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Subduction and obduction. 9% in cases as compared to cases reported in 2020.
KEKELIA5, S. Apr 28, 2011 · The annual subduction/obduction rate can be calculated in Lagrangian and Eulerian coordinates. When the overriding plate is oceanic, dense forearc oceanic lithosphere might be obducted onto light continental crust forming an ophiolite (Tethyan‐style ophiolite obduction). X. Based on our field work, new stratigraphical, petrological, geochemical and geochronological data combined with previous data we present new insights on the Jun 25, 2015 · Continental subduction takes place in the final stage of subduction when all oceanic lithosphere is consumed and continental passive margin is pulled into the mantle. , 2004; Agard et al. L. (A) The palinspastically restored cross section across Sep 6, 2022 · A subduction zone is a collision between two of Earth's tectonic plates, where one plate sinks into the mantle underneath the other plate. Pelletier, B. However, shallow subduction is neither necessary nor sufficient to uniquely explain the inboard advance of deformation within continental plate interiors. Oct 8, 2019 · "Timing of subduction initiation, arc formation, ophiolite obduction and India–Asia collision in the Himalaya", Himalayan Tectonics: A Modern Synthesis, P. The Zagros orogen and the Iranian plateau preserve a record of the long-standing convergence history between Eurasia and Arabia across the Neo-Tethys, from subduction/obduction processes to present-day collision (from ~ 150 to 0 Ma). Jun 16, 2020 · The attempted subduction of the Norfolk Ridge eventually led to the end-Eocene obduction. Jun 1, 2011 · The subduction/obduction rate for the cases including mixed layer depth perturbations induced by tropical cyclones at a given station is discussed in Section 3. MELKONYAN4, S. MÜLLER2, T. May 19, 2023 · This contribution shows how the two types of oceanic fragments, blueschists and eclogites, on one hand, and ophiolites on the other, preserve crucial information on the dynamics of oceanic convergence, that is, subduction and obduction. Subduction is a fraction of the detrained mass flux: it refers to that part of the detrained water mass that is not entrained in the next winter (Cushman-Roisin 1987). The Great Smokies, Mt. When the overriding plate is oceanic, dense forearc oceanic lithosphere might be obducted onto light continental crust forming an ophiolite (Tethyan-style ophiolite obduction). subductions are clearly identified, one related to the Neotethys subduction beneath the Eurasian. 85–80 Ma (Fig. The opposite process is sometimes referred to as obduction. Feb 17, 2022 · Subduction/obduction rate in the North Pacific diagnosed by an eddy-resolving model. Google Scholar Sep 5, 2023 · The Timor ophiolites, part of the young Banda arc-forearc, experienced only a short magmatic history between 8 and 10 million years ago before being rapidly emplaced onto the Australian margin Oct 1, 2005 · Subduction is a fraction of the detrained mass flux: it refers to that part of the detrained water mass that is not entrained in the next winter (Cushman-Roisin 1987). , 2022), which indicates that the entire obduction crisis of the Semail ophiolite from subduction Apr 1, 2020 · Subduction/obduction are crucially important processes for the climate and ecological cycle in the ocean. Feb 14, 2022 · All the typical structures of active convergence in Semail ceased by 75-70 Ma (Agard et al. , 1985; Michard et aI. AVAGYAN4, G. Oct 30, 1998 · Subduction–obduction processesSubduction and obduction processes affecting the oceanic sequences of the Piémont ocean are shown in Fig. (2017). Where one tectonic plate converges with a second plate, the heavier plate dives beneath the other and sinks into the mantle. Searle Download citation file: Obduction can occur where a fragment of continental crust is caught in a subduction zone with resulting overthrusting of oceanic mafic and ultramafic rocks from the mantle onto the continental crust. The annual subduction rate averaged from 2001 to 2004 is estimated at 49. , Wang, F. From its onset, however, subduction has progressively consumed most of the Nov 21, 2023 · The word subduction might not be familiar to most people, but it is an essential process in geology. Water mass formation/ erosion can also take place in relatively narrow regions Jan 1, 1991 · The Oman obduction can be considered as the type-obduction. Convergent boundary movement is divided into two types, subduction and collision, depending on the density of the involved plates. The physics involved in subduction and obduction, however, are completely different. Water mass formation/ erosion can also take place in relatively narrow regions Feb 29, 2020 · The timings of formation and emplacement/obduction of this ophiolite had remained tentative. We May 31, 2018 · For the effective trajectory, subduction (obduction) is calculated according to equation 1 (2). In previous studies such calculations primarily focused on the case with the seasonal cycle only. It involved two main stages of thrusting of oceanic lithosphere: 1) onto the adjacent oceanic crust and lower continental margin Aug 1, 2013 · According to Aurelio et al. subduction/obduction rate can shed light on water mass formation/erosionasseen fromthebaseofthemixed layer. 