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Ellendale Diamond Field
The Ellendale Diamond Field is a cluster of diamond producing lamproite intrusions located 125 km ESE of Derby within the WNW trending Lennard Shelf to the south of the Kimberley Block in the West Kimberly region of Australia. Ellendale's volcanic lamproite pipes intruded during the Miocene age between 22 and 19 Ma, and 48 lamproites have been mapped within the northwest-trending 1500-square-kilometre (60 x 25 km) field. More than 100 lamproite intrusions are known over a wider 7500 km2 area surrounding the Ellendale swarm. Some 45 of the Ellendale intrusives are volcanic crater deposits, while 3 are classed as volcanic sills. The lamproites are either leucite or olivine rich, with 60% being diamondiferous. The first Ellendale pipe was identified in 1976 with diamonds mostly mined from 2 open pit hard-rock mines at the Ellendale 4 (E4) and Ellendale 9 (E9) lamproite pipes. Although of low grade (5 to 14 carats per hundred ton), these mines were characterised by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kimberley (Western Australia)
The Kimberley is the northernmost of the nine regions of Western Australia. It is bordered on the west by the Indian Ocean, on the north by the Timor Sea, on the south by the Great Sandy Desert, Great Sandy and Tanami Desert, Tanami deserts in the region of the Pilbara, and on the east by the Northern Territory. The region was named in 1879 by government surveyor Alexander Forrest after Secretary of State for the Colonies John Wodehouse, 1st Earl of Kimberley. History The Kimberley was one of the earliest settled parts of Australia, with the first humans landing about 65,000 years ago. They created a complex culture that developed over thousands of years. Yam (vegetable), Yam (''Dioscorea hastifolia'') agriculture was developed, and rock art suggests that this was where some of the earliest boomerangs were invented. The worship of Wandjina deities was most common in this region, and a complex theology dealing with the transmigration of souls was part of the local people's religi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamproite
Lamproite is an ultrapotassic mantle-derived volcanic or subvolcanic rock. It has low CaO, Al2O3, Na2O, high K2O/Al2O3, a relatively high MgO content and extreme enrichment in incompatible elements. Lamproites are geographically widespread yet are volumetrically insignificant. Unlike kimberlites, which are found exclusively in Archaean cratons, lamproites are found in terrains of varying age, ranging from Archaean in Western Australia, to Palaeozoic and Mesozoic in southern Spain. They also vary widely in age, from Proterozoic to Pleistocene, the youngest known example from Gaussberg in Antarctica being 56,000 ± 5,000 years old. Lamproite volcanology is varied, with both diatreme styles and cinder cone or cone edifices known. Petrology Lamproites form from partially melted mantle at depths exceeding 150 km. The molten material is forced to the surface in volcanic pipes, bringing with it xenoliths and diamonds from the harzburgitic peridotite or eclogite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derby, Western Australia
Derby ( ) is a town in the Kimberley region of Western Australia. At the 2016 census, Derby had a population of 3,325 with 47.2% of Aboriginal and Torres Strait Islander descent. Along with Broome and Kununurra, it is one of only three towns in the Kimberley to have a population over 2,000. Located on King Sound, Derby has the highest tides in Australia, with the differential between low and high tide reaching .Derby tides at derbytourism.com.au . Retrieved 7 January 2007 History Derby falls within Nyiginka country. The town was founded in 1883 and named after |
West Kimberley
West Kimberley is a sub region of the Kimberley region of Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust .... The region is defined according to different purposes. The area has been listed as a heritage area. Related to the heritage listing, the area has had portions that have been omitted due to extant mining leases. The name is also included in the current local government name of Shire of Derby-West Kimberley, which was known earlier as the West Kimberley Road Board. References {{WesternAustralia-geo-stub Kimberley (Western Australia) Australian National Heritage List ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene followed the Oligocene and preceded the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing the connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and Ape, hominoids into Eurasia. During the late Miocene, the conn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leucite
Leucite (from the Greek word ''leukos'' meaning white) is a rock-forming mineral of the feldspathoid group, silica-undersaturated and composed of potassium and aluminium tectosilicate KAlSi2O6. Crystals have the form of cubic icositetrahedra but, as first observed by Sir David Brewster in 1821, they are not optically isotropic, and are therefore pseudo-cubic. Goniometric measurements made by Gerhard vom Rath in 1873 led him to refer the crystals to the tetragonal system. Optical investigations have since proved the crystals to be still more complex in character, and to consist of several orthorhombic or monoclinic individuals, which are optically biaxial and repeatedly twinned, giving rise to twin-lamellae and to striations on the faces. When the crystals are raised to a temperature of about 500 °C they become optically isotropic and the twin-lamellae and striations disappear, although they reappear when the crystals are cooled again. This pseudo-cubic character of le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olivine
