meaning German miners) by 1690, but cited no evidence for this, and may have been thinking of other mines in

429-399: A colloform , agate -like habit, of sequential selvages of minerals which radiate out from nucleation points on the vein walls and appear to fill up the available open space. Often evidence of fluid boiling is present. Vugs , cavities and geodes are all examples of open-space filling phenomena in hydrothermal systems. Alternatively, hydraulic fracturing may create a breccia which

572-428: A building and a scattering of coal, coke, slag and iron. Gilgower's level was identified with a waste heap and entrance cutting at 582 metres AOD. Below this was evidence of another level, driven at an elevation of 572 metres AOD. With a stone-walled entrance cutting and a substantial waste heap it appeared to be a major level, and had been driven from the bottom of the prospecting hush mentioned above. This level

715-428: A commercial smelter. Machinery in the mine and the mills was powered by the plentiful water supplies in the area, used to drive water wheels and power hydraulic engines, and, after 1890, to generate hydroelectricity . Dozens of carts transported supplies to the mine's remote location, and carried the lead out. In the early 1900s the mine set up its own road haulage business using two steam wagons . The men who worked at

858-416: A dead rent of £225 per year for five years, with a reduced scale of royalties payable on top of the rent after that time. The mine returned to profitability during the 1920s but was beset by a series of difficulties, and then a falling lead price in the 1930s. A reservoir dam collapsed in 1927, sending a catastrophic flood through Glenridding village. Fortunately no one was killed, but compensation claims cost

1001-432: A defined area around the mine and equal shares of the royalties from the produce of the mine. They then granted a fourteen-year lease to the new company on 31 May 1827 in return for 1/9th of the value of the smelted lead, and the following day, 1 June 1827, a partnership agreement was signed by ten shareholders in the company. Thomas Cant died in 1831. Changes in share ownership over the next few years gave control of

1144-433: A density of 11.34 g/cm , which is greater than that of common metals such as iron (7.87 g/cm ), copper (8.93 g/cm ), and zinc (7.14 g/cm ). This density is the origin of the idiom to go over like a lead balloon . Some rarer metals are denser: tungsten and gold are both at 19.3 g/cm , and osmium —the densest metal known—has a density of 22.59 g/cm , almost twice that of lead. Lead

1287-492: A few radioactive isotopes. One of them is lead-210; although it has a half-life of only 22.2 years, small quantities occur in nature because lead-210 is produced by a long decay series that starts with uranium-238 (that has been present for billions of years on Earth). Lead-211, −212, and −214 are present in the decay chains of uranium-235, thorium-232, and uranium-238, respectively, so traces of all three of these lead isotopes are found naturally. Minute traces of lead-209 arise from

1430-399: A fraction of an inch up to 30 feet (9.1 m) or more. Barren sections were generally 5 to 7 feet (1.5 to 2.1 m) wide; worked areas varied from 6 feet (1.8 m) to as much as 40 or 50 feet (12 or 15 m). In the upper part of the mine, where strings of lead had penetrated the hanging wall, it was sometimes worth cutting away an opening 30 to 60 feet (9.1 to 18.3 m) wide, but in

1573-530: A good lead price the company was content to leave the mine open. It is probable that the Basinghall Mining Syndicate went into liquidation in 1954 because a new company called Greenside Mines Ltd. was set up in March 1954 to run the mine. Finally in 1958 the decision was made not to finance any further development work at the mine, to draw out the remaining ore and close at the end of 1959. Just before

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1716-441: A lack of working capital . However, the company wanted to be sure that Greenside Mine contained sufficient reserves of ore to enable the large-scale mining operation which would make it profitable. They proposed taking a two-year option on the mine, during which they would refurbish the property and prove its resources, paying the landowners a dead rent of £90 per year. Many terms of the old leases they rejected as inappropriate to

1859-457: A large, modern mining company. They proposed a fixed royalty payment of 1/40th (5%) of the value of the lead concentrates, arguing that if the mine was worked on a large enough scale, these royalties would be quite satisfactory to the landowners. Urgent repairs to the mine, especially to the two underground shafts, were begun immediately, and Dr. W. R. Jones of the Royal School of Mines examined

2002-472: A lateral extension of the vein. The hillside was covered with a thick layer of peat, and a number of Italian prisoners of war were employed to try to trace the outcrop of the vein. To help with the search, an electrical resistivity survey was carried out towards the end of 1943, and trenches were dug to investigate places on Hart Side where there were promising indications. However, only small stringers of barren quartz were found there. Underground prospecting

2145-429: A length of 3,900 feet (1,200 m) and to a depth of 2,900 feet (880 m). Four areas of the vein, known as ore shoots , contained galena , an ore of lead which also contained small amounts of silver. At first the ore was mined simply by driving adits into the mountain-side. To access ore at greater depths, two longer levels were driven from lower down but further away, and then a series of shafts were sunk within

2288-435: A lot of mining work had been done before William Sheffield abandoned the mine, some time before 1819. In addition, a fourth old level (the "Hush Level", see below) was driven in this early period, and a fifth level (later known as the "High Level", or the "High Horse Level") had been started before the mine was abandoned. The Greenside Vein may have been discovered among the rocks at the top of Glencoyne, where it outcrops and

2431-406: A natural gully intersected the vein high up (close to where the base of the highest of the collapse holes is today) and pieces of ore may have been found in the gully. Further down the hillside hushing has been used to reveal the position of the vein, by releasing a dammed up stream to wash away the boulder clay. A survey of the surface features at Greenside Mine in the early 1990s found no sign of

2574-558: A neutron and become thallium-204; this undergoes beta decay to give stable lead-204; on capturing another neutron, it becomes lead-205, which has a half-life of around 17 million years. Further captures result in lead-206, lead-207, and lead-208. On capturing another neutron, lead-208 becomes lead-209, which quickly decays into bismuth-209. On capturing another neutron, bismuth-209 becomes bismuth-210, and this beta decays to polonium-210, which alpha decays to lead-206. The cycle hence ends at lead-206, lead-207, lead-208, and bismuth-209. In

2717-409: A new investment by the old shareholders and negotiated new terms with the landowners. Shareholders agreed to a reconstruction of the company which involved allotting four new £1 ordinary shares for each of the 7,680 old shares, and issuing 4,280 preference shares to raise money needed for development of the mine. The new 1923 Greenside Mining Company Ltd. came into being, and the landowners agreed

2860-618: A north–south oriented fault running through the east ridge of the Green Side mountain. Green Side is composed of andesite rock, part of the Borrowdale Volcanic Group , formed during the Ordovician Period, roughly 450 million years ago. This rests on shales of the older Skiddaw Group , which were encountered in the lowest levels of the mine. A small dyke of porphyritic microgranite which has "a dog's-leg shape" in plan

