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58-545: Researchers have divided the Superior Craton into many different domains based on rock types and deformation styles. These domains (grouped into western and eastern superior provinces), include the North Superior Superterrane and Wawa Terrane, among others (shown in the table below). Studies on the formation of the Superior Craton varied in progress between the western and the eastern part. For

116-442: A convergent plate margin when plate motion compresses the margin. An orogenic belt or orogen develops as the compressed plate crumples and is uplifted to form one or more mountain ranges . This involves a series of geological processes collectively called orogenesis . These include both structural deformation of existing continental crust and the creation of new continental crust through volcanism . Magma rising in

174-732: A collisional orogeny). Orogeny typically produces orogenic belts or orogens , which are elongated regions of deformation bordering continental cratons (the stable interiors of continents). Young orogenic belts, in which subduction is still taking place, are characterized by frequent volcanic activity and earthquakes . Older orogenic belts are typically deeply eroded to expose displaced and deformed strata . These are often highly metamorphosed and include vast bodies of intrusive igneous rock called batholiths . Subduction zones consume oceanic crust , thicken lithosphere, and produce earthquakes and volcanoes. Not all subduction zones produce orogenic belts; mountain building takes place only when

232-506: A delamination of the orogenic root beneath them. Mount Rundle on the Trans-Canada Highway between Banff and Canmore provides a classic example of a mountain cut in dipping-layered rocks. Millions of years ago a collision caused an orogeny, forcing horizontal layers of an ancient ocean crust to be thrust up at an angle of 50–60°. That left Rundle with one sweeping, tree-lined smooth face, and one sharp, steep face where

290-589: A major continent-continent collision, is called an accretionary orogen. The North American Cordillera and the Lachlan Orogen of southeast Australia are examples of accretionary orogens. The orogeny may culminate with continental crust from the opposite side of the subducting oceanic plate arriving at the subduction zone. This ends subduction and transforms the accretional orogen into a Himalayan -type collisional orogen. The collisional orogeny may produce extremely high mountains, as has been taking place in

348-412: A noncollisional orogenic belt, and such belts are sometimes called Andean-type orogens . As subduction continues, island arcs , continental fragments , and oceanic material may gradually accrete onto the continental margin. This is one of the main mechanisms by which continents have grown. An orogen built of crustal fragments ( terranes ) accreted over a long period of time, without any indication of

406-442: A pronounced linear structure resulting in terranes or blocks of deformed rocks, separated generally by suture zones or dipping thrust faults . These thrust faults carry relatively thin slices of rock (which are called nappes or thrust sheets, and differ from tectonic plates ) from the core of the shortening orogen out toward the margins, and are intimately associated with folds and the development of metamorphism . Before

464-544: A series of sub-parallel thrust sheets, separated by major thrust faults. As the total shortening increases in a fold and thrust belt, the belt propagates into its foreland. New thrusts develop at the front of the belt, folding the older thrusts that have become inactive. This sequential propagation of thrusts into the foreland is the most common. Thrusts that form within the belt rather than at the thrust front are known as "out-of-sequence". In map view, fold and thrust belts are generally sinuous rather than completely linear. Where

522-450: Is a series of mountainous foothills adjacent to an orogenic belt , which forms due to contractional tectonics . Fold and thrust belts commonly form in the forelands adjacent to major orogens as deformation propagates outwards. Fold and thrust belts usually comprise both folds and thrust faults , commonly interrelated. They are commonly also known as thrust-and-fold belts, or simply thrust-fold belts. Fold and thrust belts are formed of

580-473: Is formed in a compression setting like crust collision. when the crust is compressed, thrusts dipping towards where the compression comes formed. The hanging walls of the thrusts slide up along the fault plane and stacks above the footwall, forming a ramp anticline or fault-bend fold . The Superior Province can be divided into three parts. The first part is the northwestern region characterized by high-grade gneiss , such as Minto and Pikwitonei. The second part