1. Why Does Subduction Happen? A new three-dimensional method is proposed for calculating the annual mean subduction and obduction rate in the ocean and applied to the North Pacific Ocean. F. Treloar, M. Google Scholar Liu, L. Subduction takes place mainly in the subtropical basin where Jul 1, 2018 · Based on the characteristics of oceanic circulation in a monsoon-dominated ocean, a new framework of annual ventilation, including subduction and obduction, is postulated and applied to the North Indian Ocean based on both SODA and GODAS. The Oman obduction is probably the best obduction example available, Sep 14, 2010 · insights on the subduction, obduction and collision processes recorded in the Lesser Caucasus. Google Scholar Liu Qinyu, Hu Haibo, Liu Hailong, et al. May 1, 2014 · There have been several studies investigating obduction processes during subduction initiation [Leroy et al. It involved two main stages of thrusting of oceanic lithosphere: i) onto the adjacent oceanic crust and lower continental margin, without emergence; ii) onto the upper continental margin, with emergence of Dec 18, 2015 · Since the Mesozoic, Africa has been under extension with shorter periods of compression associated with obduction of ophiolites on its northern margin. Nittany near Penn State's University Park campus, and all of the subduction/obduction rate can shed light on water mass formation/erosionasseen fromthebaseofthemixed layer. Apr 1, 2024 · It can be noted that the formation and obduction ages of these ophiolites fall in a narrow window of 135 Ma to 65 Ma, and coincide with the three major mantle plume events along the Indian subcontinent margin [viz. Feb 23, 2023 · Abstract A new three-dimensional method is proposed for calculating the annual mean subduction and obduction rate in the ocean and applied to the North Pacific Ocean. Jan 1, 2011 · 1 Introduction. 3). The physics involved in subduc-tion and obduction, however, are completely different. GALOYAN4 & J. Here, we present results of our effort to date these events by 147 Sm– 143 Nd and 40 Ar– 39 Ar methods and understand their implications for the evolution of the Andaman subduction zone. (2012), the archipelago is the outcome of a complex series of geological events that involved continental rifting, oceanic spreading, subduction, ophiolite obduction OBDUCTION VERSUS SUBDUCTION AND COLLISION PRESENT Alps 449 Rifq-B. 1), where shortening has been active throughout Feb 1, 2022 · Ophiolites are remnants of the oceanic crust and lithospheric mantle that have been accreted to the continental crust during tectonic events such as subduction and obduction (Dewey and Bird, 1971; Dewey, 1976; Coleman, 1977; Nicolas, 2000; Nicolas and Boudier, 2003; Dilek, 2003; Dilek and Robinson, 2003; Furnes and Dilek, 2022), and can be Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Obduction driving forces and dynamics also need to be better understood from both natural observations and numerical modeling perspectives. Jul 31, 2024 · Plate tectonics - Continental Drift, Subduction, Earthquakes: The extent to which plate tectonics has influenced Earth’s evolution through geologic time depends on when the process started. , 2005; Oncken et al. (2015) also lack slab detachment, and show periods of continental subduction that generally last longer The Oman obduction can be considered as the type-obduction. Subduction zone, oceanic trench area marginal to a continent in which, according to the theory of plate tectonics, older and denser seafloor underthrusts the continental mass, dragging downward into the Earth’s upper mantle the accumulated trench sediments. Dewey, J. May 1, 2014 · Obduction ensuing from subduction initiation is successfully reproduced in a number of models (15 out of 26) over timescales of a few Myrs, as continental lithosphere gets underthrust beneath oceanic lithosphere (Fig. 2006. Updated sea-floor kinematics associated with a comprehensive review of geologic, geochemical, and geophysical data provide new constraints on the geodynamics of this puzzling area. Such systems may feature back-arc extension and ophiolite obduction postdating initial collision. 2012. HP–LT metamorphism record a long-lasting history of oceanic Although the exhumation of high pressure (HP) and ultrahigh pressure (UHP) rocks is an integral process in subduction, it is a transient process, likely taking place during the perturbation in subduction zones. The closure of the Neo-Tethys Ocean, by the Upper Cretaceous, is characterized by a major obduction event, from the Mediterranean region to Jun 14, 2024 · Although some researchers also defined the inception of subduction and consequent development of a metamorphic sole beneath an ophiolite as obduction (emplacement), or at least first stage of Nov 27, 2022 · The first type occurs when ocean lithosphere is subducted below other ocean 1ithosphere (“intra-oceanic subduction zone”) to create a volcanic Island arc system built on oceanic crust (“ensimatic island arc”; sima—artifical word first used by Wegener made from silicon and magnesium to characterize ocean floor and Earth’s mantle). 