3003-466: A polyhedral vertex and contributes two electrons to each covalent bond along an edge from their sp hybrid orbitals, the other two being an external lone pair . They may be made in liquid ammonia via the reduction of lead by sodium . Lead can form multiply-bonded chains , a property it shares with its lighter homologs in the carbon group. Its capacity to do so is much less because the Pb–Pb bond energy

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3146-437: A significant partial positive charge on lead. The result is a stronger contraction of the lead 6s orbital than is the case for the 6p orbital, making it rather inert in ionic compounds. The inert pair effect is less applicable to compounds in which lead forms covalent bonds with elements of similar electronegativity, such as carbon in organolead compounds. In these, the 6s and 6p orbitals remain similarly sized and sp hybridization

3289-438: A single decay chain). In total, 43 lead isotopes have been synthesized, with mass numbers 178–220. Lead-205 is the most stable radioisotope, with a half-life of around 1.70 × 10  years. The second-most stable is lead-202, which has a half-life of about 52,500 years, longer than any of the natural trace radioisotopes. Bulk lead exposed to moist air forms a protective layer of varying composition. Lead(II) carbonate

3432-525: A smelter at Stoneycroft in the Newlands Valley, near Keswick. The Greenside Mining Syndicate was formed "near the end of the 18th century" according to W. T. Shaw. The source of this information is not known but Samuel Murphy thought that this syndicate was "probably William Sheffield's company." The Greenside Mining Company was formed in the 1820s to reopen and work the abandoned mine. Four local businessmen were behind this venture, led by Thomas Cant,

3575-449: A structure, with every alternate layer of oxygen atoms absent. Negative oxidation states can occur as Zintl phases , as either free lead anions, as in Ba 2 Pb, with lead formally being lead(−IV), or in oxygen-sensitive ring-shaped or polyhedral cluster ions such as the trigonal bipyramidal Pb 5 ion, where two lead atoms are lead(−I) and three are lead(0). In such anions, each atom is at

3718-491: A successful grocer in the nearby town of Penrith . They took control of the mine in early 1825, as reported by The Westmorland Gazette on 26 March 1825. Four miners were employed initially and mining operations were supervised by a mine agent. Two local landowners claimed the mineral rights of the area where the mine was situated. Fortunately, they came to an amicable agreement in December 1826 which gave them joint ownership of

3861-523: A sump (a vertical working) which had been made below Gilgower's Level. This created natural ventilation in the mine, and enabled the work to be expanded. By 1834 92 men were employed underground. The High Horse Level was continued northwards and in 1837 it crossed the northern boundary of the area shared by the two landowners. To reach ore lower than the High Horse Level, access levels had to be driven from much further away, or shafts had to be sunk within

4004-473: A team of Canadian Engineers with diamond drilling equipment, and this confirmed that the Skiddaw Group of rocks lay at about 217 fathoms (397 m) below the main entrance to the mine (The Lucy Level), not at 300 fathoms (550 m) as the geologists had predicted. The rich bonanza of ore the company had expected was not there. A programme of surface prospecting was undertaken at once in an attempt to find

4147-499: A time when many British lead mines were closing, these men decided to face the financial challenges and keep the mine working. The mine returned to profitability and began paying dividends again in the financial year 1888/89. The Greenside Mining Company Ltd. was created in October 1889 to give shareholders the protection of limited liability in this challenging time. The old company was wound up; its lease and other assets were sold to

4290-590: Is 6 times higher, copper 10 times, and mild steel 15 times higher); it can be strengthened by adding small amounts of copper or antimony . The melting point of lead—at 327.5 °C (621.5 °F) —is very low compared to most metals. Its boiling point of 1749 °C (3180 °F) is the lowest among the carbon-group elements. The electrical resistivity of lead at 20 °C is 192 nanoohm -meters, almost an order of magnitude higher than those of other industrial metals (copper at 15.43 nΩ·m ; gold 20.51 nΩ·m ; and aluminium at 24.15 nΩ·m ). Lead

4433-516: Is a neurotoxin that accumulates in soft tissues and bones. It damages the nervous system and interferes with the function of biological enzymes , causing neurological disorders ranging from behavioral problems to brain damage, and also affects general health, cardiovascular, and renal systems. Lead's toxicity was first documented by ancient Greek and Roman writers, who noted some of the symptoms of lead poisoning , but became widely recognized in Europe in

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4576-401: Is a superconductor at temperatures lower than 7.19  K ; this is the highest critical temperature of all type-I superconductors and the third highest of the elemental superconductors. Natural lead consists of four stable isotopes with mass numbers of 204, 206, 207, and 208, and traces of six short-lived radioisotopes with mass numbers 209–214 inclusive. The high number of isotopes

4719-420: Is a common constituent; the sulfate or chloride may also be present in urban or maritime settings. This layer makes bulk lead effectively chemically inert in the air. Finely powdered lead, as with many metals, is pyrophoric , and burns with a bluish-white flame. Fluorine reacts with lead at room temperature, forming lead(II) fluoride . The reaction with chlorine is similar but requires heating, as

4862-775: Is a mixed sulfide derived from galena; anglesite , PbSO 4 , is a product of galena oxidation; and cerussite or white lead ore, PbCO 3 , is a decomposition product of galena. Arsenic , tin , antimony , silver , gold , copper , bismuth are common impurities in lead minerals. World lead resources exceed two billion tons. Significant deposits are located in Australia, China, Ireland, Mexico, Peru, Portugal, Russia, United States. Global reserves—resources that are economically feasible to extract—totaled 88 million tons in 2016, of which Australia had 35 million, China 17 million, Russia 6.4 million. Typical background concentrations of lead do not exceed 0.1 μg/m in

5005-426: Is a strong oxidizing agent, capable of oxidizing hydrochloric acid to chlorine gas. This is because the expected PbCl 4 that would be produced is unstable and spontaneously decomposes to PbCl 2 and Cl 2 . Analogously to lead monoxide , lead dioxide is capable of forming plumbate anions. Lead disulfide and lead diselenide are only stable at high pressures. Lead tetrafluoride , a yellow crystalline powder,

5148-404: Is a very soft metal with a Mohs hardness of 1.5; it can be scratched with a fingernail. It is quite malleable and somewhat ductile. The bulk modulus of lead—a measure of its ease of compressibility—is 45.8  GPa . In comparison, that of aluminium is 75.2 GPa; copper 137.8 GPa; and mild steel 160–169 GPa. Lead's tensile strength , at 12–17 MPa, is low (that of aluminium

5291-445: Is common for the carbon group. The divalent state is rare for carbon and silicon , minor for germanium, important (but not prevailing) for tin, and is the more important of the two oxidation states for lead. This is attributable to relativistic effects , specifically the inert pair effect , which manifests itself when there is a large difference in electronegativity between lead and oxide , halide , or nitride anions, leading to

