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Broken Ridge
The Broken Ridge or Broken Plateau is an oceanic plateau in the south-eastern Indian Ocean. The Broken Ridge once formed a large igneous province (LIP) together with the Kerguelen Plateau. When Australia and Antarctica started to separate, the Broken Ridge and the Kerguelen Plateau got separated by the Southeast Indian Ridge. Alkalic basalt from the Broken Ridge has been dated to 95 Ma. The Broken Ridge stretches from the southern end of the Ninety East Ridge towards the south-western corner of Australia. It is up to wide and reaches below sea level. It is separated from the Diamantina fracture zone on its southern side by a escarpment, while on the northern side the ridge slopes gently towards the abyssal Wharton Basin. The sediment cover on the ridge reaches and the Moho is found at about . It is separated from the Naturaliste Plateau by the Dirck Hartog Ridge. The Kerguelen LIP covered making it the second largest LIP on Earth (after the Ontong Java Plateau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seir
Seir or SEIR may refer to: *Mount Seir, a mountainous region stretching between the Dead Sea and the Gulf of Aqaba *Seir the Horite, chief of the Horites, a people mentioned in the Torah *Sa'ir, also Seir, a Palestinian town in the Hebron Governorate in the West Bank *Seir, a List of demons in the Ars Goetia#Seere, demon in the ''Ars Goetia'' *Southeast Indian Ridge (SEIR), is a mid-ocean ridge in the southern Indian Ocean *SEIR model, a Compartmental models in epidemiology, compartmental model in epidemiology *Single-engine instrument rating, an aircraft pilot qualification See also *Sear (other) *Sere (other) *Osiris, an Egyptian god *Sah (god), in Egyptian mythology the deification of the constellation Orion *Seri people, an indigenous group of the Mexican state of Sonora {{disambiguation, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naturaliste Plateau
The Naturaliste Plateau is one of several large submarine plateaus extending from Western Australia into the Indian Ocean. It is a rectilinear plateau that covers an area of 90,000 square kilometres. Its width is about east-west and north-south. The water depths are from 1500 to 5000 metres. The Mentelle Basin and Naturaliste Trough lie between the mainland and this plateau. The plateau is bordered by the Perth Abyssal Plain in the north and west and the Australian–Antarctic Basin in the south.Naturaliste Plateau: Regional setting . Geoscience Australia. It is located within the Australian marine park known as the South-west Corner Marine Park. The Naturaliste Plateau formed during the Early Cretaceous 136 Ma when Australia and I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Igneous Provinces
A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including intrusive ( sills, dikes) and extrusive (lava flows, tephra deposits), arising when magma travels through the crust towards the surface. The formation of LIPs is variously attributed to mantle plumes or to processes associated with divergent plate tectonics. The formation of some of the LIPs in the past 500 million years coincide in time with mass extinctions and rapid climatic changes, which has led to numerous hypotheses about causal relationships. LIPs are fundamentally different from any other currently active volcanoes or volcanic systems. Overview Definition In 1992, Coffin and Eldholm initially defined the term "large igneous province" as representing a variety of mafic igneous provinces with areal extent greater than 100,000 km2 that represented "massive crustal emplacements of predominantly mafic (magnesium- and iron-rich) extrusive and intrusive rock, and origina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamprophyre
Lamprophyres () are uncommon, small-volume ultrapotassic igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks, and small intrusions. They are alkaline silica- undersaturated mafic or ultramafic rocks with high magnesium oxide, >3% potassium oxide, high sodium oxide, and high nickel and chromium. Lamprophyres occur throughout all geologic eras. Archaean examples are commonly associated with lode gold deposits. Cenozoic examples include magnesian rocks in Mexico and South America, and young ultramafic lamprophyres from Gympie in Australia with 18.5% MgO at ~250 Ma. Petrology Modern science treats lamprophyres as a catch-all term for ultrapotassic mafic igneous rocks which have primary mineralogy consisting of amphibole or biotite, and with feldspar in the groundmass. Lamprophyres are not amenable to classification according to modal proportions, such as the system QAPF, because of their peculiar mineralogy, nor compositional discrimination diagrams, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rajmahal Traps