1 Sv. The end of obduction and the decrease of convergence velocities (Fig. , and Huang, R. , 2015; Horton, 2018a) (Fig. g. Two parallel mountain ranges commonly develop above such a subduction zone – a coastal range consisting of sedimentary strata and hard rock lifted out of the sea (accretionary wedge), and a volcanic range farther inland (volcanic Jun 1, 2021 · Although the basal ophiolite obduction thrust complex and the Fleur-de-Lys-basement subduction-eduction surfaces must have been initially gently-dipping to sub-horizontal, they were folded and broken by thrusts during late Taconian, late Ordovician Salinic-Mayoian, and Acadian shortening. This new method can provide the three-dimensional feature of subduction Introduction. When a portion of the continental crust is driven down into the subduction zone, due to its buoyancy it returns to the surface relatively quickly. In order to better understand what controls subduction initiation and, in turn, obduction, the amount of obduction (% O = % w f. Further analysis indicates that the high-frequency components of the eddy field, especially those with timescale shorter than 10 days, are the most critical factor enhancing subduction/obduction. The PCB May 1, 2023 · Both types reflect the mechanical behavior and “hiccups” of the subduction plate boundary, during subduction initiation and mature subduction, respectively. 7 Sv. (1994). Focal mechanism solutions of several compressional type earthquakes with magnitudes of M = 6. Jul 30, 2021 · Subduction initiation (SI) holds a key to the inception of plate tectonics and the evolution of the solid Earth 1,2,3,4,5,6. 1 Hlmalaya Vardar. Continental lithosphere is of lower density and Mar 1, 1976 · Obduction from rear-arc basins It has been suggested (Dewey and Bird, 1971) that a common form of ophiolite obduction is related to the closure of rear-arc marginal basins and that, during such closure by subduction, slices of oceanic crust and mantle may be expelled onto adjacent continental forelands and emplaced as ophiolite sheets. 0 < σ θ < 27. Due to the beta spiral, the subducted/obducted water at a given station can spread over/come from a wide range with different densities in the subsurface ocean. This is a matter of ongoing debate among geologists. Nov 1, 2001 · The Spong arc is interpreted to have formed above a northward-dipping subduction zone that was responsible for the obduction of the Spontang ophiolite during the Late Cretaceous–Early Paleocene. , 2020, Beck et al. This paper presents a synthetic view of the geodynamic evolution of the Zagros orogen within the frame of the Arabia–Eurasia collision. The annual subduction/obduction rates vary greatly on the Feb 15, 2012 · Abstract Ventilation, including subduction and obduction, for the global oceans was examined using Simple Ocean Data Assimilation (SODA) outputs. 2 Sv/6. Discover the world's research 25 Jan 1, 2011 · Subduction, obduction. 1 Subduction and its Variability in the North Indian Ocean Aug 27, 2018 · Subduction zones are unique to Earth and fundamental in its evolution, yet we still know little about the causes and mechanisms of their initiation. 8 Sv, whereas the annual obduction rate is 26. Oct 1, 1995 · Abstract Ventilation in the North Atlantic and North Pacific is examined by analyzing the Levitus climatological data and the Hellerman and Rosenstein wind stress data. , 1996, Chan et al. The opposite process is sometimes re-ferred to as obduction. Obduction is a term applied to the transport of oceanic crust and mantle across continental margins (Coleman, 1971). Reconstruction of continents in paleomagnetic reference frame of Torsvik et al. The best-known and largest-scale example is the South American subduction zone with the Andes mountain belt (Isacks, 1988; McQuarrie et al. 2 b) mark the end of BS exhumation in the NSZ (Fig. 5–10 Ma) chokes subduction processes in the OSZ and BS and eclogites are rapidly exhumed. Compare and contrast subduction and obduction; Identify the causes of tsunamis; Describe the geometry of tsunami waves in the deep ocean versus the shallow marine environment; Explain why the location of the Rocky Mountains is an anomaly, and how this likely occurred. As a result, large areas of the Anatolide-Tauride Block subsided and became a region of pelagic carbonate sedimentation during the Campanian. , 2006; Armijo et al. Chinese Journal of Oceanology and Limnology, 34(4): 835–846. (1983). 2 Sv/11 Sv averaged from 1960 to 2009, with 4. May 27, 2022 · The correlation of flat slab subduction and ridge subduction with intraplate basement uplift demonstrates a link between subduction geometry and retroarc shortening. This is a section of Apr 23, 2018 · C'est une vidéo qui concerne La subduction et l'obduction et la collision en détail :) N'oubliez pas de vous abonnez a ma chaine youtube pour avoir chaque jo Dec 1, 2001 · The subduction of oceanic lithosphere at present-day plate margins and concomitant arc magmatism are important indicators of the dynamic evolution of the earth’s surface due to plate tectonics. Finally, we conclude in Section 5. 