What are the main rock forming minerals found in Merensky Reef?
The rock-forming silicate minerals of the Merensky Reef consist predominantly of orthopyroxene (∼ 60 per cent), plagioclase feldspar (∼ 20 per cent), pyroxene (∼ 15 per cent), phlogopite (5 per cent), and occasional olivine, see Table I, which lists the composition of some of the common minerals found in the Bushveld- …
How was the Bushveld Complex formed?
Origin and formation
Vast quantities of molten rock from Earth’s mantle were brought to the surface through long vertical cracks in Earth’s crust—huge arcuate differentiated lopolithic intrusions—creating the geological intrusion known as the Bushveld Igneous Complex.
How is chromitite formed?
Chromitite layers are common in large mafic layered intrusions. A widely accepted hypothesis holds that the chromitites formed as a consequence of injection and mixing of a chemically relatively primitive magma into a chamber occupied by more evolved magma.
What is UG2?
SYNOPSIS. The Upper Group 2 (UG2) chromitite reef is a shallow-dipping stratiform tabular orebody in the South African Bushveld Complex, which strikes for hundreds of kilometres. Mining is extensive, with depths ranging from close-to-surface to 2 500 m. Pillars are widely used to support the open stopes and bords.
What is the difference between Merensky & UG2?
The UG2 Reef, the composition of which is relatively consistent throughout the BIC, is rich in chromite. However, the UG2 Reef lacks the Merensky’s gold, copper and nickel by-products, though its reserves may be almost twice those of the Merensky Reef.
What rocks are formed from coral reefs?
limestone
The type of rock that the coral skeletons build is called limestone. Limestone has been forming in Earth’s oceans for more than 400 million years. Limestone deposits that began as coral reefs provide evidence of how Earth’s surface and environment has changed.
What type of rock is Bushveld Complex?
igneous rocks
The Bushveld Complex consists of coarse-grained igneous rocks with a wide range of composition from ultramafic to felsic. It is temporally, and possibly genetically, related to volcanic rocks of the Rooiberg Group (Cawthorn et al., 2007) (Figure 1).
What does the Bushveld mean?
Definition of bushveld
: veld of southern Africa with abundant shrubby and often thorny vegetation.
How is Hedenbergite formed?
Cordua.) Description: Hedenbergite is a dark green to black member of the pyroxene group. It usually forms due to metamorphism of iron-rich or carbonate-rich sedimentary rocks or as a primary mineral in certain syenites and related rocks.
What is meant by ore grade?
The grade of ore refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining, and is therefore considered an ore.
What does Hans Merensky do?
Hans Merensky (16 March 1871 – 21 October 1952) was a South African geologist, prospector, scientist, conservationist and philanthropist.
What is chromite used for?
Chromite is the main source of the metal chromium, a metal used to induce hardness, toughness and chemical resistance in steel.
What are the 4 types of coral reefs?
Scientists generally agree on four different coral reef classifications: fringing reefs, barrier reefs, atolls, and patch reefs. Fringing reefs grow near the coastline around islands and continents. They are separated from the shore by narrow, shallow lagoons. Fringing reefs are the most common type of reef.
What is coral reef made of?
Coral reefs are massive structures made of limestone deposited by coral polyps. Often referred to as the “rainforests of the sea,” coral reefs support approximately 25 percent of all known marine species.
What do Bushveld Minerals do?
Through Vametco and Vanchem, Bushveld Minerals produces Nitro Vanadium, ferrovanadium, vanadium oxides and vanadium chemicals, delivering a diversified revenue stream from the steel, chemicals and energy storage markets.
What is bushveld ecosystem?
The bushveld (“thornbush field”) is characterized by trees—acacia and baobab as well as thornbushes—and tall grasses. It is moderately dry, with annual rainfall of about 15–25 inches (380–640 mm). Herding is the principal economic activity; large-scale cultivation is possible only in irrigated areas.
Where is Hedenbergite found?
Locality: Nordmark, Sweden. Name Origin: Named after the Swedish mineralogist, M. A. L. Hedenberg.
What is the colour of pyroxene?
Identification: Pyroxenes typically occur as stubby prismatic crystals. They are generally dark green to black in colour, though they can range from apple-green and lilac to colourless, depending on their chemical composition. Pyroxenes have a hardness between 5 and 7.
What are the four types of ore?
There are mainly four kinds of ores like Ores Oxides; Ores Carbonate; Sulphide Ores; Ores Halides.
What is a good ore grade?
For underground mining, the World Gold Council defines between 8 and 10 grams per tonne as ‘high-quality’, and 1 to 4 grams per tonne as ‘low-quality’. There is no exact definition of what is considered as high or low grade.
Who owns Hans Merensky?
A privately-held company, its shareholders include the Hans Merensky Foundation, the South African state-owned Industrial Development Corporation (IDC), International Finance Corporation (IFC), Vuka Forestry Holdings (Pty) Limited, Women Investment Portfolio Holdings (Pty) Limited and HMH staff.
What kind of mineral is chromite?
Chromite is a crystalline mineral composed primarily of iron(II) oxide and chromium(III) oxide compounds. It can be represented by the chemical formula of FeCr2O4. It is an oxide mineral belonging to the spinel group.
What mineral is chromite made of?
Chromite is an oxide mineral that an iron chromium oxide with formula: FeCr2O4. It is belonging to the spinel group. Chromite is the most important ore of chromium. Crystals are uncommon, but when found they are octahedral.
What are the 2 main types of coral?
There are 2 main classifications for corals: 1. Hard coral (scleractinian and stony coral) which form reefs by a calcium carbonate base, with polyps with 6 stiff tentacles, and 2. Soft coral (Alcyonacea and ahermatypic coral) which are bendable and formed by a colony of polyps with 8 feather like tentacles.
What are the 3 main types of coral?
The three main types of coral reefs are fringing, barrier, and atoll. Schools of colorful pennantfish, pyramid, and milletseed butterflyfish live on an atoll reef in the Northwestern Hawaiian Islands. The most common type of reef is the fringing reef. This type of reef grows seaward directly from the shore.