5434-408: Is consistent with lead's atomic number being even. Lead has a magic number of protons (82), for which the nuclear shell model accurately predicts an especially stable nucleus. Lead-208 has 126 neutrons, another magic number, which may explain why lead-208 is extraordinarily stable. With its high atomic number, lead is the heaviest element whose natural isotopes are regarded as stable; lead-208

5577-414: Is exploited in the synthesis of other lead compounds. Few inorganic lead(IV) compounds are known. They are only formed in highly oxidizing solutions and do not normally exist under standard conditions. Lead(II) oxide gives a mixed oxide on further oxidation, Pb 3 O 4 . It is described as lead(II,IV) oxide , or structurally 2PbO·PbO 2 , and is the best-known mixed valence lead compound. Lead dioxide

5720-546: Is filled with vein material. Such breccia vein systems may be quite extensive, and can form the shape of tabular dipping sheets, diatremes or laterally extensive mantos controlled by boundaries such as thrust faults , competent sedimentary layers , or cap rocks . On the macroscopic scale, the formation of veins is controlled by fracture mechanics, providing the space for minerals to precipitate. Failure modes are classified as (1) shear fractures, (2) extensional fractures, and (3) hybrid fractures, and can be described by

5863-502: Is more prevalent than most other elements with atomic numbers greater than 40. Primordial lead—which comprises the isotopes lead-204, lead-206, lead-207, and lead-208—was mostly created as a result of repetitive neutron capture processes occurring in stars. The two main modes of capture are the s- and r-processes . In the s-process (s is for "slow"), captures are separated by years or decades, allowing less stable nuclei to undergo beta decay . A stable thallium-203 nucleus can capture

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6006-650: Is not stable, as both the lead(III) ion and the larger complexes containing it are radicals . The same applies for lead(I), which can be found in such radical species. Numerous mixed lead(II,IV) oxides are known. When PbO 2 is heated in air, it becomes Pb 12 O 19 at 293 °C, Pb 12 O 17 at 351 °C, Pb 3 O 4 at 374 °C, and finally PbO at 605 °C. A further sesquioxide , Pb 2 O 3 , can be obtained at high pressure, along with several non-stoichiometric phases. Many of them show defective fluorite structures in which some oxygen atoms are replaced by vacancies: PbO can be considered as having such

6149-741: Is over three and a half times lower than that of the C–C bond . With itself, lead can build metal–metal bonds of an order up to three. With carbon, lead forms organolead compounds similar to, but generally less stable than, typical organic compounds (due to the Pb–C bond being rather weak). This makes the organometallic chemistry of lead far less wide-ranging than that of tin. Lead predominantly forms organolead(IV) compounds, even when starting with inorganic lead(II) reactants; very few organolead(II) compounds are known. The most well-characterized exceptions are Pb[CH(SiMe 3 ) 2 ] 2 and plumbocene . The lead analog of

6292-405: Is plenty of fluid flow and open space to deposit ore minerals. Ores related to hydrothermal mineralisation, which are associated with vein material, may be composed of vein material and/or the rock in which the vein is hosted. In many gold mines exploited during the gold rushes of the 19th century, vein material alone was typically sought as ore material. In most of today's mines, ore material

6435-402: Is primarily composed of the veins and some component of the wall rocks which surrounds the veins. The difference between 19th-century and 21st-century mining techniques and the type of ore sought is based on the grade of material being mined and the methods of mining which are used. Historically, hand-mining of gold ores permitted the miners to pick out the lode quartz or reef quartz, allowing

6578-415: Is stable, but less so than the difluoride . Lead tetrachloride (a yellow oil) decomposes at room temperature, lead tetrabromide is less stable still, and the existence of lead tetraiodide is questionable. Some lead compounds exist in formal oxidation states other than +4 or +2. Lead(III) may be obtained, as an intermediate between lead(II) and lead(IV), in larger organolead complexes; this oxidation state

6721-413: Is still energetically favorable. Lead, like carbon, is predominantly tetravalent in such compounds. There is a relatively large difference in the electronegativity of lead(II) at 1.87 and lead(IV) at 2.33. This difference marks the reversal in the trend of increasing stability of the +4 oxidation state going down the carbon group; tin, by comparison, has values of 1.80 in the +2 oxidation state and 1.96 in

6864-448: Is the heaviest stable nucleus. (This distinction formerly fell to bismuth , with an atomic number of 83, until its only primordial isotope , bismuth-209, was found in 2003 to decay very slowly.) The four stable isotopes of lead could theoretically undergo alpha decay to isotopes of mercury with a release of energy, but this has not been observed for any of them; their predicted half-lives range from 10 to 10 years (at least 10 times

7007-529: Is the origin of the English word " plumbing ". Its ease of working, its low melting point enabling the easy fabrication of completely waterproof welded joints, and its resistance to corrosion ensured its widespread use in other applications, including pharmaceuticals, roofing, currency, warfare. Writers of the time, such as Cato the Elder , Columella , and Pliny the Elder , recommended lead (and lead-coated) vessels for

7150-525: Is the so-called inert pair effect : the 6s electrons of lead become reluctant to participate in bonding, stabilising the +2 oxidation state and making the distance between nearest atoms in crystalline lead unusually long. Lead's lighter carbon group congeners form stable or metastable allotropes with the tetrahedrally coordinated and covalently bonded diamond cubic structure. The energy levels of their outer s- and p-orbitals are close enough to allow mixing into four hybrid sp orbitals. In lead,

7293-555: Is to us. Heinz Eschnauer and Markus Stoeppler "Wine—An enological specimen bank", 1992 Mineral vein Veins are classically thought of as being planar fractures in rocks, with the crystal growth occurring normal to the walls of the cavity, and the crystal protruding into open space. This certainly is the method for the formation of some veins. However, it is rare in geology for significant open space to remain open in large volumes of rock, especially several kilometers below

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7436-446: Is usefully exploited: lead tetraacetate is an important laboratory reagent for oxidation in organic synthesis. Tetraethyllead, once added to automotive gasoline, was produced in larger quantities than any other organometallic compound, and is still widely used in fuel for small aircraft . Other organolead compounds are less chemically stable. For many organic compounds, a lead analog does not exist. Lead's per-particle abundance in

7579-404: Is visible. One branch of the vein was partly cut away at the outcrop, and a bell pit known as Duke's Sump was sunk on another branch "at some early date." Whether lead was found is not known. The vein may also have been discovered high up on the south side of Green Side. The hillside there is covered by a thick deposit of glacial boulder clay , hiding the rich lead-bearing vein from view. However,