9% in cases as compared to cases reported in 2020. This figure together with Fig. The failed plateau subduction only generates a minor amount of mass loss, as corresponds to an elevated gravity anomaly. By extending these calculations to the case including the diurnal cycle of the mixed layer depth, the annual subduction/obduction rate can be greatly increased. The rates of convergence Jan 18, 2022 · Subduction zone earthquakes and their cascading consequences result in some of the most devastating natural hazards on Earth. ADAMIA6, V. May 31, 2018 · The annual subduction/obduction rates vary greatly on the interannual and decadal time scales. Modern examples include the Alboran and Banda arcs. Jun 1, 2024 · At the other end of the spectrum of overriding plate deformation are those subduction zones that experience overriding plate shortening. Article Google Scholar Liu L L, Huang R X, Wang F. The mantle plume impingements caused plate tilting and triggered the subduction/obduction that is well preserved by sharp inflexions in MMA and the spreading rates. Some of the other Jan 1, 2011 · Subduction, obduction. In nature, other processes can affect the dynamics of a subduction/obduction system such as neighboring subduction zones, global mantle flow, mid-ocean ridges, or mantle plumes. May 16, 2001 · Ophiolite obduction over the passive margin of the Anatolide-Tauride Block started in the Santonian soon after the inception of subduction in the Turonian. P. 8 Sv (1 Sv = 10(6) m(3) s(-1)), while the corresponding global obduction rate is estimated at 482. MOSAR9 1 Université de Nice Sophia Antipolis, CNRS, OCA-UMR Géosciences Azur Obduction zones occurs when the continental plate is pushed under the oceanic plate, but this is unusual as the relative densities of the tectonic plates favours subduction of the oceanic plate. , 1999, Burg and Podladchikov, 2000), and gravitational (Raleigh–Taylor (RT)) instabilities in thickened, negatively buoyant lithosphere (e. Dec 1, 2022 · In practice, active obduction of the overriding plate leads to shallow subduction of the plateau front (Figures 2a and 2b), which is significantly weakened after subduction with an opposite polarity (Figures 2c and 2d). , 2015; Advokaat et al. Old, cold sea floor goes down subduction zones beneath warmer sea floor or continent, but what happens when a high-floating continent or island arc tries to go down a trench under another continent or island arc? The answer is obduction, a BIG collision. May 19, 2023 · Their mutual relationships, as well as the similarities and differences in the mechanisms leading to their preservation, allow tracking the evolution of the subduction process through time, from the onset of intraoceanic subduction to the cessation of continental subduction, and, in some cases, to the obduction of ophiolites. The subduction zone, accordingly, is the Jan 1, 1995 · Subduction and obduction in the ocean are very complicated processes involving the seasonal cycle. 1): pure-shear thickening; simple shear subduction or underplating; folding (Cloetingh et al. , 2014] and during terminal stage subduction [Chemenda et al. A later phase of higher-level shearing deformation with SW (continentward) vergence, during the Campanian, accompanied the thrusting of the Hawasina Nappes and the obduction of the Semail In very rare cases, part of a continental plate may become trapped beneath a descending oceanic plate in a process called obduction . 9 to 7. In the case where a continental plate is forced under an oceanic plate, this is called obduction. Feb 8, 2012 · Ventilation, including subduction and obduction, for the global oceans was examined using Simple Ocean Data Assimilation (SODA) outputs. g Mar 1, 2014 · In continents, subduction is only one of the four possible mechanisms of accommodation of tectonic shortening (Fig. Subduction of the Arabian continental crust beneath the obducting Semail ophiolite to ~78–90 km depth has been proven by ther- Keywords: Intra-Pontide suture, Ä°stanbul Zone, Sakarya Zone, U-Pb zircon ages, Rb-Sr mica ages We provide new isotopic data from the Intra-Pontide Suture Zone, which indicate Early Cretaceous collision between the Sakarya and Ä°stanbul terranes following the consumption of the Intra-Pontide Ocean. Long-term changes of subduction and obduction over the global ocean and their mechanisms in the 20th century (in Chinese) [dissertation]. 2. and Stephan, J. The annual subduction/obduction rate enhancement induced by tropical cyclones in the North Pacific is estimated in Section 4. 