Copper mine on Virgin Gorda

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Copper mine on Virgin Gorda
General information about the mine
Copper Mine, Virgin Gorda.jpg
Ruins of the copper mine on Virgin Gorda
Mining technology Underground mining
Information about the mining company
Employees 174
Start of operation 1835
End of operation 1862
Funded raw materials
Degradation of copper
copper

Gang name

Whitley's Lode
Mightiness 0.6
Greatest depth 110 m
overall length 1250 m
Geographical location
Coordinates 18 ° 25 '58 "  N , 64 ° 25' 28"  W Coordinates: 18 ° 25 '58 "  N , 64 ° 25' 28"  W.
Copper mine on Virgin Gorda, British Virgin Islands
Copper mine on Virgin Gorda
Location copper mine on Virgin Gorda
Location Copper Mine Point
local community Spanish Town
British overseas territory British Virgin Islands
Country British Virgin Islands

The copper mine on Virgin Gorda was a mine that was operated on the island of Virgin Gorda , which belongs to the British Virgin Islands , a British overseas territory in the Caribbean, between 1835 and 1862 in two short periods of mining for the extraction of copper ore .

geography

location

The ruins of the mine are located at the Copper Mine Point named after him in the extreme southeast of the island of Virgin Gorda. The Copper Mine Road, laid out by miners in 1840, connects the mine site with Spanish Town, the main settlement of Virgin Gorda about two kilometers to the northwest.

geology

The bright granodiorite rock of the Virgin Islands batholith characterizes - as here in "The Baths" - large sections of the rocky coastline in the south of Virgin Gorda.

The island of Virgin Gorda consists largely of rocks of the Virgin Islands batholith (also known as Virgin Gorda batholith), a deep rock body that was created in connection with subduction processes on the arch of the island in the Greater Antilles , uplifted by tectonic processes and exposed by erosion . The south coast of the island pending granodiorite has an age of 37.6 million years. Near the Copper Mine Point, the rock is traversed by a north-trending fault zone to which chalcopyrite and molybdenite mineralized quartz veins are bound.

The mine built on a hydrothermal transition deposits caused by several wells to a depth developed and approximately 110 meters in strike was to the north and south on a length of about 450 tracks to 800 meters. In seigerem distance of around 18 meters were six soles attached; the ascended distances ranged partially below the seabed.

The main ore was the "Whitley's Lode", named after the main shareholder in the mine. This passage was a good half a meter thick on average. With increasing depth it widened to around a meter in diameter and carried larger quantities of solid copper. The gangue was quartz, with chalcopyrite (CuFeS 2 ) and molybdenite (MoS 2 ) as the primary ores . Because the mining interest was strictly for the copper, the molybdenite was to stockpile thrown.

The outcrop of the deposit is easily recognizable because of its striking color from secondary mineral formations such as malachite in the bright, granodiorite cliffs.

history

Before the arrival of the Europeans, the copper deposits on Virgin Gorda were used by the people who originally lived here to make tools and jewelry. After Christopher Columbus discovered the Virgin Islands , Spanish settlers and later possibly Dutch miners sporadically mined here; mining probably came to a standstill in the first third of the 18th century.

At the instigation of plantation owners from Virgin Gorda, who had got into economic difficulties after the abolition of slavery in 1834 and were looking for sales opportunities for their products, English investors founded the "Virgin Gorda Mining Company" in 1835 under the leadership of Liverpool lawyer John Whitley with the aim of to resume mining operations. Approximately 1,000 acres of land were acquired or leased and developed for the operation of the mine; a shaft was sunk in 1838. Because the ores found here appeared profitable, miners were recruited in Cornwall (31 men and 5 women) and a used steam engine and a steam boiler were bought. In addition, locals were hired for the work on the surface, including 64 women and children, who were mainly responsible for crushing and sorting the ores. A total of up to 174 people were employed. Because the operating company ran out of funds, mining had to be stopped in March 1842, despite good ore bursting. In this first operating period, a total of around 210 tons of ore concentrate with a copper content of 20% was extracted.

From 1859 the mine by the newly established company "Virgin Gorda Mine Adventure" was aufgewältigt . Cornish miners were hired again as contract workers. The wages paid, at nine pounds a month for work in the mine and five pounds for the times of the crossing, were high compared to the two to three pounds a month then customary in Cornwall. The steam boiler and steam engine were repaired and numerous buildings were erected, including a powder magazine and a large cistern with a collecting platform for rainwater. In June 1860 a new shaft was sunk to a depth of 73 meters, and an ore mill was installed. In the same year 150 tons of ore valued at 3000 pounds were exported. The following year production increased to 721 tons of ore valued at 10,120 pounds. As in the first operating period, the ore was shipped to Swansea in Wales for smelting . Conversely, the entire material requirements of the mine were imported from there. In 1861 that was 454 tons of coal, 190 gallons of machine oil , 26,000 feet of lumber, 12 tons of candles, and technical equipment valued at 243 pounds. The high wage and transport costs, rising taxes and duties, falling copper content of the mined ores and falling market prices for copper made profitable mining impossible, so that as early as 1862 the mine was shut down for good.