7722-595: The Carboniferous Period, led to mineralisation of the fault cavities. The metal content is believed to have been leached out of rocks of the Skiddaw Group, or the underlying granite batholith . The mineralisation of the fault shows some vertical zonation, with baryte (barium sulphate) in the upper part of the vein, and small amounts of both blende ( sphalerite , zinc sulphide) and chalcopyrite (copper-iron sulphide) at deeper levels. The argentiferous galena (lead sulphide, containing small amounts of silver), which

7865-608: The Phoenicians worked deposits in the Iberian peninsula ; by 1600 BC, lead mining existed in Cyprus , Greece , and Sardinia . Rome's territorial expansion in Europe and across the Mediterranean, and its development of mining, led to it becoming the greatest producer of lead during the classical era , with an estimated annual output peaking at 80,000 tonnes. Like their predecessors,

8008-659: The Solar System is 0.121  ppb (parts per billion). This figure is two and a half times higher than that of platinum , eight times more than mercury , and seventeen times more than gold . The amount of lead in the universe is slowly increasing as most heavier atoms (all of which are unstable) gradually decay to lead. The abundance of lead in the Solar System since its formation 4.5 billion years ago has increased by about 0.75%. The solar system abundances table shows that lead, despite its relatively high atomic number,

8151-795: The fall of Rome and did not reach comparable levels until the Industrial Revolution . Lead played a crucial role in the development of the printing press , as movable type could be relatively easily cast from lead alloys. In 2014, the annual global production of lead was about ten million tonnes, over half of which was from recycling. Lead's high density, low melting point, ductility and relative inertness to oxidation make it useful. These properties, combined with its relative abundance and low cost, resulted in its extensive use in construction , plumbing , batteries , bullets , shots , weights , solders , pewters , fusible alloys , lead paints , leaded gasoline , and radiation shielding . Lead

8294-401: The nucleus , and more shielded by smaller orbitals. The sum of the first four ionization energies of lead exceeds that of tin, contrary to what periodic trends would predict. This is explained by relativistic effects , which become significant in heavier atoms, which contract s and p orbitals such that lead's 6s electrons have larger binding energies than its 5s electrons. A consequence

8437-619: The +2 oxidation state rather than the +4 state common with lighter members of the carbon group . Exceptions are mostly limited to organolead compounds . Like the lighter members of the group, lead tends to bond with itself ; it can form chains and polyhedral structures. Since lead is easily extracted from its ores , prehistoric people in the Near East were aware of it . Galena is a principal ore of lead which often bears silver. Interest in silver helped initiate widespread extraction and use of lead in ancient Rome . Lead production declined after

8580-468: The +4 state. Lead(II) compounds are characteristic of the inorganic chemistry of lead. Even strong oxidizing agents like fluorine and chlorine react with lead to give only PbF 2 and PbCl 2 . Lead(II) ions are usually colorless in solution, and partially hydrolyze to form Pb(OH) and finally [Pb 4 (OH) 4 ] (in which the hydroxyl ions act as bridging ligands ), but are not reducing agents as tin(II) ions are. Techniques for identifying

8723-406: The 1880s, part of a worldwide economic recession known as the long depression , created financial difficulties for the mine. The lead price had fallen by 50%, and reached a minimum of £10.69 per ton in 1884, the result of large-scale imports of cheap foreign lead. No dividends were paid to shareholders for the seven years from 1881 to 1887, and in 1884 a call was made on shareholders of £25 per share,

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8866-564: The Basinghall Mining Syndicate Ltd. acquired the mine and turned it into a high volume lead producer. The mine closed in 1962 after lead reserves had been exhausted. Just before it closed the mine was used by the Atomic Weapons Research Establishment (AWRE) to conduct an experiment in detecting seismic signals from underground explosions. Fifteen years after the mine closed mine explorers began to visit

9009-606: The Egyptians had used lead for sinkers in fishing nets , glazes , glasses , enamels , ornaments . Various civilizations of the Fertile Crescent used lead as a writing material , as coins , and as a construction material . Lead was used by the ancient Chinese as a stimulant , as currency , as contraceptive , and in chopsticks . The Indus Valley civilization and the Mesoamericans used it for making amulets ; and

9152-532: The Mohr-Griffith-Coulomb fracture criterion. The fracture criterion defines both the stress required for fracturing and the fracture orientation, as it is possible to construct on a Mohr diagram the shear fracture envelope that separates stable from unstable states of stresses. The shear fracture envelope is approximated by a pair of lines that are symmetric across the σ n axis. As soon as the Mohr circle touches

9295-471: The Romans obtained lead mostly as a by-product of silver smelting. Lead mining occurred in central Europe , Britain , Balkans , Greece , Anatolia , Hispania , the latter accounting for 40% of world production. Lead tablets were commonly used as a material for letters. Lead coffins, cast in flat sand forms and with interchangeable motifs to suit the faith of the deceased, were used in ancient Judea . Lead

9438-507: The Top Level. Of the Middle Level it found a shallow surface cutting at 627 metres AOD, a hole where the roof of the level had collapsed, a small waste heap, and a steep sled track running down the hillside from this point. The remains of a smithy were found lower down, near the base of the middle collapse hole, where there was a flat area at 584 metres AOD, with the foundations of

9581-600: The atmosphere; 100 mg/kg in soil; 4 mg/kg in vegetation, 5 μg/L in fresh water and seawater. The modern English word lead is of Germanic origin; it comes from the Middle English leed and Old English lēad (with the macron above the "e" signifying that the vowel sound of that letter is long). The Old English word is derived from the hypothetical reconstructed Proto-Germanic * lauda- ('lead'). According to linguistic theory, this word bore descendants in multiple Germanic languages of exactly

9724-432: The company negotiated a fourteen-year extension to their lease (in 1835), giving them security until 1862. In 1853 the company again sought an extended lease. Again they were planning a new even lower level to exploit ore reserves at greater depths in the mine, and this would require years of work. This time the landowners took the opportunity to introduce some changes to the terms of the lease. William Marshall in particular

9867-581: The company over £4,500, several years' worth of profits. A replacement reservoir dam, built at a cost of nearly £11,000, also failed in August 1931 and the reservoir was then abandoned. In the same month one of the shafts in the mine collapsed, and collapsed again in December 1933. The falling lead price led to a reduction in the number of employees, from 68 to 53 in February 1931, and down to 40 in July 1932. The chairman of

10010-469: The company to a new group of men. The principal shareholder was George Head Head , a Quaker banker from Carlisle , who owned 18 of the 64 shares by 1835. A new mine agent was appointed in 1832, and mining operations were greatly expanded, with 90 men being employed by 1834. A major investment was needed to access ore beneath the current level of the mine, but this meant driving a new level in barren ground for hundreds of yards. To safeguard their investment