1994; Coleman & Wang 1995; Ernst & Liou 1999; Chopin 2003), or subducted and recycled in the mantle (e. Considering the horizontal resolution, SODA results are mainly discussed interval between ophiolite obduction, the end of subduction, and potentialslabdrop-o˙isuncertain,weestimateittobe˘5 10Myr. The global subduction rate is estimated to have increased 7. SI is also an important factor that impacts the motion and the Jan 31, 2001 · ridge subduction or directly to obduction: obduction onto passive margin (Tethyan) or accretionary uplift (Cordilleran) Volcanic rocks: primitive arc tholeiites (basalt to basaltic-andesite) high-Mg andesites, boninites, tholeiitic ankaramites: andesite, dacite, basaltic andesite: MORB-like or OIB: none: Plutonic rocks: layered gabbro Oct 23, 2013 · compared the simulated subduction rate of upper Southern Ocean waters against the one obtained using a data-assimilated simulation. A remarkable advance in the understanding of subduction/ obduction is brought by the finding that the high-frequency MLD variability associated with mesoscale eddies can greatly enhance subtropical subduction, particularly for the mode The orogenesis followed a succession of characteristic stages, subduction, obduction, collision and hypercollision with back-thrusting that led to the construction of the orogenic wedge. Apr 1, 2020 · Subduction/obduction is the vital component of ocean circulation in the upper ocean. KANGARLI8, A. Exhumation of HP to UHP rocks requires the weakening of Feb 15, 2012 · Abstract Ventilation, including subduction and obduction, for the global oceans was examined using Simple Ocean Data Assimilation (SODA) outputs. Although dense oceanic rocks are destroyed usually by subduction in ocean trenches, less commonly large heavy slabs are uprooted, detached, and moved across less dense continental crust. It is worthwhile to emphasize that the concept of subduction/obduction applies to water mass formation/ erosion in the open ocean only. Oct 30, 2018 · It should also be noted that MOR lithosphere is buoyant, so it is important to understand whether or not compression of such lithosphere can lead to sustainable subduction. The subducting oceanic slab penetrates through the mantle, interacts with multiple phase Feb 24, 2021 · In accretionary convergent margins, the subduction interface is formed by a lower plate décollement above which sediments are scraped off and incorporated into the accretionary wedge. The annual subduction/obduction rates vary greatly on the Jan 1, 1999 · They are interpreted as deeper level metamorphosed continental margin sedimentary rocks exhumed by out-of-sequence thrusting placing granulites over mantle sequence harzburgites during the later stages of obduction. When slivers of continental crust and sediments enter a subduction zone, they may be scraped off at shallow levels (e. This place is known as a subduction zone. Ventilation of a monsoon-dominated ocean: subduction and obduction in the North Indian Ocean. F. A subduction–obduction processes during the Late Cretaceous–early Tertiary in the eastern and western Alps to be specified. Abstract In the Lesser Caucasus three main domains are distinguished from SW to NE: (1) the autochthonous South Armenian Block (SAB), a Gondwana-derived terrane; (2) the ophiolitic Sevan–Akera suture zone; and (3) the Eurasian plate. Tauru 2000 km Le Pichon et al 1988 Figure 1. Enhancement of subduction/obduction due to hurricane-induced mixed layer deepening. Subductions, obduction and collision in the Lesser Caucasus (Armenia, Azerbaijan, Georgia), new insights M. , 2016; Marshall et al. May 1, 2014 · Since subduction initiation and obduction can develop over thousands of km along strike (as shown by the examples of the Neotethys, during both the Late Jurassic and Late Cretaceous, or Papua), one may wonder if the blocking threshold at S needs to be integrated over the whole length of the incipient subduction zone, or if a local instability Trenches form where the subducting plate begins its descent and can be as much as 11 kilometers (7 miles) deep. Supposing obduction occurs, we get what's called an ophiolite. , 1985a). 6% over the past 50 years, while the Mar 9, 2018 · Liu Chengyan. , 1996 Aug 10, 2013 · The Philippine archipelago resulted from a complex series of geologic events that involved continental rifting, oceanic spreading, subduction, ophiolite obduction, arc-continent collision, intra-arc basin formation and strike-slip faulting. To isolate the subduction effect, for simplicity, in this conceptual May 19, 2023 · Current models invoke subduction initiation at a mid-oceanic ridge located sufficiently close to the Arabian passive margin to allow initiation of continental subduction below the ophiolite within May 31, 2018 · For the effective trajectory, subduction (obduction) is calculated according to equation 1 (2). In addition, the time window for subduction/obduction and the distribution of subducted/obducted water in the ocean interior are explored Jun 1, 2023 · While the early Cretaceous in the southern segment is characterized by the initial obduction of ophiolites, the Late Cretaceous in the entire zone is marked by the underthrusting of the Arabian passive margin, coinciding with the obduction of Cretaceous ophiolites on the overriding plate and the subsequent subduction of stretched and denser May 1, 2016 · Subduction processes play a major role in plate tectonics and the subsequent geological evolution of Earth. 