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Blake River Megacaldera Complex
The Blake River Megacaldera Complex is a giant subaqueous caldera cluster or a nested caldera system that spans across the Ontario–Quebec border in Canada. The caldera complex is around 2.7 billion years old, consisting of a series of overlapping calderas of various ages and sizes. It lies within the southern zone of the Abitibi greenstone belt of the Superior Craton and has an area of . The Blake River Megacaldera Complex has been a centre of major interest since 2006 with numerous excursions at the international, national and local level.ASH FALL: Newsletter of the Volcanology and Igneous Petrology Division Geological Association of Canada Retrieved on 2007-09-21 It is a world-class [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Misema Caldera
The Misema Caldera is a 2,704-2,707 million year old caldera in Ontario and Quebec, Canada. Geographic extent It is the caldera that forms the Blake River Megacaldera Complex Retrieved on 2007-09-24 and has a diameter of 40-80 kilometres. Composition The caldera is also a coalescence of at least two large es that formed more than 2703 million years ago.[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mafic
A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include basalt, diabase and gabbro. Mafic rocks often also contain calcium-rich varieties of plagioclase feldspar. Mafic materials can also be described as ferromagnesian. History The term ''mafic'' is a portmanteau of "magnesium" and "ferric" and was coined by Charles Whitman Cross, Joseph P. Iddings, Louis V. Pirsson, and Henry Stephens Washington in 1912. Cross' group had previously divided the major rock-forming minerals found in igneous rocks into ''salic'' minerals, such as quartz, feldspars, or feldspathoids, and ''femic'' minerals, such as olivine and pyroxene. However, micas and aluminium-rich amphiboles were excluded, while some calcium minerals containing little iron or magnesium, such as wollastonite or apatite, were included in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Volcanoes In Canada
List of volcanoes in Canada is an incomplete list of volcanoes found in Geography of Canada, mainland Canada, in the Islands of Canada, Canadian islands and in Canadian waters. All but two Provinces of Canada, provinces, Prince Edward Island and Manitoba, have at least one volcano. Alberta British Columbia New Brunswick Newfoundland and Labrador Northwest Territories Nova Scotia Nunavut Ontario Quebec Saskatchewan Yukon See also * Outline of Canada * Bibliography of Canada * Index of Canada-related articles * Volcanism of Canada ** Volcanism of Northern Canada ** Volcanism of Western Canada ** Volcanism of Eastern Canada ** List of Northern Cordilleran volcanoes * List of mountains in Canada * List of Cascade volcanoes External links Catalogue of Canadian Volcanoes {{Canadian volcanism Volcanoes of Canada, Lists of volcanoes, Canada Lists of mountains of Canada, Volcanoes Lists of landforms of Canada, Volcanoes Canada geology-related li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars
Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmospheric pressure is a few thousandths of Earth's, atmospheric temperature ranges from and cosmic radiation is high. Mars retains some water, in the ground as well as thinly in the atmosphere, forming cirrus clouds, frost, larger polar regions of permafrost and ice caps (with seasonal snow), but no liquid surface water. Its surface gravity is roughly a third of Earth's or double that of the Moon. It is half as wide as Earth or twice the Moon, with a diameter of , and has a surface area the size of all the dry land of Earth. Fine dust is prevalent across the surface and the atmosphere, being picked up and spread at the low Martian gravity even by the weak wind of the tenuous atmosphere. The terrain of Mars roughly follows a north-south ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olympus Mons
Olympus Mons (; ) is a large shield volcano on Mars. It is over high as measured by the Mars Orbiter Laser Altimeter (MOLA), about 2.5 times the elevation of Mount Everest above sea level. It is Mars's tallest volcano, its tallest planetary mountain, and is approximately tied with Rheasilvia on Vesta as the tallest mountain currently discovered in the Solar System. It is associated with the volcanic region of Tharsis Montes. It last erupted 25 million years ago. Olympus Mons is the youngest of the large volcanoes on Mars, having formed during the Martian Hesperian Period with eruptions continuing well into the Amazonian Period. It has been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for "Olympic Snow"), and its mountainous nature was suspected well before space probes confirmed it as a mountain. Two impact craters on Olympus Mons have been assigned provisional names by the International Astronomical Union: the Karzok crater a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guinea, Indonesia is the world's largest archipelagic state and the List of countries and dependencies by area, 14th-largest country by area, at . With over 280 million people, Indonesia is the world's List of countries and dependencies by population, fourth-most-populous country and the most populous Islam by country, Muslim-majority country. Java, the world's List of islands by population, most populous island, is home to more than half of the country's population. Indonesia operates as a Presidential system, presidential republic with an elected People's Consultative Assembly, legislature and consists of Provinces of Indonesia, 38 provinces, nine of which have Autonomous administrative divisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Toba