10153-534: The company, J. W. Pattinson, died in April 1931, after serving as chairman for 24 years. He was replaced by J. C. Kidd, another long-standing director, and Captain Borlase's son-in-law. He carefully analysed the decline in the company's profitability, concluding that the price of lead was simply too low. Operations were gradually scaled down, and a loss of £1,635 was made in the year to March 1933. The amount of proven ore reserves

10296-485: The course of the Earth's history, have remained in the crust instead of sinking deeper into the Earth's interior. This accounts for lead's relatively high crustal abundance of 14 ppm; it is the 36th most abundant element in the crust. The main lead-bearing mineral is galena (PbS), which is mostly found with zinc ores. Most other lead minerals are related to galena in some way; boulangerite , Pb 5 Sb 4 S 11 ,

10439-419: The current age of the universe). Three of the stable isotopes are found in three of the four major decay chains : lead-206, lead-207, and lead-208 are the final decay products of uranium-238 , uranium-235 , and thorium-232 , respectively. These decay chains are called the uranium chain , the actinium chain , and the thorium chain . Their isotopic concentrations in a natural rock sample depends greatly on

10582-428: The diiodide . Many lead(II) pseudohalides are known, such as the cyanide, cyanate, and thiocyanate . Lead(II) forms an extensive variety of halide coordination complexes , such as [PbCl 4 ] , [PbCl 6 ] , and the [Pb 2 Cl 9 ] n chain anion. Lead(II) sulfate is insoluble in water, like the sulfates of other heavy divalent cations . Lead(II) nitrate and lead(II) acetate are very soluble, and this

10725-588: The district. David Gough claimed "the first documentary evidence of mining at Greenside" was dated 1784, but also failed to say what that evidence was. Samuel Murphy discovered what he considered "the first documentary evidence" in the form of a barrister's brief of 1799, which referred to a Mr. Thompson who was working a mine at Greenside under the Duke of Norfolk. Murphy also found a reference to Greenside in William Green's guide book of 1819. The mines were said to be "beside

10868-459: The east-west Clay Vein by splitting into a number of small stringers, described as "a horsetail structure". All attempts to find the vein south of the Clay Vein were unsuccessful. The northern end of the vein was never determined, but all searches for lead beyond the limit of the northernmost ore shoot (about 3,600 feet (1,100 m) from the southern end) were also unsuccessful. The vertical extent of

11011-515: The eastern and southern Africans used lead in wire drawing . Because silver was extensively used as a decorative material and an exchange medium, lead deposits came to be worked in Asia Minor from 3000 BC; later, lead deposits were developed in the Aegean and Laurion . These three regions collectively dominated production of mined lead until c.  1200 BC . Beginning c. 2000 BC,

11154-566: The element its chemical symbol Pb . The word * ɸloud-io- is thought to be the origin of Proto-Germanic * bliwa- (which also means 'lead'), from which stemmed the German Blei . The name of the chemical element is not related to the verb of the same spelling, which is derived from Proto-Germanic * laidijan- ('to lead'). Metallic lead beads dating back to 7000–6500 BC have been found in Asia Minor and may represent

11297-465: The end of June 1944. The high level of production proved to be unsustainable. Development work of new reserves could not keep pace with the production of 6,000 tons of crude ore per month. In January 1943 production had to be scaled down, and the ore dressing mill reduced to a single shift per day. But a bigger blow was to follow. In May 1943, as one of the shafts was being deepened, the miners encountered bands of soft, black shale . The Ministry sent in

11440-574: The end of the 19th century, the main access to the mine was from the Lucy Tongue Level, which had been driven from near the bottom of the Swart Beck. The mills for processing and smelting the ore were in the same location, 1.4 miles (2.3 km) up the valley above Glenridding village. Water power for working machinery in the mine and the mills was drawn from the stream below Green Side, and from Glenridding Beck. A number of dams were built to regulate

11583-413: The first example of metal smelting . At that time, lead had few (if any) applications due to its softness and dull appearance. The major reason for the spread of lead production was its association with silver, which may be obtained by burning galena (a common lead mineral). The Ancient Egyptians were the first to use lead minerals in cosmetics, an application that spread to Ancient Greece and beyond;

11726-399: The first time this had ever been necessary. Even the royalties due to the landowners could not be paid in 1884. The debt was carried over and repaid over the next ten years. Royalties in fact consumed 69% of the working profit of the mine during the decade from 1880 to 1890 as they were based on the amount of lead produced. This was in spite of a new lease which reduced royalties to 1/12 part of

11869-605: The flow of water in these becks, and natural tarns at Red Tarn and in Keppel Cove were augmented. After 1890, water power from the becks was used to generate electricity and eventually three small power stations were built. A small stream was also diverted into the mine through the Glencoyne Level in the 1850s to drive hydraulic machinery. The entire production of the Greenside Mine came from a single mineral vein , which filled

12012-430: The group. Lead dihalides are well-characterized; this includes the diastatide and mixed halides, such as PbFCl. The relative insolubility of the latter forms a useful basis for the gravimetric determination of fluorine. The difluoride was the first solid ionically conducting compound to be discovered (in 1834, by Michael Faraday ). The other dihalides decompose on exposure to ultraviolet or visible light, especially

12155-409: The highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is a relatively unreactive post-transition metal . Its weak metallic character is illustrated by its amphoteric nature; lead and lead oxides react with acids and bases , and it tends to form covalent bonds . Compounds of lead are usually found in

12298-403: The highest-grade portions of the lodes to be worked, without dilution from the unmineralised wall rocks. Today's mining, which uses larger machinery and equipment, forces the miners to take low-grade waste rock in with the ore material, resulting in dilution of the grade. However, today's mining and assaying allows the delineation of lower-grade bulk tonnage mineralisation, within which the gold

12441-446: The inert pair effect increases the separation between its s- and p-orbitals, and the gap cannot be overcome by the energy that would be released by extra bonds following hybridization. Rather than having a diamond cubic structure, lead forms metallic bonds in which only the p-electrons are delocalized and shared between the Pb ions. Lead consequently has a face-centered cubic structure like

12584-403: The labour costs while maintaining or improving production rates. He did so by introducing the latest technical innovations such as electrical power and equipment to the mine. A new 21-year lease was negotiated in 1901 and to cope with changing market conditions royalties were set on a scale which depended on the price of lead, varying from 1/30 when it was below £10 per ton, to 1/10 when the price

12727-406: The lake, to the state of the roads and the cleanliness of the workers’ accommodation. In the fifty years to 1876 Greenside produced about 60,000 long tons (61,000 tonnes) of ore, which had yielded 40,000 long tons (41,000 tonnes) of lead, worth £800,000, and 600,000 ounces (17 tonnes) of silver, worth £150,000. Profits of £300,000 had been divided among the shareholders. Poor economic conditions in