The Rajmahal Traps is a volcanic igneous province in Eastern India, covering the parts of Jharkhand, West Bengal and Meghalaya. The Rajmahal Hills of Jharkhand is the type area of this province. Multiple layers of solidified lava made the Rajmahal Traps which are dipping 2–5° towards the north-east. Individual layers vary in thickness from less than to more than . Genesis These volcanic rocks were formed from the eruptions over the Kerguelen hotspot in the early Cretaceous. Courtillot, Vincent. ''Evolutionary Catastrophes: The Science of Mass Extinctions.'' Cambridge, Cambridge University Press, 1999; p. 95. The similarity between the geochemical data of Rajmahal volcanos and lavas of the Kerguelen Plateau confirms this. According to plate tectonics, the Indian subcontinent was over this hot spot during the Cretaceous Period. The original lava flow covered an area of nearly . Below the Bengal basin the flows cover .{{cite journal, last=Singh, first=A. P., author2=Niraj ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bunbury Basalt
Bunbury may refer to: Places * Bunbury, South Australia * Bunbury, Western Australia ** Bunbury (suburb) ** Bunbury port, in Vittoria, Western Australia ** Bunbury Airport ** City of Bunbury, the local government area ** Electoral district of Bunbury * Bunbury, Cheshire, England People * Bunbury (surname) * Bunbury baronets * Enrique Bunbury, Spanish singer professionally goes by Bunbury Arts and entertainment * Bunbury, a fictional character in Oscar Wilde's comedy ''The Importance of Being Earnest'' * Bunbury, a fictional place in the Quadling Country of L. Frank Baum's Land of Oz * The Bunburys, a short-lived supergroup including Eric Clapton and the Bee Gees * Bunbury Music Festival The Bunbury Music Festival was a three-day music festival in Cincinnati, Ohio, United States, at Sawyer Point Park & Yeatman's Cove on the banks of the Ohio River. Each annual event typically featured over 100 acts performing on three to six se ..., in Cincinnati, Ohio, U.S. Other uses * HMA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diapir
A diapir (; , ) is a type of intrusion in which a more mobile and ductilely deformable material is forced into brittle overlying rocks. Depending on the tectonic environment, diapirs can range from idealized mushroom-shaped Rayleigh–Taylor instability structures in regions with low tectonic stress such as in the Gulf of Mexico to narrow dikes of material that move along tectonically induced fractures in surrounding rock. The term was introduced by Romanian geologist Ludovic Mrazek, who was the first to understand the principle of salt tectonics and plasticity. The term ''diapir'' may be applied to '' igneous intrusions'', but it is more commonly applied to non-igneous, relatively cold materials, such as salt domes and mud diapirs. If a salt diapir reaches the surface, it can flow because salt becomes ductile with a small amount of moisture, forming a salt glacier. Occurrence Differential loading causes salt deposits covered by overburden (sediment) to rise upward tow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerguelen Hotspot
The Kerguelen hotspot is a volcanic hotspot at the Kerguelen Plateau in the Southern Indian Ocean. The Kerguelen hotspot has produced basaltic lava for about 130 million years and has also produced the Kerguelen Islands, Naturaliste Plateau, Heard Island, the McDonald Islands, the Comei large igneous province in south Tibet, and the Rajmahal Traps. One of the associated features, the Ninety East Ridge, is distinguished by its over length, being the longest linear tectonic feature on Earth. The total volume of magma erupted in 130 million years with associated features has been estimated to be about . However, as well as large igneous provinces and seamounts the hotspot has interacted with other seafloor spreading features, so this volume figure has some uncertainty. Recent Volcanism The most recent activity of the Kerguelen hotspot has been near Heard Island and McDonald Islands where there are two active volcanoes, but its current location could be quite a wide area of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ontong Java Plateau