Lake Toba (, Toba Batak: ᯖᯀᯬ ᯖᯬᯅ; romanized: ''Tao Toba'') is a large natural lake in North Sumatra, Indonesia, occupying the caldera of the Toba supervolcano. The lake is located in the middle of the northern part of the island of Sumatra, with a surface elevation of about , the lake stretches from to . The lake is about long, wide, and up to deep. It is the largest lake in Indonesia and the largest volcanic lake in the world. Toba Caldera is one of twenty geoparks in Indonesia, and was recognised in July 2020 as one of the UNESCO Global Geoparks. Lake Toba is the site of a supervolcanic eruption estimated at VEI 8 that occurred 69,000 to 77,000 years ago, representing a climate-changing event. Recent advances in dating methods suggest a more accurate eruption date of 74,000 years ago. It is the largest-known explosive eruption on Earth in the last 25 million years. According to the Toba catastrophe theory, the eruption had global consequences for human po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wyoming
Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the south. With an estimated population of 587,618 as of 2024, Wyoming is the List of U.S. states and territories by population, least populous state despite being the List of U.S. states and territories by area, 10th largest by area, and it has the List of U.S. states by population density, second-lowest population density after Alaska. The List of capitals in the United States, state capital and List of municipalities in Wyoming, most populous city is Cheyenne, Wyoming, Cheyenne, which had a population of 65,132 in 2020. Wyoming's western half consists mostly of the ranges and rangelands of the Rocky Mountains; its eastern half consists of high-elevation prairie, and is referred to as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellowstone Caldera
The Yellowstone Caldera, also known as the Yellowstone Plateau Volcanic Field, is a Quaternary caldera complex and volcanic plateau spanning parts of Wyoming, Idaho, and Montana. It is driven by the Yellowstone hotspot and is largely within Yellowstone National Park. The field comprises four overlapping calderas, multiple lava domes, resurgent domes, crater lakes, and numerous bimodal lavas and tuffs of basaltic and rhyolitic composition, originally covering about . Volcanism began 2.15 million years ago and proceeded through three major volcanic cycles. Each cycle involved a large ignimbrite eruption, continental-scale ash-fall, and caldera collapse, preceded and followed by smaller lava flows and tuffs. The first and also the largest cycle was the Huckleberry Ridge Tuff eruption about 2.08 million years ago, which formed the Island Park Caldera. The most recent supereruption, about 0.63 million years ago, produced the Lava Creek Tuff and created the present Yellowsto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dike (geology)
In geology, a dike or dyke is a sheet of rock that is formed in a fracture of a pre-existing rock body. Dikes can be either magmatic or sedimentary in origin. Magmatic dikes form when magma flows into a crack then solidifies as a sheet intrusion, either cutting across layers of rock or through a contiguous mass of rock. Clastic dikes are formed when sediment fills a pre-existing crack.Essentials of Geology, 3rd Ed, Stephen Marshak Magmatic dikes A magmatic dike is a sheet of igneous rock that cuts across older rock beds. It is formed when magma fills a fracture in the older beds and then cools and solidifies. The dike rock is usually more resistant to weathering than the surrounding rock, so that erosion exposes the dike as a natural wall or ridge. It is from these natural walls that dikes get their name. Dikes preserve a record of the fissures through which most mafic magma (fluid magma low in silica) reaches the surface. They are studied by geologists for the clues they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supervolcano
A supervolcano is a volcano that has had an eruption with a volcanic explosivity index (VEI) of 8, the largest recorded value on the index. This means the volume of deposits for such an eruption is greater than . Supervolcanoes occur when magma in the mantle rises into the crust but is unable to break through it. Pressure builds in a large and growing magma pool until the crust is unable to contain the pressure and ruptures. This can occur at hotspots (for example, Yellowstone Caldera) or at subduction zones (for example, Toba). Large-volume supervolcanic eruptions are also often associated with large igneous provinces, which can cover huge areas with lava and volcanic ash. These can cause long-lasting climate change (such as the triggering of a small ice age) and threaten species with extinction. The Oruanui eruption of New Zealand's Taupō Volcano (about 25,600 years ago) was the world's most recent VEI-8 eruption. Terminology The term "supervolcano" was f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Lake
Lava lakes are large volumes of molten lava, usually basaltic, contained in a volcanic vent, crater, or broad depression. The term is used to describe both lava lakes that are wholly or partly molten and those that are solidified (sometimes referred to as ''frozen lava lakes''). Formation Lava lakes can form in three ways: *from one or more vents in a crater that erupts enough lava to partially fill the crater; or *when lava pours into a crater or broad depression and partially fills the crater; or *atop a new vent that erupts lava continuously for a period of several weeks or more and slowly builds a crater progressively higher than the surrounding ground. Behaviors Lava lakes occur in a variety of volcanic systems, ranging from the basaltic Erta Ale lake in Ethiopia and the basaltic andesite volcano of Villarrica, Chile, to the unique phonolitic lava lake at Mt. Erebus, Antarctica. Lava lakes have been observed to exhibit a range of behaviours. A "constantly circu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