12870-447: The late 19th century AD. A lead atom has 82 electrons , arranged in an electron configuration of [ Xe ]4f 5d 6s 6p . The sum of lead's first and second ionization energies —the total energy required to remove the two 6p electrons—is close to that of tin , lead's upper neighbor in the carbon group . This is unusual; ionization energies generally fall going down a group, as an element's outer electrons become more distant from

13013-560: The latter being stable only above around 488 °C. Litharge is the most commonly used inorganic compound of lead. There is no lead(II) hydroxide; increasing the pH of solutions of lead(II) salts leads to hydrolysis and condensation. Lead commonly reacts with heavier chalcogens. Lead sulfide is a semiconductor , a photoconductor , and an extremely sensitive infrared radiation detector . The other two chalcogenides, lead selenide and lead telluride , are likewise photoconducting. They are unusual in that their color becomes lighter going down

13156-441: The latter is not; this allows for lead–lead dating . As uranium decays into lead, their relative amounts change; this is the basis for uranium–lead dating . Lead-207 exhibits nuclear magnetic resonance , a property that has been used to study its compounds in solution and solid state, including in the human body. Apart from the stable isotopes, which make up almost all lead that exists naturally, there are trace quantities of

13299-515: The lead produced, signed on 16 November 1883. At the same time there had been changes among the shareholders of the mine. George Head Head had died in 1876 and Miles MacInnes , his adopted heir, became the principal shareholder. Two other large shareholders died in 1882. MacInnes was discouraged by the prospects of the mine and disposed of all his shares in 1884 following the £25 call on them. But new directors, led by Robert Bradshaw Smith and John Pattinson, began to increase production and cut costs. At

13442-460: The levels, or sumps below them. The ore was usually removed by overhead stoping (called "roofing" locally), that is, by cutting away the roof of a level. Wooden working platforms were built above the level, supported on heavy beams wedged between the two sides of the vein. The ore was dropped down from the stopes to the level below, filled into wooden wheelbarrows and wheeled out. In places the workings could be as much as 60 feet (18 m) wide where

13585-437: The lines of the fracture envelope that represent a critical state of stress, a fracture will be generated. The point of the circle that first touches the envelope represents the plane along which a fracture forms. A newly formed fracture leads to changes in the stress field and tensile strength of the fractured rock and causes a drop in stress magnitude. If a stress increases again, a new fracture will most likely be generated along

13728-409: The lower workings during the 1950s stopes averaged 6 feet (1.8 m) wide. Two branch veins occurred in connection with the microgranite dyke. At higher levels the vein divided and ran along both sides of the dyke. At greater depth, where the vein was within andesite to the west of the dyke, an East Branch was found in contact with the dyke. At its southern end the vein came to an end as it approached

13871-443: The marsh, which could be supplied with a more reliable water supply. A leat had collected water from the original stream, 36 metres above the old dressing floor, and conducted it to some small storage ponds further east, which could collect from other sources as well. However the site of the new washing floor had been destroyed by a later mine building. After the ore had been dressed it was taken by packhorses over Sticks Pass to

14014-451: The mine and acquire its entire lead output. A contract was agreed in July 1942, under which the Ministry paid for the operating costs of the mine, for all approved development work and for any plant or equipment needed. The company continued to run the mine on behalf of the Ministry, and in lieu of profits were paid 30 shillings for each dry ton of lead concentrates. This agreement lasted until

14157-506: The mine and the surface facilities for high production three- shift working. By September 1939 the two parent companies had invested £160,000 in share capital and £57,000 in loans to finance the venture, and the company's balance sheet showed a loss of £79,712 following the major expenditure that had been incurred. But by 1940 Greenside Mine had become the largest producer of lead ore in the United Kingdom. Over 220 people were employed at

14300-533: The mine during the 19th century travelled from a wide area, and many stayed each week in the lodging shops (bunkhouses) built at the mine. In time the company built dozens of houses in Glenridding and at Seldom Seen in Glencoynedale where a school was also built. Mining work was carried out by groups of men who took contracts to do specific jobs, and were paid by their results. Those who worked transporting ore out of

14443-409: The mine in 1941, when production peaked at over 5,000 tons of lead per year. However, this did not immediately translate into profits because of high development costs, and operating losses continued to be made until 1941 World War II had begun in 1939, just as the large-scale working of the mine began. Lead was a nationally important commodity, and the wartime Ministry of Supply wanted to take over

14586-607: The mine or processing the ore were paid at weekly rates. The closure of the mine resulted in a major loss of employment in the area. The mine was west of Glenridding village, which is by the southern end of Ullswater in the parish of Patterdale . This is now in Cumbria , but during the working life of the mine it was in the former county of Westmorland . Above the village is a valley which contains Glenridding Beck, flowing down from sources in Red Tarn and Brown Cove. A higher side valley to

14729-472: The mine to keep it in profit, while making sure no ore reserves would be lost when the mine did close. Everything possible was done to control costs and maximise income. But this was not the high output mine the Basinghall Mining Syndicate had seen itself running, and they announced production would cease in 1946. However, in the year to September 1946 the mine made its best profit to date, of £19,926. A steady development programme kept production constant, and with

14872-465: The mine was due to close, the company was offered a reasonable fee to allow the Atomic Weapons Research Establishment (AWRE) to conduct an experiment in detecting seismic signals from underground explosions as part of Operation Orpheus. When the testing programme was completed in August 1960, control of the mine returned to the Greenside company. The last of the ore was stripped out by April 1961, equipment

15015-422: The mine. Lead Lead (pronounced "led") is a chemical element ; it has symbol Pb (from Latin plumbum ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable , and also has a relatively low melting point . When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has

15158-411: The mine. The lowest point in the mine was roughly 100 m below sea level, where the surrounding andesite rock rested upon underlying shales in which the fault had not been mineralised. Two processing mills were built to crush the ore and separate out the galena from it, and the mine had its own smelt mill between 1828 and 1917, but after that it was more economical to sell concentrated galena to

15301-446: The miners sought, occurred as ribs, strings and dispersed pockets throughout the vein. Many strings of galena, varying in thickness between 1/8 of an inch (2 mm) and about three inches (76 mm), were interspersed through the vein, and sometimes spread into the rock on the east side of the vein (the hanging wall of the fault). The mineralised parts of the vein were mostly found in four areas, known as " ore shoots ." Their position

15444-533: The neutrons are arranged in complete shells in the atomic nucleus, and it becomes harder to energetically accommodate more of them. When the neutron flux subsides, these nuclei beta decay into stable isotopes of osmium , iridium , platinum . Lead is classified as a chalcophile under the Goldschmidt classification , meaning it is generally found combined with sulfur. It rarely occurs in its native , metallic form. Many lead minerals are relatively light and, over