The Ontong Java Plateau (OJP) is a massive oceanic plateau located in the southwestern Pacific Ocean, north of the Solomon Islands. The OJP was formed around (Ma), with a much smaller volcanic event around 90 Ma. Two other southwestern Pacific plateaus, Manihiki and Hikurangi, now separated from the OJP by Cretaceous oceanic basins, are of similar age and composition and probably formed as a single plateau and a contiguous large igneous province together with the OJP. When eruption of lava had finished, the Ontong Java–Manihiki–Hikurangi plateau covered 1% of Earth's surface and represented a volume of of basaltic magma. This "Ontong Java event", first proposed in 1991, represents the largest volcanic event of the past 200 million years, with a magma eruption rate estimated at up to per year over 3 million years, for a total several times larger than the Deccan Traps. The smooth surface of the OJP is punctuated by seamounts such as the Ontong Java Atoll, one of the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirck Hartog Ridge
Dirck is a given name. Notable people with the name include: *Dirck Barendsz (1534–1592), Dutch Renaissance painter from Amsterdam *Dirck Bleker (1621–1702), Dutch Golden Age painter *Dirck Coornhert (1522–1590), Dutch writer, philosopher, translator, politician and theologian *Dirck Cornelis de Hooch (1613–1651), 17th-century Dutch portrait painter *Dirck de Bray (1635–1694), Dutch Golden Age painter * Dirck Ferreris (1639–1693), Dutch Golden Age painter *Dirck Gerritsz Pomp (1544–1608), Dutch sailor, the first known Dutchman to visit Japan *Dirck Hals (1591–1656), Dutch painter of festivals and ballroom scenes *Dirck Halstead, (born 1936), photojournalist, and editor and publisher of ''The Digital Journalist'' *Dirck Helmbreker (1633–1696), Dutch Golden Age painter of Italianate landscapes * Dirck Jacobsz. (1496–1567), Dutch Renaissance painter *Dirck Pesser (1585–1651), Dutch brewer from Rotterdam *Dirck Rembrantsz van Nierop (1610–1682), Dutch cartograph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mohorovičić Discontinuity
The Mohorovičić discontinuity ( ; )usually called the Moho discontinuity, Moho boundary, or just Mohois the boundary between the Earth's crust, crust and the Earth's mantle, mantle of Earth. It is defined by the distinct change in velocity of seismic waves as they pass through changing densities of rock. The Moho lies almost entirely within the lithosphere (the hard outer layer of the Earth, including the crust). Only beneath mid-ocean ridges does it define the lithosphere–asthenosphere boundary (the depth at which the mantle becomes significantly ductile). The Mohorovičić discontinuity is below the ocean floor, and beneath typical continental crusts, with an average of . Named after the pioneering Croats, Croatian seismologist Andrija Mohorovičić, the Moho separates both the oceanic crust and continental crust from the underlying mantle. The Mohorovičić discontinuity was first identified in 1909 by Mohorovičić, when he observed that seismograms from Depth of focus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Plateau
An oceanic or submarine plateau is a large, relatively flat elevation that is higher than the surrounding relief with one or more relatively steep sides. There are 184 oceanic plateaus in the world, covering an area of or about 5.11% of the oceans. The South Pacific region around Australia and New Zealand contains the greatest number of oceanic plateaus (see map). Oceanic plateaus produced by large igneous provinces are often associated with hotspot (geology), hotspots, mantle plumes, and volcanic islands — such as Iceland, Hawaii, Cape Verde, and Kerguelen. The three largest plateaus, the Caribbean large igneous province, Caribbean, Ontong Java Plateau, Ontong Java, and Mid-Pacific Mountains, are located on swell (geology), thermal swells. Other oceanic plateaus, however, are made of rifted continental crust, for example the Falkland Plateau, Lord Howe Rise, and parts of Kerguelen Plateau, Kerguelen, Mascarene Plateau, Seychelles, and Arctic ridges. Plateaus formed by larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
