Gold prospecting is the act of searching for new gold deposits. Methods used vary with the type of deposit sought and the resources of the prospector. Although traditionally a commercial activity, in some developed countries placer gold prospecting has also become a popular outdoor recreation. Gold prospecting has been popular since antiquity. From the earliest textual and archaeological references, gold prospecting was a common thread for gaining wealth.
Prospecting for placer gold is normally done with a gold pan or similar instrument to wash free gold particles from loose surface sediment. [1] The use of gold pans is centuries old, but is still common among prospectors and miners with little financial backing.
Deeper placer deposits may be sampled by trenching or drilling. [2] Geophysical methods such as seismic, gravity or magnetics may be used to locate buried river channels that are likely locations for placer gold. [3] Sampling and assaying a placer gold deposit to determine its economic viability is subject to many pitfalls. [4]
Once placer gold is discovered, the gold pan is usually replaced by sluices or mechanical devices to wash greater volumes of material. Discovery of placer gold has often resulted in discovery of hardrock gold deposits when the placers are traced to their sources.
Prospectors for hardrock, or lode gold deposits, can use many tools. It is done at the simplest level by surface examination of rock outcrops, looking for exposures of mineral veins, hydrothermal alteration, or rock types known to host gold deposits. Field tools may be nothing more than a rock hammer and hand lens.
Hardrock gold deposits are more varied in mineralogy and geology than placer deposits, and prospecting methods can be very different for different types of deposits. As with placer gold, the sophistication of methods used to prospect for hardrock gold vary with the financial resources of the prospector. Drilling is often used to explore the subsurface. Surface geophysical methods may be used to locate geophysical anomalies associated with gold deposits. Samples of rocks or soil may be collected for geochemical laboratory assay, to determine metal content or detect geochemical anomalies. [5] Hardrock gold particles may be too small to see, even with a microscope.
Most gold today is produced in large open-pit and deep underground mines. However, small-scale gold mining is still common, especially in developing countries.
A 2012 study by Australian scientists found that termites have been found to excrete trace deposits of gold. According to the CSIRO, the termites burrow beneath eroded subterranean material which typically masks human attempts to find gold, and ingest and bring the new deposits to the surface. They believe that studying termite nests may lead to less invasive methods of finding gold deposits. [6] [7] [8] Herodotus reported about gold-digging ants.
Small-scale recreational prospecting for placer gold has been seen in many parts of the world including New Zealand (especially in Otago), Australia, South Africa, Wales (at Dolaucothi and in Gwynedd), in Canada and in the United States especially in western states but also elsewhere.
Placer mining is the mining of stream bed (alluvial) deposits for minerals. This may be done by open-pit or by various surface excavating equipment or tunneling equipment.
Mining in the engineering discipline is the extraction of minerals from underneath, open pit, above, or on the ground. Mining engineering is associated with many other disciplines, such as mineral processing, exploration, excavation, geology, and metallurgy, geotechnical engineering and surveying. A mining engineer may manage any phase of mining operations, from exploration and discovery of the mineral resources, through feasibility study, mine design, development of plans, production and operations to mine closure.[citation needed]
Gold panning, or simply panning, is a form of placer mining and traditional mining that extracts gold from a placer deposit using a pan. The process is one of the simplest ways to extract gold, and is popular with geology enthusiasts especially because of its low cost and relative simplicity.
Prospecting is the first stage of the geological analysis of a territory. It is the search for minerals, fossils, precious metals, or mineral specimens. It is also known as fossicking.
The Dolaucothi Gold Mines, also known as the Ogofau Gold Mine, are ancient Roman surface and underground mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales. The gold mines are located within the Dolaucothi Estate, which is owned by the National Trust.
Botanical prospecting for uranium is a method of finding uranium deposits either by observation of plant life growing on the surface, or by geochemical analysis of plant material in a process known as Geobotanical prospecting.
Geobotanical prospecting refers to prospecting based on indicator plants like metallophytes and the analysis of vegetation. The concept is speculative or even fringe science. Sitings of commercial mines are invariably guided by geological principles and confirmed by chemical assays.
In the United States, gold mining has taken place continually since the discovery of gold at the Reed farm in North Carolina in 1799. The first documented occurrence of gold was in Virginia in 1782. Some minor gold production took place in North Carolina as early as 1793, but created no excitement. The discovery on the Reed farm in 1799 which was identified as gold in 1802 and subsequently mined marked the first commercial production.
Gold mining in Alaska, a state of the United States, has been a major industry and impetus for exploration and settlement since a few years after the United States acquired the territory in 1867 from the Russian Empire. Russian explorers discovered placer gold in the Kenai River in 1848, but no gold was produced. Gold mining started in 1870 from placers southeast of Juneau, Alaska.
