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Kiruna is the northernmost town in Sweden, situated in the province of Lapland. It had 17,002 inhabitants in 2016 and is the seat of Kiruna Municipality in Norrbotten County. The city was originally built in the 1890s to serve the Kiruna Mine.
The Witwatersrand is a 56-kilometre-long (35 mi), north-facing scarp in South Africa. It consists of a hard, erosion-resistant quartzite metamorphic rock, over which several north-flowing rivers form waterfalls, which account for the name Witwatersrand, meaning "ridge of white waters" in Afrikaans. This east-west-running scarp can be traced with only one short gap, from Bedfordview in the east, through Johannesburg and Roodepoort, to Krugersdorp in the west.
Conglomerate is a clastic sedimentary rock that is composed of a substantial fraction of rounded to subangular gravel-size clasts. A conglomerate typically contain a matrix of finer grained sediments, such as sand, silt, or clay, which fills the interstices between the clasts. The clasts and matrix are typically cemented by calcium carbonate, iron oxide, silica, or hardened clay.
Ringing rocks, also known as sonorous rocks or lithophonic rocks, are rocks that resonate like a bell when struck, such as the Musical Stones of Skiddaw in the English Lake District; the stones in Ringing Rocks Park, in Upper Black Eddy, Bucks County, Pennsylvania; the Ringing Rocks of Kiandra, New South Wales; and the Bell Rock Range of Western Australia. Ringing rocks are used in idiophonic musical instruments called lithophones.
The Isua Greenstone Belt is an Archean greenstone belt in southwestern Greenland. The belt is aged between 3.7 and 3.8 billion years. The belt contains variably metamorphosed mafic volcanic and sedimentary rocks. The occurrence of boninitic geochemical signatures, characterized by extreme depletion in trace elements that are not fluid mobile, offers evidence that plate tectonic processes in which lithic crust is melted may have been responsible for the creation of the belt. Another theory posits that the belt formed via a process known as vertical plate tectonics.
Grängesberg is a locality situated in Ludvika Municipality, Dalarna County, Sweden, with 3,481 inhabitants in 2010.
Svappavaara is a locality situated in Kiruna Municipality, Norrbotten County, Sweden with 417 inhabitants in 2010. It is a mining village. Mining was started around 1650. Large scale iron mining started in 1965. The mine was closed in 1983, but enrichment of iron ore from the mine at Kiruna is still going on. The mine is owned by LKAB, and there is an ongoing project to open it again for production around year 2015.
Iron oxide copper gold ore deposits (IOCG) are important and highly valuable concentrations of copper, gold and uranium ores hosted within iron oxide dominant gangue assemblages which share a common genetic origin.
The Kiruna mine is the largest and most modern underground iron ore mine in the world. The mine is located in Kiruna in Norrbotten County, Lapland, Sweden. The mine is owned by Luossavaara-Kiirunavaara AB (LKAB), a large Swedish mining company. In 2018 the mine produced 26.9 million tonnes of iron ore. The Kiruna mine has an ore body which is 4 km (2.5 mi) long, 80 metres (260 ft) to 120 metres (390 ft) thick and reaching a depth of up to 2 km (1.2 mi). Since mining began at the site in 1898, the mine has produced over 950 million tonnes of ore.
The Atacama Fault Zone (AFZ) is an extensive system of faults cutting across the Chilean Coastal Cordillera in Northern Chile between the Andean Mountain range and the Pacific Ocean. The fault system is North-South striking and runs for more than 1100 km North and up to 50 km in width through the Andean forearc region. The zone is a direct result of the ongoing subduction of the Eastward moving Nazca Plate beneath the South American Plate and is believed to have formed in the Early Jurassic during the beginnings of the Andean orogeny. The zone can be split into 3 regions: the North, Central and South.
El Laco is a volcanic complex in the Antofagasta Region of Chile. It is directly south of the Cordón de Puntas Negras volcanic chain. Part of the Central Volcanic Zone of the Andes, it is a group of seven stratovolcanoes and a caldera. It is about two million years old. The main summit of the volcano is a lava dome called Pico Laco, which is variously reported to be 5,325 metres (17,470 ft) or 5,472 metres (17,953 ft) high. The edifice has been affected by glaciation, and some reports indicate that it is still fumarolically active.
