Academic literature on the topic 'Regional orogenesis'
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Journal articles on the topic "Regional orogenesis"
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West Jr, David P., Charles V. Guidotti, and Daniel R. Lux. "Silurian orogenesis in the western Penobscot Bay region, Maine." Canadian Journal of Earth Sciences 32, no. 11 (November 1, 1995): 1845–58. http://dx.doi.org/10.1139/e95-142.
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New 40Ar/39Ar mineral ages from rocks collected west of Penobscot Bay, Maine, indicate this region was regionally deformed, metamorphosed to amphibolite facies conditions, and intruded by plutons in Silurian times rather than in the Devonian as previously assumed. Disturbed hornblende age spectra, along with the presence of some Devonian felsic plutons and extensive retrograde metamorphic textures do suggest, however, that these rocks were subsequently affected by low-grade Devonian thermal events. In sharp contrast, rocks west of the Sennebec Pond thrust fault, a major tectono-stratigraphic boundary in this region, lack a significant Silurian tectono-thermal signature, and instead record the effects of intense Devonian deformation and high-grade regional metamorphism. The data suggest the two regions experienced very different pre-Devonian histories and were most likely juxtaposed by the Sennebec Pond thrust fault in latest Silurian to Early Devonian time. Rocks now exposed east of the Sennebec Pond fault probably occupied much higher structural levels during Devonian orogenesis and were not subjected to the same intense Devonian deformation and metamorphism as those rocks now found to the west of this structure. The Silurian tectonism now recognized in this region bears striking resemblance to events of similar age recorded along the northwest margin of the Avalon composite terrane throughout much of Atlantic Canada. This greatly extends the zone of Silurian orogenesis in the northern Appalachians and requires that previous models of New England middle Paleozoic tectonism be significantly revised.
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Koulakov, I., I. Zabelina, I. Amanatashvili, and V. Meskhia. "Nature of orogenesis and volcanism in the Caucasus region based on results of regional tomography." Solid Earth Discussions 4, no. 1 (June 7, 2012): 641–62. http://dx.doi.org/10.5194/sed-4-641-2012.
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Abstract. In the paper we discuss the problem of continental collision and related volcanism in the Caucasus and surrounding areas based on analysis of the upper mantle seismic structure in a recently derived model by Koulakov (2011). This model, which includes P- and S-velocity anomalies down to 1000 km depth, was obtained from tomographic inversion of worldwide travel time data from the catalogue of the International Seismological Center. It can be seen that the Caucasus region is squeezed between two continental plates, Arabian to the south and European to the north, which are displayed in the tomographic model as high-velocity bodies down to about 200–250 km depth. On the contrary, a very bright low-velocity anomaly beneath the collision area implies that the lithosphere in this zone is very thin, which is also supported by strong deformations indicating weak properties of the lithosphere. In the contact between stable continental and collision zones we observe a rather complex alternation of seismic anomalies having the shapes of sinking drops. We propose that the convergence process causes crustal thickening and transformation of the lower crust material into the dense eclogite. When achieving a critical mass, the dense eclogitic drops trigger detachment of the mantle lithosphere and its delamination. The observed high-velocity bodies in the upper mantle may indicate the parts of the descending mantle lithosphere which were detached from the edges of the continental lithosphere plates. Very thin or even absent mantle part of the lithosphere leads to the presence of hot asthenosphere just below the crust. The crustal shortening and eclogitization of the lower crustal layer leads to the dominantly felsic composition of the crust which is favorable for the upward heat transport from the mantle. This, and also the factor of frictional heating, may cause to the origin of volcanic centers in the Caucasus and surrounding collisional areas.
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Koulakov, I., I. Zabelina, I. Amanatashvili, and V. Meskhia. "Nature of orogenesis and volcanism in the Caucasus region based on results of regional tomography." Solid Earth 3, no. 2 (October 17, 2012): 327–37. http://dx.doi.org/10.5194/se-3-327-2012.
