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Meguma Terrane
The Meguma terrane, also known as Megumia, is a terrane exposed in southern Nova Scotia, that became joined to the present North American landmass as part of the Appalachian orogeny. The exposed part of the Meguma terrane, the Meguma Group, is largely composed of thick Cambrian to Ordovician turbidites that have been interpreted as submarine fan deposits. The Meguma terrane is joined to the Avalon terrane along the Minas Fault Zone, which runs east–west from Chedabucto Bay to Cobequid Bay and the Minas Basin. The Meguma Group is intruded by numerous Devonian and Carboniferous plutons. The extent of the formation is unclear; some geologists believe that a magnetic anomaly along the coast of Cape Cod may represent a suture between the Meguma and Avalon terranes in that region. Unlike the Avalon terrane, the Meguma terrane has not been definitely associated with a territory on the other side of the Atlantic. It may be represented in either the Galicia-Tras-Os-Montes Zone in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terranes Of Nova Scotia
In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its own distinctive geologic history, which is different from that of the surrounding areas—hence the term "exotic" terrane. The suture zone between a terrane and the crust it attaches to is usually identifiable as a fault. A sedimentary deposit that buries the contact of the terrane with adjacent rock is called an overlap formation. An igneous intrusion that has intruded and obscured the contact of a terrane with adjacent rock is called a stitching pluton. Older usage of ''terrane'' simply described a series of related rock formations or an area having a preponderance of a particular rock or rock groups. Overview A tectonostratigraphic terrane is not necessarily an independent microplate in origin, since it may not contain the full thickness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous
The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferous'' means "coal-bearing", from the Latin '' carbō'' ("coal") and '' ferō'' ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern 'system' names, it was coined by geologists William Conybeare and William Phillips in 1822, based on a study of the British rock succession. The Carboniferous is often treated in North America as two geological periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial animal life was well established by the Carboniferous Period. Tetrapods (four limbed vertebrates), which had originated from lobe-finned fish during the preceding Devonian, became pentadactylous in and diversified during the Carboniferous, including early amphibian line ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural History Of North America
Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are part of nature, human activity is often understood as a separate category from other natural phenomena. The word ''nature'' is borrowed from the Old French ''nature'' and is derived from the Latin word ''natura'', or "essential qualities, innate disposition", and in ancient times, literally meant "birth". In ancient philosophy, ''natura'' is mostly used as the Latin translation of the Greek word ''physis'' (φύσις), which originally related to the intrinsic characteristics of plants, animals, and other features of the world to develop of their own accord. The concept of nature as a whole, the physical universe, is one of several expansions of the original notion; it began with certain core applications of the word φύσις by pre-Socr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geography Of Nova Scotia
Nova Scotia is a province located in Eastern Canada fronting the Atlantic Ocean. One of the Maritime Provinces, Nova Scotia's geography is complex, despite its relatively small size in comparison to other Canadian provinces. Physical geography The mainland portion of the Nova Scotia peninsula is attached to North America through the Isthmus of Chignecto. Various offshore islands, the largest of which is Cape Breton Island, form the bulk of the eastern part of the province. The geological history of the province spans more than 1.2 billion year Continental drift led to the southern half of the province's mainland portion, the Meguma terrane, once being attached to Africa whereas the Avalon terrane comprising the northern half, including Cape Breton Island, was once attached to Scandinavia and Scotland. The Meguma terrane became joined to the present North American landmass as part of the Appalachian orogeny. Composed largely of Cambrian to Ordovician sedimentary deposits, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization's work spans the disciplines of biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility. The agency was founded on March 3, 1879. The USGS is a bureau of the United States Department of the Interior; it is that department's sole scientific agency. The USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, and Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on the occasion of its hundredt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental ( native state), as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroaurate anion. Gold is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous Period, it merged with Laurasia to form a larger supercontinent called Pangaea. Gondwana (and Pan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazonian Craton
The Amazonian Craton is a geologic province located in South America. It occupies a large portion of the central, north and eastern part of the continent and represents one of Earth's largest cratonic regions. The Guiana Shield and Central Brazil Shield (Guaporé Shield) constitute respectively the northern and southern exhumed parts of the craton. Between the two shields lies the Amazon Rift, a zone of weakness within the craton. Smaller cratons of Precambrian rocks south of the Amazonian Shield are the Río de la Plata Craton and the São Francisco Craton, which lies to the east. The Río Apa Craton at the Paraguay-Brazil border is considered be likely just the southern part of the Amazonian Craton. The rocks of Río Apa were deformed during the Sunsás orogeny. It has been suggested that the Late Mesoproterozoic– Early Neoproterozoic aged Sveconorwegian Orogen in Fennoscandia could have been caused by a continent–continent collision between the Amazonia and Balti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
West African Craton
The West African Craton (WAC) is one of the five cratons of the Precambrian basement rock of Africa that make up the African Plate, the others being the Kalahari craton, Congo craton, Saharan Metacraton and Tanzania Craton.Jessell M.W., Liégeois J-P. (2015). "100 years of research on the West African Craton". ''Journal of African Earth Sciences''. 112(B): 377– 381. Cratons themselves are tectonically inactive, but can occur near active margins,Ennih N. & Liégeois J-P. (2008). ''The Boundaries of the West African Craton''. Geological Society, London, Special Publications. 297: 1–17. with the WAC extending across 14 countries in Western Africa, coming together in the late Precambrian and early Palaeozoic eras to form the African continent. It consists of two Archean centers juxtaposed against multiple Paleoproterozoic domains made of greenstone belts, sedimentary basins, regional granitoid-tonalite-trondhjemite-granodiorite, tonalite-trondhjemite-granodiorite (TTG) plutons, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of The Iberian Peninsula
The geology of the Iberian Peninsula consists of the study of the rock formations on the Iberian Peninsula, which includes Spain, Portugal, Andorra, and Gibraltar. The peninsula contains rocks from every geological period from the Ediacaran to the Quaternary, and many types of rock are represented. World-class mineral deposits are also found there. The core of the Iberian Peninsula consists of a Hercynian cratonic block known as the Iberian Massif. On the northeast this is bounded by The Pyrenean fold belt, and on the southeast it is bounded by the Betic Fold mountain chain. These twofold chains are part of the Alpine belt. To the west, the peninsula is delimited by the continental boundary formed by the opening of the Atlantic Ocean. The Hercynian Fold belt is mostly buried by Mesozoic and Cenozoic cover rocks to the east, but nevertheless outcrops through the Iberian Chain and the Catalan Coastal Ranges. Iberian Massif The Iberian Massif consists of rocks from the Paleoz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Cod
Cape Cod is a peninsula extending into the Atlantic Ocean from the southeastern corner of mainland Massachusetts, in the northeastern United States. Its historic, maritime character and ample beaches attract heavy tourism during the summer months. The name Cape Cod, coined in 1602 by Bartholomew Gosnold, is the ninth oldest English place-name in the U.S. As defined by the Cape Cod Commission's enabling legislation, Cape Cod is conterminous with Barnstable County, Massachusetts. It extends from Provincetown in the northeast to Woods Hole in the southwest, and is bordered by Plymouth to the northwest. The Cape is divided into fifteen towns, several of which are in turn made up of multiple named villages. Cape Cod forms the southern boundary of the Gulf of Maine, which extends north-eastward to Nova Scotia. Since 1914, most of Cape Cod has been separated from the mainland by the Cape Cod Canal. The canal cuts roughly across the base of the peninsula, though small portions of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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