638-446: Is initiated along one or both of the continental margins of the ocean basin, producing a volcanic arc and possibly an Andean-type orogen along that continental margin. This produces deformation of the continental margins and possibly crustal thickening and mountain building. Mountain formation in orogens is largely a result of crustal thickening. The compressive forces produced by plate convergence result in pervasive deformation of

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696-555: Is significant as it involves the accretion of the younger Western Wabigoon terrane to the southwestern margin of the Winnipeg River Terrane. Two types of models were proposed to illustrate the process accretion with distinctive subduction polarity: Sanborn-Barrie and Skulski (2006) suggested that the accretion was achieved by the northeastward subduction of the Western Wabigoon Terrane underneath

754-422: Is still in use today, though commonly investigated by geochronology using radiometric dating. Based on available observations from the metamorphic differences in orogenic belts of Europe and North America, H. J. Zwart (1967) proposed three types of orogens in relationship to tectonic setting and style: Cordillerotype, Alpinotype, and Hercynotype. His proposal was revised by W. S. Pitcher in 1979 in terms of

812-480: Is taking place today in the Southern Alps of New Zealand). Orogens have a characteristic structure, though this shows considerable variation. A foreland basin forms ahead of the orogen due mainly to loading and resulting flexure of the lithosphere by the developing mountain belt. A typical foreland basin is subdivided into a wedge-top basin above the active orogenic wedge, the foredeep immediately beyond

870-746: Is the northeastern region, which is characterized by pervasive metamorphic rocks of granulite -facies. The last part is the southern region like the Minnesota River Valley , which are metavolcanic or metasedimentary subprovinces with an east–west orientation. The general geological characteristics of the terranes are listed below. - Mafic -intermediate volcanic rocks - Minor greywacke - Amphibolite -forming metamorphism caused by tectonic accretion - Diamond -containing kimberlite pipes - Volcaniclastic rocks (Oxford Lake assemblage) - Underlain by tonalitic , granodioritic , granitic pluton with mafic intrusion - Sealed

928-445: Is the region between the volcanic arc and the subduction zone. It includes several components, including the subduction trench , the outer arc high of the oceanic crust, the accretionary wedges , and the sedimentary basin . The outer arc high is formed by the flexural upward motion of the oceanic crust edge before it enters the subduction zone. The accretionary wedges are formed from the accumulation of marine sediment scraped off from

986-453: The Alpine type orogenic belt , typified by a flysch and molasse geometry to the sediments; ophiolite sequences, tholeiitic basalts, and a nappe style fold structure. In terms of recognising orogeny as an event , Leopold von Buch (1855) recognised that orogenies could be placed in time by bracketing between the youngest deformed rock and the oldest undeformed rock, a principle which

1044-640: The Himalayas for the last 65 million years. The processes of orogeny can take tens of millions of years and build mountains from what were once sedimentary basins . Activity along an orogenic belt can be extremely long-lived. For example, much of the basement underlying the United States belongs to the Transcontinental Proterozoic Provinces, which accreted to Laurentia (the ancient heart of North America) over

1102-716: The North American continent . Forming the core of the Canadian Shield , the Archean Superior craton is encompassed by early Proterozoic orogens . The western to the northeastern part of the craton is bound by the Trans-Hudson orogens . To the eastern and the southeastern side are the neighbouring Grenville orogens . The southern side meets the Keweenawan rift , while the southernmost tip of

1160-691: The San Andreas Fault , restraining bends result in regions of localized crustal shortening and mountain building without a plate-margin-wide orogeny. Hotspot volcanism results in the formation of isolated mountains and mountain chains that look as if they are not necessarily on present tectonic-plate boundaries, but they are essentially the product of plate tectonism. Likewise, uplift and erosion related to epeirogenesis (large-scale vertical motions of portions of continents without much associated folding, metamorphism, or deformation) can create local topographic highs. Eventually, seafloor spreading in