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Abstract. In the paper, we discuss the problem of continental collision and related volcanism in the Caucasus and surrounding areas based on the analysis of the upper mantle seismic structure in a recently derived model by Koulakov (2011). This model, which includes P and S-velocity anomalies down to 1000 km depth, was obtained from tomographic inversion of worldwide travel time data from the catalogue of the International Seismological Center. It can be seen that the Caucasus region is squeezed between two continental plates, Arabian to the south and European to the north, which are displayed in the tomographic model as high-velocity bodies down to about 200–250 km depth. On the contrary, a very bright low-velocity anomaly beneath the collision area implies that the lithosphere in this zone is very thin, which is also supported by strong horizontal deformations and crustal thickening indicating weak properties of the lithosphere. In the contact between stable continental and collision zones, we observe a rather complex alternation of seismic anomalies having the shapes of sinking drops. We propose that the convergence process causes crustal thickening and transformation of the lower crust material into the dense eclogite. When achieving a critical mass, the dense eclogitic drops trigger detachment of the mantle lithosphere and its delamination. The observed high-velocity bodies in the upper mantle may indicate the parts of the descending mantle lithosphere which were detached from the edges of the continental lithosphere plates. Very thin, or even absent, mantle parts of the lithosphere leads to the presence of hot asthenosphere just below the crust. The crustal shortening and eclogitisation of the lower crustal layer leads to the dominantly felsic composition of the crust which is favourable for the upward heat transport from the mantle. This, and also the factors of frictional heating and the radioactivity of felsic rocks, may be the origin of volcanic centres in the Caucasus and surrounding collisional areas.
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Peacock, D. C. P. "The post-Variscan development of the British Isles within a regional transfer zone influenced by orogenesis." Journal of Structural Geology 26, no. 12 (December 2004): 2225–31. http://dx.doi.org/10.1016/j.jsg.2004.05.005.
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Lane, Larry S. "Devonian–Carboniferous paleogeography and orogenesis, northern Yukon and adjacent Arctic Alaska." Canadian Journal of Earth Sciences 44, no. 5 (May 1, 2007): 679–94. http://dx.doi.org/10.1139/e06-131.
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Surface and subsurface data from northern Yukon document a northward facies transition from shelf carbonates to basinal graptolitic shales and cherts from Late Cambrian to Early Devonian time. Parts of this north-facing continental margin were deformed during separate orogenic events of Early Devonian and Early Carboniferous ages. The first event, the Romanzof Orogeny, is identified in exposures across northwestern Yukon, in adjacent northeastern Alaska, and locally in the subsurface of the Alaska North Slope. It resulted in tight folds, north-directed thrust faults, and intrusion by Late Devonian posttectonic granitic plutons. Notwithstanding the thrust-fault orientations, southward diminution of deformation intensity combined with facies variations suggest that tectonic transport was generally southward. Evidence for an Early Carboniferous event is preserved in the northern Richardson Mountains and locally in the subsurface of the Mackenzie Delta region. It consists of detached open folds and minor thrust faults. Geological and geophysical data from northern Yukon document the location and orientation of the Early Carboniferous deformation front, and define a regional tectonic transport direction toward the south or southeast. This event is a distal foreland element of the Ellesmerian Orogeny (sensu stricto) of the Canadian Arctic Islands and is distinct from the Romanzof event in age, intensity, and extent. Endicott and Lisburne group strata, deposited on a southwest-facing subsiding shelf, overstep rocks deformed by the Romanzof event even as Ellesmerian deformation encroached from the north.
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Ford, Mary, Emmanuel Masini, Jaume Vergés, Raphael Pik, Sébastien Ternois, Julien Léger, Armin Dielforder, et al. "Evolution of a low convergence collisional orogen: a review of Pyrenean orogenesis." BSGF - Earth Sciences Bulletin 193 (2022): 19. http://dx.doi.org/10.1051/bsgf/2022018.
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The Pyrenees is a collisional orogen built by inversion of an immature rift system during convergence of the Iberian and European plates from Late Cretaceous to late Cenozoic. The full mountain belt consists of the pro-foreland southern Pyrenees and the retro-foreland northern Pyrenees, where the inverted lower Cretaceous rift system is mainly preserved. Due to low overall convergence and absence of oceanic subduction, this orogen preserves one of the best geological records of early orogenesis, the transition from early convergence to main collision and the transition from collision to post-convergence. During these transitional periods major changes in orogen behavior reflect evolving lithospheric processes and tectonic drivers. Contributions by the OROGEN project have shed new light on these critical periods, on the evolution of the orogen as a whole, and in particular on the early convergence stage. By integrating results of OROGEN with those of other recent collaborative projects in the Pyrenean domain (e.g., PYRAMID, PYROPE, RGF-Pyrénées), this paper offers a synthesis of current knowledge and debate on the evolution of this immature orogen as recorded in the synorogenic basins and fold and thrust belts of both the upper European and lower Iberian plates. Expanding insight on the role of salt tectonics at local to regional scales is summarised and discussed. Uncertainties involved in data compilation across a whole orogen using different datasets are discussed, for example for deriving shortening values and distribution.