During the First World War , there was a small number of gleanings on molybdenum by searching the old dumps by hand for pieces of molybdenite. Approximately 30  cwt of ore valued at $ 1.50 per pound was exported in 1917. The examination of a sample of heap material at the beginning of the 1920s showed a content of 1.5% molybdenite.

Occasionally, further investigations of the deposit took place, most recently in 1970 by a Canadian company, but this did not lead to a resumption of mining.

After the first security measures at the ruins from 1998, the mine site was declared a “Copper Mine Point National Park” on March 28, 2003 due to its importance in terms of settlement and industrial history. The protected area has an area of ​​18.36 acres. A visitor center explaining the history of the mine opened on January 27, 2017, but was badly damaged by Hurricanes Irma and Maria that same year and closed indefinitely.

Current condition

Principle drawing of a "house-built engine"

In particular , there are still significant remains of the daytime facilities of the mine built in the mining period from 1859 to 1962 . As a highly visible landmarks , the nacelle and are particularly striking chimney , both into details similar to the corresponding facilities in Cornwall. The chimney has remains of the typical red brick crowning. The machine house, of which parts of three of the four outer walls still stand, and the steam engine were designed as a "house-built engine", whereby the building is an integral part of the machine, with one of the building walls also supporting the balance of the steam engine as a central support . The foundations of the boiler house still contain the rust- eaten remains of the steam boiler. The cistern is well preserved and there are remains of the collecting platform for rainwater as well as the foundation walls of the powder magazine and administration buildings.

Although the ensemble was placed under protection as a national park in 2003 , the ruins are endangered. The plants are exposed to salty air and frequent storms. Soil erosion, removal of bricks and the consequences of improper restoration measures affect the strength of the existing walls.

On the beach of Copper Mine Bay to the north of the mine, partly in shallow water, is the cast-iron balancer of the steam engine manufactured in 1836 in the Perran Foundry not far from Falmouth and installed on Virgin Gorda in 1840. It is one of the oldest still existing components of this type in the world.

The mine area offers opportunities to find minerals such as malachite , molybdenite and solid copper . More than 25 types of mineral, including rare ones, have been identified so far.

The crevices in the cliffs on the seashore are used by white-tailed tropical birds ( Phaethon lepturus ) as a breeding opportunity.