2001;Gautier et al. 5 is based on spreading rates obtained from the central Atlantic magnetic anomalies which allow the opening of the Alpine Tethys to be defined. 4 e), soon (c. Two. The subduction process is credited with being the single, largest contributor behind the theory of plate tectonics. Chinese Journal of Oceanology and Limnology, 34 (4): 835–846. 2 Sv occurring during winter monsoon period and 6 Sv/4. Apr 1, 2024 · The impact of the Reunion plume resulted in the obduction of ITSZ ophiolites at the northern margin and the Pakistan ophiolites at the northwestern margin. This new method can provide the three-dimensional feature of Nov 30, 2022 · Significance Statement The annual mean subduction/obduction rate is a term quantifying the large-scale irreversible downward/upward water transport between the mixed layer and the permanent Jan 1, 2010 · Following the subduction of oceanic lithosphere remnants under Eurasia, the collision of the SAB with Eurasia started during the Paleocene, producing 1) folding of ophiolites, arc and Upper Cretaceous formations (Transcaucasus massif to Karabakh); 2) thrusting toward SW; and 3) a foreland basin in front of the belt. Subduction of the Arabian continental crust beneath the obducting Semail ophiolite to ∼78–90 km depth has been proven by Published in ! which should be cited to refer to this work. , Casey and Dewey, 1984; Pearce et al. May 26, 2016 · This paper aggregates the main basic data acquired along the Chile Triple Junction (CTJ) area (45°–48°S), where an active spreading center is presently subducting beneath the Andean continental margin. The role of sea surface wind in “subduction” rate variation in north pacific. Four‐dimensional dynamic analog subduction Apr 23, 2008 · On the other hand, McCartney and Talley, McCartney, and Paillet and Arhan showed subduction in the eastern subtropical gyre for these light density classes, 27. From its onset, however, subduction has progressively consumed most of the Sep 1, 2022 · These subduction-collision systems exhibit the characteristics of accreted and deformed island arcs, (ultra) high-pressure (UHP) metamorphism, and ophiolites that may allow constraining plate tectonic evolution in deep geological time (e. , 2014; van Hinsbergen et al. Although the Spong arc shows many similarities to the andesitic Dras arc within the Indus suture zone, structural, tectonic, and palaeomagnetic Mar 6, 2018 · Many mountain ranges around the world were created in this manner. It can be divided into two tectono-stratigraphic blocks, namely; the Palawan-Mindoro Continental Block (PCB) and the Philippine Mobile Belt (PMB). Thick layers of sediment may accumulate in the trench, and these and the subducting plate rocks contain water that subduction transports to depth, which at higher temperatures and pressures enables melting to occur and 'magmas' to form. Our geochemical data suggest that the ophiolite had formed in Oct 1, 1998 · subduction–obduction processes during the Late Cretaceous –early Tertiary in the eastern and western Alps to be specified. , the Kerguelen (130–110 Ma), Marion (90–84 Ma), and Reunion (65–70 Ma)] (Bandyopadhyay et al. The global subduction rate averaged over the period from 1959 to 2006 is estimated at 505. Furthermore, the annual subduction/obduction rate enhancement induced by . , 2018). The Philippine archipelago resulted from a complex series of geologic events that involved continental rifting, oceanic spreading, subduction, ophiolite obduction, arc-continent collision, intra-arc basin formation and strike-slip faulting. The annual subduction/obduction rates vary greatly on the Old, cold sea floor goes down subduction zones beneath warmer sea floor or continent, but what happens when a high-floating continent or island arc tries to go down a trench under another continent or island arc? The answer is obduction, a BIG collision. When two tectonic plates collide, one plate is forced down under the other one. The Oman and other remarkable Tethyan obductlons in the Apr 27, 2011 · We establish the ‘subduction initiation rule’ (SIR) which predicts that most ophiolites form during subduction initiation (SI) and that the diagnostic magmatic chemostratigraphic progression for SIR ophiolites is from less to more HFSE-depleted and LILE-enriched compositions. , 2007; Kimura et al. The place where subduction has occurred, however, does not result in the formation of mountains. ROLLAND1, C. t1cs 2cm. The plate forced down is being subducted while the plate forced up is obducted. This causes the oceanic plate to buckle and usually results in a new mid-ocean ridge forming and turning the obduction into subduction. This special issue focuses on ongoing research in subduction dynamics to a large extent (oceanic subduction, continental subduction, obduction…) for both past and active subduction zones and into mountain building