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Abu Sharib, A. S. A. A., and T. H. Bell. "Radical changes in bulk shortening directions during orogenesis: Significance for progressive development of regional folds and thrusts." Precambrian Research 188, no. 1-4 (July 2011): 1–20. http://dx.doi.org/10.1016/j.precamres.2011.03.008.
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Battaglia, S., F. Gherardi, G. Gianelli, L. Leoni, and F. Origlia. "Clay mineral reactions in an active geothermal area (Mt. Amiata, southern Tuscany, Italy)." Clay Minerals 42, no. 3 (September 2007): 353–72. http://dx.doi.org/10.1180/claymin.2007.042.3.08.
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AbstractThis study characterizes the effects of fluid migration into a predominantly shale cover which seals the active geothermal system of Mt. Amiata (Tuscany, Italy). During Alpine orogenesis the shale unit was affected by regional metamorphism at the limit of the diagenesis-anchizone. Subsequently, the phyllosilicate clay minerals of the shales underwent significant alteration at diagenetic temperatures (175±25ºC as determined by the geochemical model) by the pervasive circulation of fluids activated by the geothermal field. The overall mineralogical assemblages indicate that the main transformations consisted mostly of destabilization of illite and formation of kaolinite together with large amounts of I-S mixed layers, with higher smectite content and decreased Reichweite I-S ordering (from R3 to R1) with respect to the original, unaltered phases. Application of computer modelling indicates that the circulation of CO2-rich geothermal fluids into the shale unit was responsible for the observed phyllosilicate clay mineral transformations.
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Stephens, Michael B., Ulf Bergström, and Carl-Henric Wahlgren. "Chapter 14 Regional context and lithotectonic framework of the 1.1–0.9 Ga Sveconorwegian orogen, southwestern Sweden." Geological Society, London, Memoirs 50, no. 1 (2020): 337–49. http://dx.doi.org/10.1144/m50-2018-17.
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AbstractThe 1.1–0.9 Ga Sveconorwegian orogen in southwestern Scandinavia belongs to the global system of mountain belts established during the assembly of the supercontinent Rodinia. An overall north–south structural trend and five lithotectonic units bounded by crustal-scale shear zones characterize this orogen. In Sweden, the Eastern Segment abuts the orogen's cratonic foreland eastwards and is separated from the Idefjorden terrane westwards by a ductile shear zone, up to 5 km thick, displaying a sinistral transpressive component. These two lithotectonic units differ on the basis of their pre-Sveconorwegian accretionary tectonic evolution, and the timing of Sveconorwegian high-pressure metamorphism, anatexis and polyphase deformation. High-pressure granulites and migmatites formed at c. 1.05–1.02 Ga in the Idefjorden terrane; eclogites, high-pressure granulites and migmatites at c. 0.99–0.95 Ga in the Eastern Segment. Magmatic activity and crustal extension progressed westwards at c. 0.98–0.92 Ga. Prior to or at 0.93–0.91 Ga, greenschist facies shear deformation with top-to-the-foreland movement affected the frontal part of the orogen. Geodynamic uncertainties concern the affinity of the Idefjorden terrane relative to Fennoscandia (Baltica), the character of the Sveconorwegian orogenesis, and the contiguous or non-contiguous nature of the erosional fronts of the late Mesoproterozoic–early Neoproterozoic orogens in Sweden and Canada.
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Liu, Xue Long, Wen Chang Li, Yan Yang, and Guang Hou Yin. "Tectonic Environment and Geochemical Characteristics of Geza Arc Magmatic Rocks in Sanjiang Orgenic Belt, SW China." Advanced Materials Research 734-737 (August 2013): 444–47. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.444.