literature

Web links

Individual evidence

  1. ↑ a b c d e f g h i j k The Cornish Miner in The British Virgin Islands. In: Poldark Mine. Archived from the original on August 6, 2011 ; accessed on March 16, 2020 (English, archiving unfortunately without images).
  2. ↑ Frederic H. Wilson et al .: Preliminary Geologic Map of the Greater Antilles and the Virgin Islands - Pamphlet to accompany (=  Open-File Report . No. 2019-1036 ). United States Geological Survey, 2019, ISSN  2331-1258 , Igneous Rocks: Tertiary Intrusive Rocks - Ted, S. 35 , doi : 10.3133 / ofr20191036 (English, the areal extent of the rock formation described is shown in Sheet 2 ).
  3. ↑ Wayne T. Jolly et al .: Bimodal volcanism in northeast Puerto Rico and the Virgin Islands (Greater Antilles Island Arc): Genetic links with Cretaceous subduction of the mid-Atlantic ridge Caribbean spur . In: Lithos . tape 103 , no. 3-4 , July 2008, ISSN  0024-4937 , p. 393–414 , doi : 10.1016 / j.lithos.2007.10.008 (English, freely available online through redciencia.cu [PDF; 3.8 MB ; accessed on March 16, 2020]).
  4. ↑ Kevin Lee Schrecengost: Geochemistry and U / Pb zircon geochronology of the Virgin Islands batholith, British Virgin Islands . Master thesis. University of North Carolina at Chapel Hill, Chapel Hill, NC December 2010, Chapter II: Background, p. 4–10 , doi : 10.17615 / b0qw-pr21 (English).
  5. ↑ Kevin Lee Schrecengost: Geochemistry and U / Pb zircon geochronology of the Virgin Islands batholith, British Virgin Islands . Master thesis. University of North Carolina at Chapel Hill, Chapel Hill, NC December 2010, Chapter IV: Results - U-Pb zircon geochronology, p. 30 , doi : 10.17615 / b0qw-pr21 (English).
  6. ↑ Floyd Gray et al .: Porphyry copper assessment of Central America and the Caribbean Basin (= Michael L. Zientek [Hrsg.]: Global mineral resource assessment . Chapter I). United States Geological Survey, February 28, 2014, ISSN  2328-0328 , Appendix A. Porphyry Copper Assessment for Tract 003pCu4001 (CA_CARIBKT1), Santiago Region — Cuba, Dominican Republic, Haiti, Jamaica, Puerto Rico, and the Virgin Islands: Copper Occurrences in the Virgin Islands, S. 33 , doi : 10.3133 / sir20105090I (English).
  7. ↑ Dennis P. Cox et al .: Potassium-argon geochronology of some metamorphic, igneous, and hydrothermal events in Puerto Rico and the Virgin Islands US Geological Survey . In: Journal of Research of the US Geological Survey . tape 5 , no. 6 , November 1977, ISSN  0091-374X , p. 689–703 , here p. 701: “Virgin Islands Batholith” , doi : 10.3133 / 70007423 (English).
  8. ↑ a b c GC1B1J1 Copper Point Mine (Earthcache). In: Geocaching. Groundspeak , accessed on March 16, 2020 .
  9. ^ A b c d Edward L. Towle et al .: Virgin Gorda Natural Resources Survey: A review of selected economic development possibilities and constraints . Island Resources Foundation, St. Thomas, USVI March 15, 1976, Chapter 7. Mining: 7.1. Virgin Gorda Copper Mine, p. 76-77 (English, irf.org [PDF; 6.1 MB ; retrieved on March 16, 2020] partially dubious data: the indication of the distance between the soles [stopes] only makes sense if "fathoms" are replaced by "feet", and the year the mine was closed is given by all recent sources as 1862) .
  10. ↑ a b c d e f g h i Sue Appleby: The Cornish in the Caribbean: From the 17th to the 19th Centuries . Matador, Kibworth Beauchamp, Leicestershire 2019, ISBN 978-1-78901-713-7 , 9: Copper and Guano: The Mines of Virgin Gorda and Sombrero, pp. 233–255 (English, limited preview in Google Book Search).
  11. ↑ Trey Ratcliff: Behind the Scenes - Abandoned Copper Mine in Virgin Gorda. Video. In: YouTube . May 8, 2012, accessed on March 16, 2020 (the section from 4:40 to 7:28 is of interest here).
  12. ↑ a b c d The Copper Mine. In: The British Virgin Islands. BVI Tourist Board, accessed on March 16, 2020 .
  13. ^ A b Sue Appleby: The Cornish in the Caribbean: From the 17th to the 19th Centuries . Matador, Kibworth Beauchamp, Leicestershire 2019, ISBN 978-1-78901-713-7 , Appendix 9: Background History of Virgin Gorda, pp. 297–300 (English, limited preview in Google Book Search).
  14. ↑ a b c Michael Kent: An Environmental Profile of the Island of Virgin Gorda, British Virgin Islands, including Eustatia, Mosquito, Necker, Prickly Pear, Saba Rock, The Dog Islands, Broken Jerusalem, Fallen Jerusalem, Round Rock . Island Resources Foundation, Tortola, BVI / Washington, DC 2012, 6.2.1 The Copper Mine, p. 154–155 (English, irf.org [PDF; 15.0 MB ; accessed on March 16, 2020]).
  15. ^ A b Dedication of the Copper Mine National Park Visitor Center. Video from the opening ceremony of the visitor center. In: bvi.gov.vg. Government of the Virgin Islands, January 27, 2017, accessed on March 16, 2020 (in English, an informative tour of the exhibition and the mine site takes place from around 36:45).
  16. ↑ National Parks Ready to Receive Guests. Press release. In: bvi.gov.vg. Government of the Virgin Islands, December 7, 2017, accessed March 16, 2020 .
  17. ↑ Michael Kent: An Environmental Profile of the Island of Virgin Gorda, British Virgin Islands, including Eustatia, Mosquito, Necker, Prickly Pear, Saba Rock, The Dog Islands, Broken Jerusalem, Fallen Jerusalem, Round Rock . Island Resources Foundation, Tortola, BVI / Washington, DC 2012, 6.2.2 Beam Engine Lever, Copper Mine Bay, p. 154–155 (English, irf.org [PDF; 15.0 MB ; accessed on March 16, 2020]).
  18. ^ Copper Mine Point, Virgin Gorda, British Virgin Islands. In: mindat.org. Hudson Institute of Mineralogy, accessed March 16, 2020 .