The Fig Tree Formation, also called Fig Tree Group, is a stromatolite-containing geological formation in South Africa. The rock contains fossils of microscopic life forms of about 3.26 billion years old. Identified organisms include the bacterium Eobacterium isolatus and the algae-like Archaeosphaeroides barbertonensis. The fossils in the Fig Tree Formation are considered some of the oldest known organisms on Earth, and provide evidence that life may have existed much earlier than previously thought. The formation is composed of shales, turbiditic greywackes, volcaniclastic sandstones, chert, turbiditic siltstone, conglomerate, breccias, mudstones, and iron-rich shales.
The Catoctin Formation is a geologic formation that expands through Virginia, Maryland, and Pennsylvania. It dates back to the Precambrian and is closely associated with the Harpers Formation, Weverton Formation, and the Loudoun Formation. The Catoctin Formation lies over the a granite basement rock and below the Chilhowee Group making it only exposed on the outer parts of the Blue Ridge. The Catoctin Formation contains metabasalt, metarhyolite, and porphyritic rocks, columnar jointing, low-dipping primary joints, amygdules, sedimentary dikes, and flow breccias. Evidence for past volcanic activity includes columnar basalts and greenstone dikes.
The geology of the Republic of the Congo, also known as Congo-Brazzaville, to differentiate from the Democratic Republic of the Congo, formerly Zaire, includes extensive igneous and metamorphic basement rock, some up to two billion years old and sedimentary rocks formed within the past 250 million years. Much of the country's geology is hidden by sediments formed in the past 2.5 million years of the Quaternary.
The geology of Liberia is largely extremely ancient rock formed between 3.5 billion and 541 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 Sierra Leone is primarily very ancient Precambrian Archean and Proterozoic crystalline igneous and metamorphic basement rock, in many cases more than 2.5 billion years old. Throughout Earth history, Sierra Leone was impacted by major tectonic and climatic events, such as the Leonean, Liberian and Pan-African orogeny mountain building events, the Neoproterozoic Snowball Earth and millions of years of weathering, which has produced thick layers of regolith across much of the country's surface.
The geology of Sweden is the regional study of rocks, minerals, tectonics, natural resources and groundwater in the country. The oldest rocks in Sweden date to more than 2.5 billion years ago in the Precambrian. Complex orogeny mountain building events and other tectonic occurrences built up extensive metamorphic crystalline basement rock that often contains valuable metal deposits throughout much of the country. Metamorphism continued into the Paleozoic after the Snowball Earth glaciation as the continent Baltica collided with an island arc and then the continent Laurentia. Sedimentary rocks are most common in southern Sweden with thick sequences from the last 250 million years underlying Malmö and older marine sedimentary rocks forming the surface of Gotland.
The Chilean Iron Belt is a geological province rich in iron ore deposits in northern Chile. It extends as a north-south beld along the western part of the Chilean regions of Coquimbo and Atacama, chiefly between the cities of La Serena and Taltal. The belt follows much of the Atacama Fault System and is about 600 km long and 25 km broad.
Kiruna porphyry is a group of igneous rocks found near Kiruna in northernmost Sweden. The Kiruna Porphyry formed 1,880 to 1,900 million years ago during the Paleoproterozoic Era in connection to the Svecofennian orogeny.
Hauki quartzite is a rock unit of quartz arenite found in northernmost Sweden. More arkosic parts are of reddish colour but otherwise made of light grey rocks. Apart from quart arenite the unit hosts some conglomerates with clasts of phyllite and quartz porphyry. The clasts are derived from the nearby units of Hopukka Formation, Loussavaara Formation and Matojärvi Formation.
References
- 1 2 3 4 5 Offerberg, Jan (1967). Beskrivning till berggrundskartbladen Kiruna NV, NO, SV, SO (in Swedish). Stockholm: Sveriges Geologiska Undersökning. pp. 34–36.
- 1 2 Andersson, J.B., Bauer, T.E., & Martinsson, O. (2021). Structural Evolution of the Central Kiruna Area, Northern Norrbotten, Sweden: Implications on the Geologic Setting Generating Iron Oxide-Apatite and Epigenetic Iron and Copper Sulfides. Economic Geology .