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Geza island arc located in the southwest Sanjiang tectonic igneous rock belts, it was a products of Ganzi-Litang oceanic crust diving to Zhongdian Landmasses in late Triassic and a important of newly discovered copper polymetallic belts in the recent years in China. The regional strong tectonic-magmatic activity throughout the island-arc orogenesis from beginning to the end, the rich mineralization developed in the different times and different circumstances. Based on the development stage of island arc orogenic,the distribution of intrusive rocks, rocks composition, geochemical characteristics, Geza island arc granit belt can be divided into three belts. Lithogeochemical characteristics show that the porphyry (porphyrite) and island-arc granite rocks have the same rock series (high-K calc-alkaline) and the same genetic type (I-type granite); these rocks trace elements very similar to granite of island arc, which enriched in Ba, La, Hf, Au,chalcophile elements Cu,Pb, siderophile elements Mo, Ni, and depleted in Rb, Nb, P, Ti.
Dissertations / Theses on the topic "Regional orogenesis"
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Clark, J. M. "Defining the style of mineralisation at the Cairn Hill magnetite-sulphide deposit; Mount Woods Inlier, Gawler Craton, South Australia." Thesis, 2014. http://hdl.handle.net/2440/109968.
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This item is only available electronically.The Cairn Hill Fe-(Cu-Au) deposit is located within the World-class 1.6 Ga Olympic iron oxide-copper-gold (IOCG) Province of the Gawler Craton, South Australia. Cairn Hill deposit formation was penecontemperaneous with regional orogenesis, and is interpreted as a deep-level, ‘magnetite-rich’ end-member IOCG system hosted by an upper-amphibolite quartzofeldspathic ortho-gneiss and Mesoproterozoic (1600 – 1575 Ma) Hiltaba-equivalent Balta-suite granites and granodiorites. U-Pb zircon SHRIMP dating of a representative host rock and cross-cutting foliated granitic dyke, constrains the timing of mineralisation between ~1587 Ma and ~1525 Ma, respectively; suggesting an affinity to Hiltaba-age granitoids. The deposit strikes E-W over a distance of 1.3 km and is up to 40 m wide. It is characterized by two mineralised zones: the North- and South- Lodes, coincident with subsidiary structures within the transpressional Cairn Hill Shear Zone (CHSZ), and concordant with the strike of the encompassing magnetic anomaly. Progressive exhumation resulted in temperature and pressure decreases under high-fluid pressure causing the CHSZ to cross the brittle-ductile transition. This occurred relatively late in the hydrothermal-metamorphic evolution, resulting in a contractional duplex in a restraining bend suggestive of a positive flower structure providing an optimal conduit for hydrothermal fluid-flow. Early Na-Ca alteration has affected the host rocks predominantly characterised by albite + scapolite + diopside ± actinolite/titanite. Extensive K-Fe metasomatism has affected the host rocks overprinted by localised zones of intense, texturally-destructive high-temperature magnetite-biotite alteration that is typical of a transitional-style IOCG system. Associated hypogene iron mineralisation predominantly consists of magnetite, with extensive zones of a superimposed texturally-complex sulphide assemblage (pyrite-pyrrhotite-chalcopyrite). Definition of the IOCG deposit clan remains a contentious issue, primarily due to mis-classification and poor understanding of some individual deposits. Nevertheless, the general consensus is that IOCG deposits sensu-stricto represent a spectrum between high-temperature, deeper magnetite-rich end-member systems, such as Cairn Hill, and lower-temperature, shallower hematite-rich end-members.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2014
Book chapters on the topic "Regional orogenesis"
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Jones, James V., and Christopher G. Daniel. "Circa 1.50–1.45 Ga metasedimentary rocks in southwestern Laurentia provide distinctive records of Mesoproterozoic regional orogenesis and craton interactions." In Laurentia: Turning Points in the Evolution of a Continent. Geological Society of America, 2022. http://dx.doi.org/10.1130/2022.1220(09).