1218-647: The late Devonian (about 380 million years ago) with the Antler orogeny and continuing with the Sonoma orogeny and Sevier orogeny and culminating with the Laramide orogeny . The Laramide orogeny alone lasted 40 million years, from 75 million to 35 million years ago. Orogens show a great range of characteristics, but they may be broadly divided into collisional orogens and noncollisional orogens (Andean-type orogens). Collisional orogens can be further divided by whether

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1276-626: The North Kenyon Fault. The docking of the Northern Superior Superterrane is evident by the >3.5 Ga detrital zircons found in synorogenic (meaning that it forms during an orogenic event) sedimentary rocks aged <2.711 Ga. The docking also initiated the eruption of shoshonitic volcanic rocks during 2710 Ma and the regional shortening. The regional shortening had undergone folding and foliation to form right-lateral, NW-trending shear zones. During this period,

1334-632: The Northern Superior Superterrane and the North Caribou Terrane caused the southward drifting of the Northern Superior Superterrane. Over time, it united the North Caribou Superterrane and confined the Oxford-Stull domain, which contains rock assemblages related to the continental margin and oceanic crust. The combination of the Northern Superior Superterrane and the North Caribou Superterrane by subduction marked

1392-471: The Superior Craton in the past focused on how the western part formed. This leaves uncertainties in the linkage between the west and the east. The western Superior Craton is formed by different terranes stitching with each other continuously during the Neoarchean period. Such a progressive assembly can be explained by five discrete orogenies (mountain-building processes). They are, from the oldest event to

1450-503: The Winnipeg River Terrane at the south docked northward onto the North Caribou Terrane. The two terranes then sutured to form the English River belt, which was no earlier than <2705 Ma. During the orogeny, at the south-central North Caribou Superterrane, rocks were deformed thoroughly (from 2718 to 2712 Ma). After the deformation, plutons were emplaced in the area after the tectonic movements and cooled by about 2700 Ma. Following

1508-463: The Winnipeg River Terrane. This model is supported by evidence like the formation of the tonalitic and pyroclastic rocks in 2715-2700Ma and the deformation style of the Warclub turbidite assemblage which infers the over-riding of Winnipeg River Terrane on Western Wabigoon Terrane. Orogeny Orogeny ( / ɒ ˈ r ɒ dʒ ə n i / ) is a mountain - building process that takes place at

1566-497: The acceptance of plate tectonics , geologists had found evidence within many orogens of repeated cycles of deposition, deformation, crustal thickening and mountain building, and crustal thinning to form new depositional basins. These were named orogenic cycles , and various theories were proposed to explain them. Canadian geologist Tuzo Wilson first put forward a plate tectonic interpretation of orogenic cycles, now known as Wilson cycles. Wilson proposed that orogenic cycles represented

1624-414: The active front, a forebulge high of flexural origin and a back-bulge area beyond, although not all of these are present in all foreland-basin systems. The basin migrates with the orogenic front and early deposited foreland basin sediments become progressively involved in folding and thrusting. Sediments deposited in the foreland basin are mainly derived from the erosion of the actively uplifting rocks of

1682-635: The collision is with a second continent or a continental fragment or island arc. Repeated collisions of the later type, with no evidence of collision with a major continent or closure of an ocean basin, result in an accretionary orogen. Examples of orogens arising from collision of an island arc with a continent include Taiwan and the collision of Australia with the Banda arc. Orogens arising from continent-continent collisions can be divided into those involving ocean closure (Himalayan-type orogens) and those involving glancing collisions with no ocean basin closure (as

1740-476: The continental crust and melted into the mantle , which generated more magma . The huge amount of magma then rose up, penetrated through the crust above and erupted. The continuous eruption of volcanic material cooled down and accumulated around the centers of eruption, forming a chain of volcanoes in the shape of an arc. Some terranes, such as the Quetico Terrane, were forearcs in the past. A forearc

