The Canadian Shield, also called the Laurentian Shield or the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks. It forms the North American Craton, the ancient geologic core of the North American continent. Glaciation has left the area with only a thin layer of soil, through which exposures of igneous bedrock resulting from its long volcanic history are frequently visible. As a deep, common, joined bedrock region in eastern and central Canada, the shield stretches north from the Great Lakes to the Arctic Ocean, covering over half of Canada and most of Greenland; it also extends south into the northern reaches of the continental United States.
Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond as a form of carbon is a tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of electricity, and insoluble in water. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. They are also the reason that diamond anvil cells can subject materials to pressures found deep in the Earth.
Garnets are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives.
Kimberlite, an igneous rock and a rare variant of peridotite, is most commonly known to be the main host matrix for diamonds. It is named after the town of Kimberley in South Africa, where the discovery of an 83.5-carat diamond called the Star of South Africa in 1869 spawned a diamond rush and led to the excavation of the open-pit mine called the Big Hole. Previously, the term kimberlite has been applied to olivine lamproites as Kimberlite II, however this has been in error.
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.
Amateur geology or rock collecting is the non-professional study and hobby of collecting rocks and minerals or fossil specimens from the natural environment. In Australia, New Zealand and Cornwall, the amateur geologists call this activity fossicking. The first amateur geologists were prospectors looking for valuable minerals and gemstones for commercial purposes. Eventually, however, more people have been drawn to amateur geology for recreational purposes, mainly for the beauty that rocks and minerals provide.
Diopside is a monoclinic pyroxene mineral with composition MgCaSi
2O
6. It forms complete solid solution series with hedenbergite and augite, and partial solid solutions with orthopyroxene and pigeonite. It forms variably colored, but typically dull green crystals in the monoclinic prismatic class. It has two distinct prismatic cleavages at 87 and 93° typical of the pyroxene series. It has a Mohs hardness of six, a Vickers hardness of 7.7 GPa at a load of 0.98 N, and a specific gravity of 3.25 to 3.55. It is transparent to translucent with indices of refraction of nα=1.663–1.699, nβ=1.671–1.705, and nγ=1.693–1.728. The optic angle is 58° to 63°.
Ultramafic rocks are igneous and meta-igneous rocks with a very low silica content, generally >18% MgO, high FeO, low potassium, and are usually composed of greater than 90% mafic minerals. The Earth's mantle is composed of ultramafic rocks. Ultrabasic is a more inclusive term that includes igneous rocks with low silica content that may not be extremely enriched in Fe and Mg, such as carbonatites and ultrapotassic igneous rocks.
Stewart Lynn "Stu" Blusson, is a Canadian businessman, geologist, investor, philanthropist, and prospector. He co-discovered the billion-dollar Ekati Diamond Mine, 300 kilometres from Yellowknife, Northwest Territories, Canada. He serves as President of Archon Minerals Ltd. In 2002, Blusson donated key start-up funds necessary for Quest University Canada in Squamish, British Columbia. In 2006, Blusson donated $10 million for the Archon X PRIZE to develop a quick and inexpensive way to sequence the human genome. Blusson had a net worth of $660 million CDN in 2006.
Uranium mining in Colorado, United States, goes back to 1872, when pitchblende ore was taken from gold mines near Central City, Colorado. The Colorado uranium industry has seen booms and busts, but continues to this day. Not counting byproduct uranium from phosphate, Colorado is considered to have the third largest uranium reserves of any US state, behind Wyoming and New Mexico.
Ralph Jackson Roberts (1911–2007) was an American geologist and research scientist with the USGS. He is credited with the discovery of the Carlin and Battle Mountain Gold Belts, which make up the richest gold-mining region in Nevada as well as the United States.
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.
The following outline is provided as an overview of and topical guide to mining:
The geology of Saskatchewan can be divided into two main geological regions, the Precambrian Canadian Shield and the Phanerozoic Western Canadian Sedimentary Basin. Within the Precambrian shield exists the Athabasca sedimentary basin. Meteorite impacts have altered the natural geological formation processes. The prairies were most recently affected by glacial events in the Quaternary period.
The Seminoe Mountains greenstone belt represents a fragment of an Archean greenstone terrane within the Wyoming craton. The greenstone belt was mapped by Hausel, who identified significant gold anomalies at Bradley Peak in banded iron formation, quartz veins and in a large altered zone of metabasalts. Mapping differentiated three mappable units that included the Bradley Peak metavolcanics, the Seminoe Formation and the Sunday Morning metasediments.
The Rattlesnake Hills greenstone belt represents a fragment of a partially exposed synformal Archean greenstone belt within the Wyoming craton that was intruded by Cenozoic alkalic volcanics. The supracrustal belt has been subjected to multiphase deformation during the Archean and later brittle deformation during the Laramide orogeny. Ductile deformation during the Archean produced foliation, and at least three episodes of folding.
The South Pass greenstone belt is located within the Wyoming Craton in the United States. The region was the site of Wyoming's initial gold discovery in 1842.
The Great Falls Tectonic Zone is a major intracontinental shear zone between the Hearne craton and Wyoming craton basement rock of the Archean Eon which form part of the North American continent. The zone is an area about 100 miles wide extending from the southwestern Idaho-Montana border across Montana to the northwestern Montana-Saskatchewan-North Dakota border. It is named for the Great Falls of the Missouri River, a major geologic feature of the area. The central and western portions of the zone are believed to be about 1.1 to 3.3 billion years old. The central part of the zone lacks Archean rock, however, leading at least one group of scientists to speculate that it was formed very late in the Paleoproterozoic Era.
The geology of Liberia is largely extremely ancient rock formed between 3.5 billion and 539 million years ago in the Archean and the Neoproterozoic, with some rocks from the past 145 million years near the coast. The country has rich iron resources as well as some diamonds, gold and other minerals in ancient sediment formations weathered to higher concentrations by tropical rainfall.
The geology of Ghana is primarily very ancient crystalline basement rock, volcanic belts and sedimentary basins, affected by periods of igneous activity and two major orogeny mountain building events. Aside from modern sediments and some rocks formed within the past 541 million years of the Phanerozoic Eon, along the coast, many of the rocks in Ghana formed close to one billion years ago or older leading to five different types of gold deposit formation, which gave the region its former name Gold Coast.