15587-432: The new company for £61,440. One hundred and twenty shares in the new company were allotted to each of the sixty four shares in the old company. One of the first acts of the new company was to employ an experienced mining engineer as their chief mine agent. Captain W. H. Borlase was recruited for his ability to manage mines under difficult circumstances. His approach was to work the mine as economically as possible by reducing

15730-444: The north lies between the mountains of Green Side and Raise . It was above this side valley that the lead deposit was found, running through the eastern ridge of Green Side, at a height of about 2,000 feet (600 m) above sea level. In the 18th century this deposit was worked from levels driven directly into the mountain-side, above the upper valley. Later, levels were driven to the deposit from lower down but from further away. By

15873-423: The ore had been brought out of the mine it had to be separated from rock and other vein minerals ( gangue ). The surface survey found evidence of an early dressing floor beside the marsh on the valley floor, at 550 metres AOD, where a little stream provided a small source of water. In that area were found many pieces of very weathered galena. It also found the washings had later been moved to another area beside

16016-403: The ore reserves and prospects for the mine. His preliminary report was positive, and the company began a large-scale chemical sampling programme, which also produced good results. An increase in the lead price in late 1936 also brightened the prospects for the mine. The company decided to purchase the mine from the liquidators in July 1937. Over the next two years a lot of work was done to prepare

16159-763: The plane of extension within the rock mass, give or take a sizeable bit of error. Measurement of enough veins will statistically form a plane of principal extension. In ductilely deforming compressional regimes, this can in turn give information on the stresses active at the time of vein formation. In extensionally deforming regimes, the veins occur roughly normal to the axis of extension. Veins are common features in rocks and are evidence of fluid flow in fracture systems. Veins provide information on stress, strain, pressure, temperature, fluid origin and fluid composition during their formation. Typical examples include gold lodes , as well as skarn mineralisation. Hydrofracture breccias are classic targets for ore exploration as there

16302-418: The preparation of sweeteners and preservatives added to wine and food. The lead conferred an agreeable taste due to the formation of "sugar of lead" ( lead(II) acetate ), whereas copper vessels imparted a bitter flavor through verdigris formation. This metal was by far the most used material in classical antiquity, and it is appropriate to refer to the (Roman) Lead Age. Lead was to the Romans what plastic

16445-414: The presence of the Pb ion in water generally rely on the precipitation of lead(II) chloride using dilute hydrochloric acid. As the chloride salt is sparingly soluble in water, in very dilute solutions the precipitation of lead(II) sulfide is instead achieved by bubbling hydrogen sulfide through the solution. Lead monoxide exists in two polymorphs , litharge α-PbO (red) and massicot β-PbO (yellow),

16588-422: The presence of these three parent uranium and thorium isotopes. For example, the relative abundance of lead-208 can range from 52% in normal samples to 90% in thorium ores; for this reason, the standard atomic weight of lead is given to only one decimal place. As time passes, the ratio of lead-206 and lead-207 to lead-204 increases, since the former two are supplemented by radioactive decay of heavier elements while

16731-432: The r-process (r is for "rapid"), captures happen faster than nuclei can decay. This occurs in environments with a high neutron density, such as a supernova or the merger of two neutron stars . The neutron flux involved may be on the order of 10 neutrons per square centimeter per second. The r-process does not form as much lead as the s-process. It tends to stop once neutron-rich nuclei reach 126 neutrons. At this point,

16874-467: The renewal of the lease were begun, and the company, aware of their dire financial position, sought a reduction of the royalties payable. But the landowners and their advisors rejected all the company's suggestions. As a result, the company went into voluntary liquidation in November 1920. Attempts to sell the mine, or its assets, came to nothing. Eventually Captain Borlase, who had retired in 1919, proposed

17017-541: The resulting chloride layer diminishes the reactivity of the elements. Molten lead reacts with the chalcogens to give lead(II) chalcogenides. Lead metal resists sulfuric and phosphoric acid but not hydrochloric or nitric acid ; the outcome depends on insolubility and subsequent passivation of the product salt. Organic acids, such as acetic acid , dissolve lead in the presence of oxygen. Concentrated alkalis dissolve lead and form plumbites . Lead shows two main oxidation states: +4 and +2. The tetravalent state

17160-419: The road from Keswick to Patterdale" and were "till lately worked by William Sheffield Esquire ," the mineral agent to the Duke of Devonshire. The road mentioned is clearly the track over Sticks Pass , which passes the old workings at Greenside. A vertical section through Greenside Mine was drawn by a consultant mining engineer in 1853. This shows three old access levels above the two levels which were in use at

17303-447: The same fracture plane. This process is known as the crack-seal mechanism Crack-seal veins are thought to form quite quickly during deformation by precipitation of minerals within incipient fractures. This happens swiftly by geologic standards, because pressures and deformation mean that large open spaces cannot be maintained; generally the space is in the order of millimeters or micrometers . Veins grow in thickness by reopening of

17446-507: The same meaning. There is no consensus on the origin of the Proto-Germanic * lauda- . One hypothesis suggests it is derived from Proto-Indo-European * lAudh- ('lead'; capitalization of the vowel is equivalent to the macron). Another hypothesis suggests it is borrowed from Proto-Celtic * ɸloud-io- ('lead'). This word is related to the Latin plumbum , which gave

17589-550: The second half of the 1700s but had closed by 1819. In 1825 the Greenside Mining Company was formed and reopened the mine. They made good profits until 1880, when the price of lead fell. Many other lead mines closed at that time, but the company reduced its costs and continued to work Greenside until 1935. Electricity was introduced to the mine in the 1890s, and it became the first metalliferous mine in Britain to use electric winding engines and an electric locomotive. In 1936

17732-491: The similarly sized divalent metals calcium and strontium . Pure lead has a bright, shiny gray appearance with a hint of blue. It tarnishes on contact with moist air and takes on a dull appearance, the hue of which depends on the prevailing conditions. Characteristic properties of lead include high density , malleability, ductility, and high resistance to corrosion due to passivation . Lead's close-packed face-centered cubic structure and high atomic weight result in

17875-588: The simplest organic compound , methane , is plumbane . Plumbane may be obtained in a reaction between metallic lead and atomic hydrogen. Two simple derivatives, tetramethyllead and tetraethyllead , are the best-known organolead compounds. These compounds are relatively stable: tetraethyllead only starts to decompose if heated or if exposed to sunlight or ultraviolet light. With sodium metal, lead readily forms an equimolar alloy that reacts with alkyl halides to form organometallic compounds such as tetraethyllead. The oxidizing nature of many organolead compounds