Gold was discovered in the Yentna-Cache Creek Mining District in the U.S. state of Alaska of the upper Susitna River Valley in 1898, soon followed by claim staking. Placer mining was reported in the Cache Creek drainage of the Dutch Hills by 1906. Quaternary glaciofluvial deposits, alluvial deposits, and Cenozoic conglomeratic white quartz-breccia units have been mined in the Dutch Hills. About 200,000 oz of gold has been produced from these placer deposits. By 1927, a road from Talkeetna was constructed into the mining area, known today as The Petersville Road. The mining camp of Petersville, Alaska served as the area Post Office for several years in the late 1920s and early 1930s. Two areas have been set aside for recreational gold mining, the North and South units of the Petersville State Recreation Mining Areas. Many smaller one-man and family placer mining operations continue today.
The Ruby–Poorman mining district in the U.S. state of Alaska produced nearly a half million ounces of gold, all from placer mines. Some of the largest gold nuggets found in Alaska are from the district, which lies along the Yukon River. The placers are mostly deeply buried, and most were originally worked with shafts and drifts. Dozens of creeks in the district were mined, many more bear gold prospects. Cassiterite, platinum, scheelite, allanite, and native bismuth have been recovered along with gold from placer mines in the district.
The Nome mining district, also known as the Cape Nome mining district, is a gold mining district in the U.S. state of Alaska. It was discovered in 1898 when Erik Lindblom, Jafet Lindeberg and John Brynteson, the "Three Lucky Swedes", found placer gold deposits on Anvil Creek and on the Snake River few miles from the future site of Nome. Word of the strike caused a major gold rush to Nome in the spring of 1899.
The following outline is provided as an overview of and topical guide to mining:
Recreational gold mining and prospecting has become a popular outdoor recreation in a number of countries, including New Zealand, Australia, South Africa, Wales, in Canada and in the United States especially. Recreational mining is often small-scale placer mining but has been challenged for environmental reasons. The disruption of old gold placer deposits risks the reintroduction of post gold rush pollution, including mercury in old mining deposits and mine tailings.
Stoping is the process of extracting the desired ore or other mineral from an underground mine, leaving behind an open space known as a stope. Stoping is used when the country rock is sufficiently strong not to collapse into the stope, although in most cases artificial support is also provided.
The Batu Hijau mine is an open pit copper-gold mine operated by PT. Amman Mineral Nusa Tenggara. The mine is the second largest copper-gold mine in Indonesia behind the Grasberg mine of PT. Freeport Indonesia. The mine is located 1,530 kilometres (950 mi) east of the Indonesian capital Jakarta on Sumbawa, an island in West Nusa Tenggara Province, more precisely in the southern part of West Sumbawa Regency. The mine is the result of a ten-year exploration and construction program based on a 1999 discovery of the porphyry copper deposit. Production began in 2000.
Beanland Mine, also known as Clenor Mine, is an abandoned surface and underground mine in Northeastern Ontario, Canada. It is located about 1 km (0.62 mi) west of Arsenic Lake and 4 km (2.5 mi) northwest of the town of Temagami in central Strathy Township. It is named after Sydney Beanland, who first claimed the mine site in the 1920s and was a director for the mine from 1937 to 1938.
Orex Exploration is a former Canadian gold mining company that conducted exploration work on mining properties it owned in the Goldboro and Guysborough County areas of Nova Scotia. The properties owned by Orex were the sites of the former Boston Richardson Mine, Dolliver Mountain Mine, West Goldbrook Mine, and East Goldbrook Mine which operated between 1892 and 1912. Headquartered in Rouyn-Noranda, Quebec, the company was founded in 1987 and raised funds for exploration work, in part, by issuing stocks traded on the Montreal Stock Exchange and then the TSX Venture Exchange. It became a subsidiary of Anaconda Mining Inc. after Anaconda acquired the company in a stock swap deal in 2017.
Dan Hausel a polymath of martial arts, geology, writing, astronomy, art, and public speaking. Hall-of-Fame 10th degree black belt grandmaster of Shorin-Ryu Karate and Kobudo, mineral exploration geologist who made several gold, colored gemstone, and diamond deposit discoveries in Alaska, Colorado, Montana and Wyoming, author of more than 600 publications including books, maps, professional papers and magazine articles, public speaker, artist, former astronomy lecturer for the Hansen Planetarium in Utah, and former rock musician.
The Omai Gold Mine is located in Guyana on the north coast of South America near the west bank of the Essequibo River in the interior of the country. Access to Omai is by road from the capital of Georgetown on the coast, and from the town of Linden approximately 60 km away. There is an operational airstrip on site which can accommodate aircraft from Georgetown. Gold mining at Omai is known from at least the 1880s, and when it was developed as a large scale mine in 1992 by Cambior, the mine was the largest gold mine in the Guiana Shield and a major source of income and employment in Guyana. During the period from 1992 – 2005, Omai produced 3.7 Moz of gold at an average grade of 1.5 g/t Au from the Fennell and the Wenot open pits.