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ABSTRACT The discovery of multiple deformed and metamorphosed sedimentary successions in southwestern Laurentia that have depositional ages between ca. 1.50 and 1.45 Ga marked a turning point in our understanding of the Mesoproterozoic tectonic evolution of the continent and its interactions with formerly adjacent cratons. Detrital zircon U-Pb ages from metasedimentary strata and igneous U-Pb zircon ages from interbedded metavolcanic rocks in Arizona and New Mexico provide unequivocal evidence for ca. 1.50–1.45 Ga deposition and burial, followed by ca. 1.45 and younger deformation, metamorphism, and plutonism. These events reflect regional shortening and crustal thickening that are most consistent with convergent to collisional orogenesis—the Mesoproterozoic Picuris orogeny—in southwestern Laurentia. Similar metasedimentary successions documented in the midcontinent of the United States and in eastern Canada help to establish ca. 1.45 Ga orogenesis as a continent-scale phenomenon associated with a complex and evolving convergent margin along southern Laurentia. Metasedimentary successions of similar age are also exposed across ~5000 km of the western Laurentian margin and contain distinctive 1.6–1.5 Ga detrital zircon populations that are globally rare except in select cratonic provinces in Australia and Antarctica. The recognition of these distinctive detrital zircon ages provides a transient record of plate interactions prior to breakup of Nuna or Columbia ca. 1.45 Ga and provides key constraints on global plate reconstructions.
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Chapman*, Alan D., Doug Yule, William Schmidt, and Todd LaMaskin. "Middle Jurassic to Early Cretaceous tectonic evolution of the western Klamath Mountains and outboard Franciscan assemblages, northern California–southern Oregon, USA." In From Terranes to Terrains: Geologic Field Guides on the Construction and Destruction of the Pacific Northwest, 73–130. Geological Society of America, 2021. http://dx.doi.org/10.1130/2021.0062(04).
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ABSTRACT The Klamath Mountains province and adjacent Franciscan subduction complex (northern California–southern Oregon) together contain a world-class archive of subduction-related growth and stabilization of continental lithosphere. These key elements of the North American Cordillera expanded significantly from Middle Jurassic to Early Cretaceous time, apparently by a combination of tectonic accretion and continental arc– plus rift-related magmatic additions. The purpose of this field trip is twofold: to showcase the rock record of continental growth in this region and to discuss unresolved regional geologic problems. The latter include: (1) the extent to which Mesozoic orogenesis (e.g., Siskiyou and Nevadan events plus the onset of Franciscan accretion) was driven by collision of continental or oceanic fragments versus changes in plate motion, (2) whether growth involved “accordion tectonics” whereby marginal basins (and associated fringing arcs) repeatedly opened and closed or was driven by the accretion of significant volumes of material exotic to North America, and (3) the origin of the Condrey Mountain schist, a composite low-grade unit occupying an enigmatic structural window in the central Klamaths—at odds with the east-dipping thrust sheet regional structural “rule.” Respectively, we assert that (1) if collision drove orogenesis, the requisite exotic materials are missing (we cannot rule out the possibility that such materials were removed via subduction and/or strike slip faulting); (2) opening and closure of the Josephine ophiolite-floored and Galice Formation–filled basin demonstrably occurred adjacent to North America; and (3) the inner Condrey Mountain schist domain is equivalent to the oldest clastic Franciscan subunit (the South Fork Mountain schist) and therefore represents trench assemblages underplated >100 km inboard of the subduction margin, presumably during a previously unrecognized phase of shallow-angle subduction. In aggregate, these relations suggest that the Klamath Mountains and adjacent Franciscan complex represent telescoped arc and forearc upper plate domains of a dynamic Mesozoic subduction zone, wherein the downgoing oceanic plate took a variety of trajectories into the mantle. We speculate that the downgoing plate contained alternating tracts of smooth and dense versus rough and buoyant lithosphere—the former gliding into the mantle (facilitating slab rollback and upper plate extension) and the latter enhancing basal traction (driving upper plate compression and slab-shallowing). Modern snapshots of similarly complex convergent settings are abundant in the western Pacific Ocean, with subduction of the Australian plate beneath New Guinea and adjacent island groups providing perhaps the best analog.
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Anderson, Thomas H. "Plate convergence, consumption, collision, coupling, capture, and formation of mantle waves—Linkages to global orogenesis and epeirogeny." In In the Footsteps of Warren B. Hamilton: New Ideas in Earth Science. Geological Society of America, 2022. http://dx.doi.org/10.1130/2021.2553(13).