1798-635: The cooling of the pluton was the swift burial and melting of the rocks in the English River belt and Winnipeg River Terrane, as well as the overthrusting of the North Caribou Superterrane onto the English River Basin in a southward direction. Arc-related magmatic activities sustained in other areas of the southern North Caribou Superterrane margin at <2710 Ma. What was following is the deformation penetrative in both eastern (occurred at 2714-2702 Ma) and western (occurred at <2704 Ma) margins, followed by ductile-brittle faults. The Central Orogeny

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1856-596: The course of 200 million years in the Paleoproterozoic . The Yavapai and Mazatzal orogenies were peaks of orogenic activity during this time. These were part of an extended period of orogenic activity that included the Picuris orogeny and culminated in the Grenville orogeny , lasting at least 600 million years. A similar sequence of orogenies has taken place on the west coast of North America, beginning in

1914-653: The craton in Minnesota reaches the Central Plain orogen. Regarding the faults , there are three major trends of subparallel faults slicing the craton into linear subprovinces. In the northwestern part, faulting occurs in a west–northwest direction. The northeastern part has northwest-trending faults. The faults in the remaining southern part possess an east–west direction. The craton -forming terranes are created from very diverse settings, such as oceanic arc , ancient forearc , oceanic tectonic melange, uplift within

1972-538: The craton, fold-thrust belt and extra. Common among them is that these features were mostly formed in a compression setting. Some terranes, such as the Western Wabigoon Terrane, are formed from the setting of an oceanic arc. An oceanic arc is a chain of volcanoes which formed above and parallel to the subduction zones . Due to tectonic activities in the Earth, the relevant continental and oceanic crusts collided before 2.70 Ga. The denser oceanic crust subducted underneath

2030-427: The crust of the continental margin ( thrust tectonics ). This takes the form of folding of the ductile deeper crust and thrust faulting in the upper brittle crust. Crustal thickening raises mountains through the principle of isostasy . Isostacy is the balance of the downward gravitational force upon an upthrust mountain range (composed of light, continental crust material) and the buoyant upward forces exerted by

2088-575: The dense underlying mantle . Portions of orogens can also experience uplift as a result of delamination of the orogenic lithosphere , in which an unstable portion of cold lithospheric root drips down into the asthenospheric mantle, decreasing the density of the lithosphere and causing buoyant uplift. An example is the Sierra Nevada in California. This range of fault-block mountains experienced renewed uplift and abundant magmatism after

2146-754: The development of geologic concepts during the 19th century, the presence of marine fossils in mountains was explained in Christian contexts as a result of the Biblical Deluge . This was an extension of Neoplatonic thought, which influenced early Christian writers . The 13th-century Dominican scholar Albert the Great posited that, as erosion was known to occur, there must be some process whereby new mountains and other land-forms were thrust up, or else there would eventually be no land; he suggested that marine fossils in mountainsides must once have been at

2204-520: The edge of the uplifted layers are exposed. Although mountain building mostly takes place in orogens, a number of secondary mechanisms are capable of producing substantial mountain ranges. Areas that are rifting apart, such as mid-ocean ridges and the East African Rift , have mountains due to thermal buoyancy related to the hot mantle underneath them; this thermal buoyancy is known as dynamic topography . In strike-slip orogens, such as

2262-405: The effect of an active anorogenic magmatic activity. The Superior Craton covers central Canada; it occupies the northern and central part of Quebec, extending across the central and the southern part of Ontario, and also covers southeast Manitoba, with its tip reaching the boundary between the U.S. states of South Dakota and Minnesota. The Archean Superior Craton extends over 1572000 km of

2320-409: The final form of the majority of old orogenic belts is a long arcuate strip of crystalline metamorphic rocks sequentially below younger sediments which are thrust atop them and which dip away from the orogenic core. An orogen may be almost completely eroded away, and only recognizable by studying (old) rocks that bear traces of orogenesis. Orogens are usually long, thin, arcuate tracts of rock that have