The mineral olivine () is a magnesium iron Silicate minerals, silicate with the chemical formula . It is a type of Nesosilicates, nesosilicate or orthosilicate. The primary component of the Earth's upper mantle (Earth), upper mantle, it is a common mineral in Earth's subsurface, but weathers quickly on the surface. Olivine has many uses, such as the gemstone peridot (or chrysolite), as well as industrial applications like metalworking processes. The ratio of magnesium to iron varies between the two endmember (mineralogy), endmembers of the solid solution series: forsterite (Mg-endmember: ) and fayalite (Fe-endmember: ). Compositions of olivine are commonly expressed as Mole (unit), molar percentages of forsterite (Fo) and/or fayalite (Fa) (''e.g.'', Fo70Fa30, or just Fo70 with Fa30 implied). Forsterite's melting temperature is unusually high at atmospheric pressure, almost , while fayalite's is much lower – about . Melting temperature varies smoothly between the two end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kimberlite
Kimberlite is an igneous rock and a rare variant of peridotite. It is most commonly known as the main host matrix for diamonds. It is named after the town of Kimberley, Northern Cape, Kimberley in South Africa, where the discovery of an 83.5-Carat (mass), carat (16.70 g) diamond called the Star of South Africa (diamond), 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. Kimberlite occurs in the Earth's Crust (geology), crust in vertical structures known as Volcanic pipe, kimberlite pipes, as well as igneous Dike (geology), dykes and can also occur as horizontal Sill (geology), sills. Kimberlite pipes are the most important source of mined diamonds today. The consensus on kimberlites is that they are formed deep within Earth's mantle. Formation occurs at depths between 150 and 450 kilometres ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argyle Diamond Mine
The Argyle Diamond Mine was a diamond mine located in the East Kimberley region in the remote north of Western Australia. Argyle was at times the largest diamond producer in the world by volume (14 million carats in 2018), although the proportion of gem-quality diamonds was low. It was the only known significant source of pink and red diamonds (producing over 90% of the world's supply), and additionally provided a large proportion of other naturally coloured diamonds, including champagne, cognac and rare blue diamonds. Mining operations ceased in November 2020, after 37 years of operations and producing more than 865 million carats of rough diamonds. Mine operator Rio Tinto plans to decommission the mine and rehabilitate the site at least through 2025. The Argyle diamond mine is also notable for being the first successful commercial diamond mine exploiting a volcanic pipe of lamproite, rather than the more usual kimberlite pipe; much earlier attempts to mine diamonds from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maureen Muggeridge
Maureen Muggeridge (13 August 1948 – 7 October 2010) was a British geologist best known for discovering the Argyle diamond deposit in the north of Western Australia. Early life and education Muggeridge was born in Croydon; her father was Eric Muggeridge, the founder of the charity Plan International. She spent the majority of her childhood in Cameroon and was later sent back to England to a convent school in Sussex. Later, she became a day pupil at Brighton and Hove High School. Career After graduating in Geology from the University of St Andrews, she made her way to Perth, Western Australia, with support from her family. Within a week she got a job with a mining company called Tanganyika Holdings and was flying over the Outback searching for diamonds. Tanganyika Holdings was involved in a joint venture with other companies. In 1976, minerals were found which suggested the presence of diamonds. A joint venture was set up with CRA Exploration which they called the Ashton Jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond
Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond is 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 Chemical stability, chemically stable form of carbon at Standard temperature and pressure, room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest Scratch hardness, hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Small numbers of lattice defect, defects or impurities (about one per million of lattice atoms) can color ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Mines In Australia
Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond is 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. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Small numbers of defects or impurities (about one per million of lattice atoms) can color a diamond blue (boron), yellow (nitrogen), brown (defects), green (radiation exposure), purple, pink, oran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