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ABSTRACT Widespread episodes of major contractional orogenesis correlate commonly with ages of high-pressure eclogitic rocks formed during bottom-driven, induced subduction of crustal terranes. Rapid exhumation of the deeply emplaced crust has led to the development of the concept of a “tectonic dunk.” The dunk process is a hallmark component of a suite of linked tectonic, magmatic, metamorphic, and sedimentologic processes that systematically follow plate interactions, including collision, coupling, and capture resulting in plate reconfiguration and changes of movement. Plate capture, which takes place during mechanical connection of plates within a “clutch” zone, is followed generally by an abrupt transition to plate stretching in response to drag or plate spin. Plate stretch, which is accommodated during drag by a network of complementary strike-slip and normal faults or during spin by regional domains of transtension, is recorded by “postorogenic,” back-arc extension, basin formation, and magmatism, extensive domains of which comprise large igneous provinces. As a captured continental plate is dragged or rotates, ductile mantle is disrupted and displaced by protuberances, such as a slab coupled against the base of an overriding plate and/or orogenic roots extending down from a cratonic core. The mantle turbulence resembles a wave-like ship’s wake with tsunami-like movement, albeit below crust. The arrival of a moving mantle bulge or wave is inferred to be focused along continental plate margins where subduction is induced, as recorded by magmatism and eclogitic rocks that form during deep emplacement of crustal terranes. Concurrent shortening of crust in the vicinity of the plate margin is inferred from inversion and uplift of marginal rift basins, obduction, and development of fold-and-thrust belts. As the mantle wave passes beneath plate interiors, tens to hundreds of meters of uplift, recorded by oceanic atolls, continental stream incision, regional unconformities, and local transitions to evaporite within shelf settings, record epeirogeny. After passage of the wave, common development of sheet-like bodies of quartzose sandstone, especially during the early Paleozoic, suggest postwave, regional subsidence. Resumption and re-invigoration of extension are recorded by eduction of dunked crust and conspicuous, widespread, volcanic eruptions recorded by tuffaceous layers intercalated with carbonaceous black shale within broad basins developed above thickened crust.
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Oliver, Nicholas H. S., Brian Thomson, Flavio H. Freitas-Silva, and Rodney J. Holcombe. "Chapter 5: The Low-Grade, Neoproterozoic, Vein-Style, Carbonaceous Phyllite-Hosted Paracatu Gold Deposit, Minas Gerais, Brazil." In Geology of the World’s Major Gold Deposits and Provinces, 101–20. Society of Economic Geologists, 2020. http://dx.doi.org/10.5382/sp.23.05.
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Abstract The Paracatu deposit in Brazil is a shallowly dipping, bulk-tonnage, low-grade, vein-style orogenic Au orebody hosted in very strongly deformed Neoproterozoic carbonaceous phyllite of the southern Brasília fold belt. At regional to district scales, the gold orebody lies along the eastern, hanging-wall edge of a major thrust of the ~630 Ma Brasiliano orogeny. This thrust cuts through a facies transition between clastic-dominated rocks of the Canastra Group and carbonate-dominant rocks of the Vazante Group, deposited at ~1000 Ma in a rift to passive-margin environment on the flank of the São Francisco craton. At the same scales, the footwall of this major thrust system hosts numerous structurally controlled zinc deposits including Vazante and Morro Agudo. At Paracatu, ore genesis occurred primarily by the formation of early tectonic quartz sulfide-carbonate veins, prior to substantial ductile deformation (boudinage), local physico-chemical reworking of these veins, and redistribution of some gold. Structural, geochemical, and isotopic data indicate a strong influence of the local rocks (cm to 100-m scales) on many ore ingredients, and the quartz and carbonate in ore veins were most likely derived locally (cm to m scales). However, the coassociation of gold and arsenic with the boudinaged veins and a major thrust, and the absence of metal enrichments normally associated with syngenetic metalliferous black shales, supports a model of far-field derivation of gold within this metasedimentary package (km to 10-km scales). Transport of metal-bearing fluids toward a favorable structural and chemical site during thrusting and orogenesis was possibly focused, during precipitation to ore grades, by the position of transverse structures in the basement, which also influenced deposition of the adjacent zinc deposits. Successful mining of the low-grade resource was initially favored by the subhorizontal orebody geometry and weathering characteristics, and subsequently by high production rates from the 100-m-thick mineralized zone.