processes and the early evolution of orogens. J. A later phase of higher-level shearing deformation with SW (continentward) vergence, during the Campanian, accompanied the thrusting of the Hawasina Nappes and the obduction of the Semail Jul 15, 2019 · Tectonic model of subduction initiation along the Arabian margin of Oman. Therefore, we impose a tapered decrease in trench length between Aug 30, 2020 · Oxygen obduction (O ox) is defined here as the opposite of subduction, that is, the oxygen flux from the permanent thermocline through the steady, late winter ML base into the seasonal thermocline/ML (Kwon et al. The global subduction rate averaged over the period from This study is focused on re fining the three-dimensional features of subduction/obduction and providing a more accurate distribution of the annual subduction/obduction rate in the density space. Nittany near Penn State's University Park campus, and all of the May 31, 2018 · The annual subduction/obduction rate in the North Indian Ocean based on SODA is estimated at 10. (2012). interior ocean. Subduction takes place mainly in the subtropical basin where et al. DANELIAN3, R. SOSSON1*, Y. Ophiolite obduction Jan 7, 2016 · Lateral induction is the dominant contributor to enhancement of subduction/obduction, and temporal change of mixed layer depth has a secondary role. Only the Western and Central Alps are considered here, the latter are represented by the Matterhorn transect whose outcrop geology and deep structure are well Oct 20, 1985 · Incipient subduction, and obduction, of the oceanic and sub-oceanic crust are observed along the suture line with the occurrence of numerous N-S trending, fault-bounded ridges and troughs. The principal problem is that almost all oceanic crust older than about 200 million years has been obliterated by subduction. Aug 10, 2013 · The Philippine archipelago resulted from a complex series of geologic events that involved continental rifting, oceanic spreading, subduction, ophiolite obduction, arc-continent collision, intra-arc basin formation and strike-slip faulting. The datasets2. In particular, earthquakes larger than a moment magnitude, M (Box 1 Jan 7, 2016 · Lateral induction is the dominant contributor to enhancement of subduction/obduction, and temporal change of mixed layer depth has a secondary role. (1986) Middle Miocene obduction and late Miocene beginning of collision registered in the Hengchun Peninsula: geodynamic implications for the evolution of Taiwan,Memoir of the Geological Society of China 7, 301–324. Further analysis indicates that the high Oct 1, 1995 · Abstract Ventilation in the North Atlantic and North Pacific is examined by analyzing the Levitus climatological data and the Hellerman and Rosenstein wind stress data. Subduction is the key channel transporting the atmospheric signals and bio-chemical elements into the thermocline, affecting the subsurface ocean; while sites of obduction, the opposite process, are important windows opened up for the interior oceanic signals and tracers to be transferred to the air-sea interface. The rupture could have been intra-oceanic and induced the onset of ocean–ocean subduction. It is revealed that besides the winter season, ventilation can also occur in summer. Reconstruction of the Zagros margin following McQuarrie and van Hinsbergen (2013), and of eastern Mediterranean subduction initiation and obduction following Maffione et al. The SCS is located under the influence of strong seasonal cycle of the East Asian monsoon; therefore, the oceanic circulation and thermohaline structure This tectonometamorphic event was related to partial subduction of the northeast corner of the Arabian platform beneath the neo-Tethyan oceanic lithosphere. 7 which have occurred along the zone are consistent with 3 days ago · Salt Lake Community College via OpenGeology. Mar 8, 2021 · The interplay between continental subduction exhumation dynamics and the obduction of ophiolite sheets remains enigmatic. Here, the authors show that the extrusion of the subducted continental Jun 30, 2007 · Continental subduction, as the Arabian margin reaches the trench at approx. Plate subduction and collision zone is one of the most active tectonic regimes on the Earth, which controls the mass and energy circulation between the Earth’s surface and interior, produces the majority of volcanoes and earthquakes, and is strongly correlated with the generation of mineral resources. 