2378-407: The initiation of the Superior Craton formation. The southward movement of the Northern Superior Superterrane to the North Caribou Superterrane driven by subduction activity is evident by a) arc-related magmatism in Oxford-Stull domain during 2775-2733 Ma; b) the south-over-north shearing zone at the contact between the two terranes. The suture zone of the subduction is inferred to be the margin of

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2436-543: The mountain range, although some sediments derive from the foreland. The fill of many such basins shows a change in time from deepwater marine ( flysch -style) through shallow water to continental ( molasse -style) sediments. While active orogens are found on the margins of present-day continents, older inactive orogenies, such as the Algoman , Penokean and Antler , are represented by deformed and metamorphosed rocks with sedimentary basins further inland. Long before

2494-416: The ocean basin comes to a halt, and continued subduction begins to close the ocean basin. The closure of the ocean basin ends with a continental collision and the associated Himalayan-type orogen. Erosion represents the final phase of the orogenic cycle. Erosion of overlying strata in orogenic belts, and isostatic adjustment to the removal of this overlying mass of rock, can bring deeply buried strata to

2552-583: The oceanic crust before it is subducted. The sedimentary basin is formed from the accumulation of erosive material from the volcanoes, which lying flatly between the volcanoes and the topographic high of the accretionary wedge. Some terranes, such as the Kapuskasing Uplift, were formed from the uplifting of the crustal block. For example, during 1.85 Ga, the American Midcontinent and the Superior Craton collided. The collision between

2610-462: The orogen carries less dense material upwards while leaving more dense material behind, resulting in compositional differentiation of Earth's lithosphere ( crust and uppermost mantle ). A synorogenic (or synkinematic ) process or event is one that occurs during an orogeny. The word orogeny comes from Ancient Greek ὄρος ( óros )  'mountain' and γένεσις ( génesis )  'creation, origin'. Although it

2668-416: The periodic opening and closing of an ocean basin, with each stage of the process leaving its characteristic record on the rocks of the orogen. The Wilson cycle begins when previously stable continental crust comes under tension from a shift in mantle convection . Continental rifting takes place, which thins the crust and creates basins in which sediments accumulate. As the basins deepen, the ocean invades

2726-518: The relationship to granite occurrences. Cawood et al. (2009) categorized orogenic belts into three types: accretionary, collisional, and intracratonic. Both accretionary and collisional orogens developed in converging plate margins. In contrast, Hercynotype orogens generally show similar features to intracratonic, intracontinental, extensional, and ultrahot orogens, all of which developed in continental detachment systems at converged plate margins. Fold and thrust belt A fold and thrust belt (FTB)

2784-441: The rift zone, and as the continental crust rifts completely apart, shallow marine sedimentation gives way to deep marine sedimentation on the thinned marginal crust of the two continents. As the two continents rift apart, seafloor spreading commences along the axis of a new ocean basin. Deep marine sediments continue to accumulate along the thinned continental margins, which are now passive margins . At some point, subduction

2842-491: The sea-floor. Orogeny was used by Amanz Gressly (1840) and Jules Thurmann (1854) as orogenic in terms of the creation of mountain elevations, as the term mountain building was still used to describe the processes. Elie de Beaumont (1852) used the evocative "Jaws of a Vise" theory to explain orogeny, but was more concerned with the height rather than the implicit structures created by and contained in orogenic belts. His theory essentially held that mountains were created by

2900-1477: The sediment after the collision of NSS and NCS - Pervasive granitic to tonalitic pluton in the central region - Rifting in the southern margin - Massive sulphide deposits - Amphibolite and low-pressure granulite - Migmatite and diatexite - Granite - Native silver deposits - Greenstone belts intruded by granitoid pluton in the East - Continental margin setting in the East - Metarsedimentary successions intruded by tonalite, nepheline , syenite , carbonatite and granite - Sanukitoids - Shebandowan-Schreiber belt (Fe, Au, VMS, Ni) - Central: Plutonic rocks and minor volcanic rocks - South: Younger greywackes, conglomerate and alkaline volcanic rocks - Central: Massive sulphide deposits and vein gold deposits - South: Gold deposits, Cu-Zn massive sulphide deposits, intrusive Ni deposits, and minor porphyry deposits - South: volcanic rocks - Gabbroic -sill-hosted Ni-Cu sulphide deposits - massive leucogranite intrusion - Granulite - Intrusion of diatexite, syenite, granodiorite and granite - komatiites - South: massive granodioritic complex - II: pyroxene -bearing plutonic rocks - IV: metasedimentary and pyroxene-bearing pluton - V: pyroxene-bearing pluton with minor tonalite - VI: magnetic pyroxene-bearing pluton - VII: tonalitic complex - Epigenetic: Cu, Ni, Ag, Au, rare earth elements (REE) and limited U deposits Research of