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Roberts, Neil, and Jane Reed. "Lakes, Wetlands, and Holocene Environmental Change." In The Physical Geography of the Mediterranean. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780199268030.003.0021.
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The Mediterranean regions of the world are defined on the basis of their climate, with a distinct hot, dry summer season and a warm, wet winter (Grove and Rackham 2001; Chapter 3). Spring and autumn seasons are less well defined but often contribute significantly to annual precipitation. Strictly defined in this way, the Mediterranean region is confined to parts of Italy, Greece, southern France, the south and east of Spain (non-Atlantic climate), the Maghreb and Cyrenaica in North Africa, and narrow coastal strips running through the Balkans, southern and western Turkey, and the Levant (Syria, Lebanon, and Israel-Palestine). Outside these areas, climate becomes humid temperate (western Europe, Black Sea), arid (Sahara, northern Arabia), or continental (interior areas of the Balkans, Turkey and Iberia, the Zagros mountains of Iran/Iraq). Even within the strict definition are found subalpine mountain zones, so it is a difficult study region to demarcate absolutely. In a similar vein to the volume by Zolitschka et al. (2000), this chapter extends the scope to important wetlands in some neighbouring regions, and deals effectively with the circum-Mediterranean. Thus, we include lakes Ohrid and Dojran in the Balkans, wetlands of the continental interior of Turkey, north-western Iran and the Caucasus (e.g. Lakes Van, Urmia, and Sevan), the climatically dry Jordan rift valley which includes the Dead Sea, and the subalpine northern Italian lakes such as Como and Maggiore. The Mediterranean basin is geologically complex and has its origin in the progressive closure of the Sea of Tethys during the Tertiary (Laubscher and Bernoulli 1977). Plate convergence between Africa and Eurasia led to a major phase of orogenesis and the creation of fold mountains including the Atlas, Sierra Nevada, Alps, Apennines, and Taurus, and to plateau uplift in Iberia and Anatolia (Chapter 1). These mountain ranges are commonly dominated by massively deformed Mesozoic limestones that now form karst landscapes (e.g. Dinaric Alps; Ager 1980; Chapter 10). Tectonic movement also led to extensive late Cenozoic volcanism, notably in southern and central Italy, the Hellenic arc, Anatolia, and around the Jordan rift (Chapter 15).
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Mewa, Getnet, and Filagot Mengistu. "Assessment of Landslide Risk in Ethiopia: Distributions, Causes, and Impacts." In Landslides [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.101023.
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The complex geological and geomorphological settings of Ethiopia, consisted of highland plateaus, escarpments, deeply dissected valleys, and flat lowlands, are results of multiple episodes of orogenesis, peneplanation, crustal up-doming, faulting, and emplacement of huge volumes of lava. The broad elevation contrast raging from about −125 m to 4550 m Above Mean Sea Level (AMSL) is an important factor in determining the climate regimes, vegetation types, and even populations’ lifestyles. In Ethiopia landslides, mostly manifested as rockfall, earth slide, debris, and mudflow, are among the major geohazard problems that immensely affects life, infrastructures, and the natural environment. They widely occur in the central, S-SW, and N-NW highland regions. This study discusses the distributions, causes, and impacts of landslides and presents a susceptibility zoning map produced applying the weighted overlay analysis method in the ArcGIS environment. For this purpose, key parameters (lithology, elevation, rainfall, slope angel, land use-land cover, and aspect) were selected and assigned weights by considering their contributions to slope failures. Correlations with inventory data have shown very good matching, where more than 90% of the observed data fall in areas categorized either as moderate, high, or very high susceptible zones, where appropriate risk assessments could be mandatory before approval of major projects.
Conference papers on the topic "Regional orogenesis"
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Economos, Rita C., Brody P. Friesenhahn, Andrew P. Barth, Joseph L. Wooden, Robert E. Powell, Scott R. Paterson, J. Lawford Anderson, and Adam J. Ianno. "CHARACTER OF LATE CRETACEOUS MAGMATISM SPANNING THE TRANSITION FROM SUBDUCTION TO LARAMIDE OROGENESIS IN THE WESTERN/CENTRAL MOJAVE REGION." In 116th Annual GSA Cordilleran Section Meeting - 2020. Geological Society of America, 2020. http://dx.doi.org/10.1130/abs/2020cd-347400.
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