4 f). Finally, the annual subduction (obduction) rate is obtained by summing S winter (O winter) and S summer (O summer) at this station. Stommel (1979) postulated a simple conceptual model, in which the processes involved in the Aug 12, 2021 · Continental collisions commonly involve highly curved passive plate margins, leading to diachronous continental subduction during trench rollback. , 2010, 2012). a. 2018. Jun 25, 2015 · The roles of continental crust thickness, passive margin length, subducting lithosphere thickness, and overriding plate thickness were investigated to determine the maximum continental subduction depth, maximum forearc obduction distance, and forearc deformation during continental subduction. Jun 16, 2020 · A dextral oblique convergence model has been proposed by several authors for the emplacement of the subduction-obduction complex of New Caledonia (Cluzel et al. During subduction, the basal décollement is typically located within or at the base of the sedimentary pile. It shows a halt of 19. , 1984; Stern, 2005; Ernst et al. Subduction/obduction in different areas are dominated by different physical processes. Ventilation between the permanent pycnocline and the overlying seasonal pycnocline and mixed layer consists of two physical processes: subduction and obduction. Jun 25, 2015 · Laboratory models of subduction and late-stage continental subduction from Edwards et al. , Houseman and Molnar, 1997) dubbed here Feb 1, 2012 · Ventilation, including subduction and obduction, for the global oceans was examined using Simple Ocean Data Assimilation (SODA) outputs. 8 Sv (1 Sv ≡ 106 m3 s−1), while the corresponding global obduction rate is estimated at 482. Qingdao: Ocean University of China. , 2011. Continental subduction takes place in the final stage of subduction when all oceanic lithosphere is consumed and continental passive margin is pulled into the mantle. 8 Sv during summer monsoon period, respectively. BABAZADEH7, T. during the later stages of obduction. The Cascadia subduction zone is a 960 km (600 mi) fault at a convergent plate boundary, about 100–200 km (70–100 mi) off the Pacific coast, that stretches from northern Vancouver Island in Canada to Northern California in the United States Nov 8, 2019 · Subduction/ obduction rate in the North Pacific diagnosed by an eddyresolving model. A collisional emplacement of the Western Alps ophiolites was 'advocated by Auzende et ai. Less frequent than “normal” subduction, obduction is a first order process that remains enigmatic. Obduction can also be compared to collision, since both processes create large thrust slabs of crystalline rocks (Armstrong and Dick, 1974). Convergent boundaries, also called destructive boundaries, are places where two or more plates move toward each other. 3, based on maps of isopycnal properties; these outcrops are in a net Ekman downwelling region, which therefore yields net wind-driven subduction, not obduction. , 1993; Sallée et al. The onset of Alpine subduction is supposed, but without consensus, to have resulted from rupture localized at the foot of the Apulia continental margin. 2016;Cluzel et Nov 30, 2017 · The simplest form of this type of obduction may follow from the development of a subduction zone near the continental margin shown in figure 1A. Furthermore, the annual subduction/obduction rate enhancement induced by tropical cyclones in the North Pacific, defined as the difference between the annual subduction/obduction rate for the cases subduction/obduction in the winter monsoon season (Liu et al. The definition of subduction is the process that occurs when two tectonic plates meet at Oct 27, 2022 · According to NCRB Crime in India Report 2021, India reported 1,01,707 cases of kidnapping and abduction. Cowan & Silling 1978), subducted to depths of up to 100–200 km and then exhumed as high pressure (HP) and ultra-high pressure (UHP) rocks (Liou et al. , 2013, Dilek and Furnes, 2011, Ghose et al Jun 25, 2015 · Thus, our experiments investigate subduction, continental subduction, and obduction processes in a confined upper mantle reservoir, isolated from any other processes. Over time, subduction leads to complete closure of ocean basins and eventually to collision of continental plates. Above and behind the subduction zone, a welt of oceanic crust and mantle rides up over the descending plate. HP–LT metamorphism record a long-lasting history of oceanic Jun 1, 2011 · The annual subduction rate averaged from 2001 to 2004 is estimated at 49. 4. Intra-oceanic subduction started in the South Loyalty Basin, as indicated by high-temperature amphibolite (56 Ma), boninite and adakite series dykes (55–50 Ma) and changes in the sedimentation regime (55 Ma). Jan 1, 1999 · Tectonic model for the subduction-obduction evolution of the Oman ophiolite in the southeastern Oman Mountains, after Searle et al. 1 Subduction and its Variability in the North Indian Ocean This tectonometamorphic event was related to partial subduction of the northeast corner of the Arabian platform beneath the neo-Tethyan oceanic lithosphere. They showed that the mechanisms for mode water subduction and subduction/obduction patterns across mode water density ranges are well reproduced in this model. Subduction zones form where a plate with thinner (less-buoyant) oceanic crust descends beneath a plate with thicker (more-buoyant) continental crust. This chemostratigraphic evolution reflects formation of what ultimately becomes forearc lithosphere as a result of Jul 5, 2011 · This paper presents a synthetic view of the geodynamic evolution of the Zagros orogen within the frame of the Arabia–Eurasia collision. 2018, 2020).
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