18018-468: The surface. Thus, there are two main mechanisms considered likely for the formation of veins: open-space filling and crack-seal growth . Open space filling is the hallmark of epithermal vein systems, such as a stockwork , in greisens or in certain skarn environments. For open space filling to take effect, the confining pressure is generally considered to be below 0.5 GPa , or less than 3–5 km (2–3 mi). Veins formed in this way may exhibit

18161-501: The time, and large areas of stoped out (worked out) ground. W. T. Shaw calculated that the old levels, known as Top Level, Middle Level and Gilgower's Level, had been driven at 40 fathoms (73 m; 240 ft), 60 fathoms (110 m; 360 ft) and 85 fathoms (155 m; 510 ft) below the summit of the ridge. Samuel Murphy calculated that the three levels had been 659 metres above ordnance datum (AOD), 631 metres AOD and 581 metres AOD. These three old levels imply

18304-520: The upper levels. They cleared the entrances and several roof falls, and today they are able to pass through the mine using an old escape route. All the ore produced by the mine came from the Greenside Vein, a mineral vein which filled a geological fault running in a north–south direction through the east ridge of Green Side , a mountain in the Helvellyn range . Mining activities traced this fault for

18447-413: The vein fracture and progressive deposition of minerals on the growth surface as well as being decomposable . Veins generally need either hydraulic pressure in excess of hydrostatic pressure (to form hydraulic fractures or hydrofracture breccias) or they need open spaces or fractures, which requires a plane of extension within the rock mass. In all cases except brecciation, therefore, a vein measures

18590-583: The vein had split into two distinct branches, or fissures to the east had been mineralised. These workings were left open with no support and the large holes on the hillside today show where they eventually collapsed. The High Horse Level had been started before the mine was abandoned in the 1810s, from the lowest possible point on the floor of the upper valley beneath Green Side. It was made wide enough and straight enough to allow horses to pull wagons of ore along it on narrow-gauge wooden rails. The new company drove this level forward, and in 1828 it broke through to

18733-458: The vein was traced and worked from the top of Green Side down to the upper boundary of the Skiddaw Group, a distance of 2,600 feet (790 m). Although lead veins have been found in rocks of the Skiddaw Group elsewhere in the Lake District, the strata at Green Side were unfavourable for mineralisation; these strata therefore marked the bottom of the mine. It is not known when the Greenside Vein

18876-403: The very rare cluster decay of radium-223, one of the daughter products of natural uranium-235, and the decay chain of neptunium-237, traces of which are produced by neutron capture in uranium ores. Lead-213 also occurs in the decay chain of neptunium-237. Lead-210 is particularly useful for helping to identify the ages of samples by measuring its ratio to lead-206 (both isotopes are present in

19019-431: Was above £17 per ton. World War I in 1914–1918 pushed up demand for lead and the market price, but the output of the mine fell as a result of three factors: poor ore, a shortage of miners, and two very dry summers which severely reduced the water supply to the power house. By 1918 production had fallen to 600 tons per year and essential development work of ore reserves had not been done. In 1919 negotiations for

19162-633: Was also done, by extending both the Lucy Level and the 120 Fathom Level to the north, but without success. A thorough review of the geology by the British Geological Survey in February 1944 pointed the way to some small deposits of ore but confirmed that no major extension to the reserves existed. When the mine was returned to the company in June 1944, production was scaled down and thirty men were discharged. The manager began to plan how best to work

19305-406: Was critical of the company's lack of engineering expertise and poor long-term planning. A key provision of the new lease was the appointment of an independent consultant engineer as mineral agent, paid for by the company but appointed jointly by the landowners and the company. Other provisions sought to mitigate some of the nuisances caused by a working mine in the area, from pollution of the river and

19448-414: Was determined by the steepness of the fault plane. In general, areas where the fault dipped at more than 70°, were mineralised, but where the dip was less than 70° the vein was barren, filled with the light coloured soft fault breccia which the miners called "chunk." The mineralised parts of the vein, at least in the lower part of the mine, had an average lead content of 7%. The width of the vein varied from

19591-455: Was first discovered, or when mining began there, but the amount of mining work done before 1820 suggests a date during the second half of the 1700s. There was mining activity in Patterdale throughout the 18th century. A lease for the mining rights at Hartsop Hall Mine is dated 1696; the parish registers recorded the burials of "a washer of ore" in 1713 and of a miner from Derbyshire in 1754;

19734-677: Was intruded into these rocks during the Devonian Period; this formed a plane of weakness which controlled the position of the fault. The Greenside fault is a normal fault with an average dip of 70° to the east. A fault plane is not a flat surface and the actual dip of the Greenside fault varies between 58° east and vertical; in one place it was 83° west. As the rock fractured and the two sides moved against each other, cavities were created, partly filled with broken rock ( fault breccia and fault gouge ). Hydrothermal circulation of sea water at temperatures of 110–130 °C, probably during

19877-476: Was involved with the running of a large lead mine in North Wales near Pentre Halkyn , but lead reserves there were coming to an end, and when the Greenside Mine closed, BMC was already looking for a possible new venture. In 1936, BMC with a subsidiary of Associated Lead Manufactures Ltd. formed The Basinghall Mining Syndicate Ltd. to explore the possibility of purchasing Greenside, believing it had only failed from

20020-496: Was not shown on the mine plan of 1853, and Murphy named it the Hush Level. A shallow water channel ran from its mouth and seemed to have drained the mine for a considerable time. The earliest Ordnance Survey map of the area, the 1861 map of Westmorland at a scale of 1:2,500, shows two mine levels, corresponding to Gilgower's Level and the Hush Level. Both are marked "Old Mine" showing they were no longer in use at that late date. Once

20163-512: Was sold off, most of the buildings were demolished and the site cleaned up. The final twelve workmen were paid off in January 1962. The 18th-century mine workings began from adits driven into the sloping hillside along the line of the vein. These were known as the Top Level , Middle Level and Gilgower's Level . As each level was extended further into the hill, ore was obtained by cutting rises above

20306-416: Was still increasing, but the company was unable to finance the exploitation of new ground. Knowing the mine could be made profitable, the manager made a last attempt, in February 1934, to persuade the board of directors to inject enough capital to make Greenside a large-scale producer. No action was taken on his report and the company went into liquidation in March 1935. The British Metal Corporation (BMC)

20449-522: Was used to make sling bullets from the 5th century BC. In Roman times, lead sling bullets were amply used, and were effective at a distance of between 100 and 150 meters. The Balearic slingers , used as mercenaries in Carthaginian and Roman armies, were famous for their shooting distance and accuracy. Lead was used for making water pipes in the Roman Empire ; the Latin word for the metal, plumbum ,

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