2958-414: The squeezing of certain rocks. Eduard Suess (1875) recognised the importance of horizontal movement of rocks. The concept of a precursor geosyncline or initial downward warping of the solid earth (Hall, 1859) prompted James Dwight Dana (1873) to include the concept of compression in the theories surrounding mountain-building. With hindsight, we can discount Dana's conjecture that this contraction

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3016-423: The subduction produces compression in the overriding plate. Whether subduction produces compression depends on such factors as the rate of plate convergence and the degree of coupling between the two plates, while the degree of coupling may in turn rely on such factors as the angle of subduction and rate of sedimentation in the oceanic trench associated with the subduction zone. The Andes Mountains are an example of

3074-460: The surface. The erosional process is called unroofing . Erosion inevitably removes much of the mountains, exposing the core or mountain roots ( metamorphic rocks brought to the surface from a depth of several kilometres). Isostatic movements may help such unroofing by balancing out the buoyancy of the evolving orogen. Scholars debate about the extent to which erosion modifies the patterns of tectonic deformation (see erosion and tectonics ). Thus,

3132-555: The two cratons triggered an Archean reverse fault , the Ivanhoe Lake fault. The upward movement of the hanging wall causes the uplift of a crustal block, known as the Kapuskasing Uplift. Some terranes, such as the Pontiac Terrane, were previously a fold-thrust belt . A fold-thrust belt is a zone consisting of a series of thrusts (reverse faults) and fault-bend folds separated by main thrust faults. The fold-thrust belt

3190-840: The western part, five major orogenies were involved. They include the Northern Superior Orogeny (2720 Ma ), the Uchian Orogeny (2720–2700 Ma), the Central Superior Orogeny (2700 Ma), the Shebandowanian Orogeny (2690 Ma), and the Minnesotan Orogeny (2680 Ma). For the eastern part, two models are suggested. The first model by Percival and Skulski (2000) focuses on the collision between the terranes . The second model by Bédard (2003) and Bédard et al. (2003) focuses on

3248-606: The youngest event, the Northern Superior Orogeny, the Uchian Orogeny, the Central Superior Orogeny, the Shebandowanian Orogeny and the Minnesotan Orogeny. These events show that the timeline of accretions starts from the north with a southward assembling direction. For these accretions, the North Caribou Terrane acted as the accretion nuclei onto which other terranes dock on its northern and southern side. Before 2720 Ma, there were many pieces of microcontinent fragments which E-W trending conduit-like ocean crusts (with unknown extent) separates them. During 2720 Ma, active subduction along

3306-399: Was due to the cooling of the Earth (aka the cooling Earth theory). The cooling Earth theory was the chief paradigm for most geologists until the 1960s. It was, in the context of orogeny, fiercely contested by proponents of vertical movements in the crust, or convection within the asthenosphere or mantle . Gustav Steinmann (1906) recognised different classes of orogenic belts, including

3364-499: Was used before him, the American geologist G. K. Gilbert used the term in 1890 to mean the process of mountain-building, as distinguished from epeirogeny . Orogeny takes place on the convergent margins of continents. The convergence may take the form of subduction (where a continent rides forcefully over an oceanic plate to form a noncollisional orogeny) or continental collision (convergence of two or more continents to form

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