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Chiyue Huang - One of the best experts on this subject based on the ideXlab platform.

  • From convergent plate margin to Arc-Continent Collision: Formation of the Kenting Mélange, Southern Taiwan
    Gondwana Research, 2016
    Co-Authors: Xinchang Zhang, Chiyue Huang, Peter A. Cawood, Yuejun Wang, Yi Yan, M. Santosh, Wenhuang Chen
    Abstract:

    Abstract The Kenting Melange on the Hengchun Peninsula, Taiwan, formed through tectonic shearing of subduction complex lithologies, probably within the plate boundary subduction channel between the Eurasian and Philippine Sea plates, with further deformation and exhumation in the Pliocene–Pleistocene during arc–continent Collision. Field relations reveal a structural gradation from normal stratified turbidite sequence (Mutan Formation) through broken formation to highly sheared Kenting Melange containing allochthonous polygenic blocks. This gradation is consistent with an increase of average vitrinite reflection values from ~ 0.72% in the Mutan Formation through ~ 0.93% in the broken formation to ~ 0.99% in the melange, suggesting temperatures of at least 140 °C during formation of the Kenting Melange. Zircons from gabbro in the Kenting Melange are dated as 25.46 ± 0.18 Ma, which together with geochemical data constrains the source to South China Sea oceanic lithosphere. In combination with the field relationships, vitrinite reflectance values, microfossil stratigraphy, and offshore geophysical data from S and SE Taiwan, we propose that the Kenting Melange initially formed at the subduction plate boundary from off-scraped trench deposits. Minor Plio–Pleistocene microfossils (

  • tectonic features of the incipient arc continent Collision zone of taiwan implications for seismicity
    Tectonophysics, 2009
    Co-Authors: Andrew Lin, Shu-kun Hsu, Bochu Yao, Charshine Liu, Chiyue Huang
    Abstract:

    Abstract Southern Taiwan and its offshore area lie in the region where the Luzon volcanic arc initially collides with the rifted China continental margin. Because of the incipient Arc-Continent Collision, the structures vary markedly along-strike the Collision zone so as the patterns of seismicity. We use new seismic reflection profiles and integrate existing data to reveal major tectonic features and potential seismogenic faults of the study area. The accretionary wedge in the incipient Arc-Continent zone can be divided into the lower slope, upper slope, and backthrust domains, respectively. These structural domains reflect different aspects of wedge deformation, and exhibit significant structural variations along-strike. Reflection seismic data show that the prominent seismogenic structures in the Taiwan incipient Collisional wedge include: (1) frontal decollement beneath the lower-slope domain, (2) out-of-sequence thrusts bordering the lower-slope and upper-slope domains, (3) megathrust that cuts into the oceanic (?) basement beneath the upper-slope domain, and (4) the Chaochou-Hengchun faults in the onshore upper-slope domain. Thermal regime for those structures indicates that the megathrust and part of frontal decollement are seismogenic. The geometry of the frontal decollement, out-of-sequence thrusts and megathrust is analogous to those observed along the Nankai prism of Japan, so that they are possibly capable of generating great earthquakes as shown in the Nankai Trough. Beneath the lower and upper-slope domains off SW Taiwan, the seismicity is characterized by mantle earthquakes with the accretionary wedge being largely aseismic. We interpret the lack of prominent seismicity within the accreted wedge to result from excess fluid pressure that has significantly weakened the wedge materials and fault zones and therefore results in less seismicity. The predominant mantle earthquakes beneath the accretionary wedge, however, may result from water-enriched mantle materials infiltrated during previous Mesozoic subduction event and later rift events. The volatile contents may have significantly reduced the rigidity of the mantle, leading to the mantle being more susceptible for brittle deformation and hence anomalously high seismicity.

  • Temporal and spatial records of active Arc-Continent Collision in Taiwan: A synthesis
    Geological Society of America Bulletin, 2006
    Co-Authors: Chiyue Huang, Peter B. Yuan, Shuh-jung Tsao
    Abstract:

    Well-documented stratigraphy and clearly defined geodynamics in Taiwan, where some of the best records on Arc-Continent Collision have been preserved, offer a unique example for the study of Collision belts worldwide. The oblique Arc-Continent Collision in Taiwan caused a simultaneous and sequential migration of four tectonic processes. Beginning from 16 to 15 Ma, subduction of the South China Sea oceanic crust beneath the Philippine Sea plate resulted in volcanism in the Coastal Range and formation of an accretionary prism in the Central Range. Beginning in the latest Miocene–earliest Pliocene, the subduction was followed by initial Arc-Continent Collision, as supported by the following: unroofing and erosion of the deformed accretionary prism, and deposition of sediments thus derived in the adjacent accretionary forearc (5 Ma) and slope basins (4 Ma); waning of volcanism (north, 6–5 Ma; south, 3.3 Ma); buildup of fringing reefs on the gradually quiescent volcanoes (north, 5.2 Ma; south, 2.9 Ma); arc subsidence by strike-slip faulting and the development of pull-apart intra-arc basins (north, 5.2–3.5 Ma; south, 2.9–1.8 Ma); thrusting of forearc sequences to generate a Collision complex starting from 3 Ma; and clockwise rotation of the arc-forearc sequences (north, 2.1–1.7 Ma; south, 1.4 Ma). The Collision propagated southward and reached southern Taiwan by 5 Ma, as evidenced by the successive deformation of the associated accretionary wedge en route. Afterward, the advanced Arc-Continent Collision stage appeared in the earliest Pleistocene, as marked by the westward thrusting and accretion of the Luzon arc-forearc against the accretionary wedge (north, 1.5 Ma; south, 1.1 Ma) and exhumation of the underthrust Eurasian continent rocks (north, 2.0–1.0 Ma; south, 1.0–0.5 Ma). The final stage of the tectonic process, arc collapse-subduction, began by 1 Ma off the northern Coastal Range. The geologic records compiled and presented in this study strongly support the scenario of a continuous southward migration of tectonic processes and a change in sediment source and structural style. Most importantly, the model has a broad potential for reconstructing and predicting the evolution of Arc-Continent Collision through space and time.

  • Structural evolution from Paleogene extension to Latest Miocene-Recent Arc-Continent Collision offshore Taiwan: comparison with on land geology
    Journal of Asian Earth Sciences, 2001
    Co-Authors: Chiyue Huang, Peter B. Yuan, Kanyuan Xia, Pu-gang Chen
    Abstract:

    Marine structures observed in seismic profiles across the NE South China Sea-Taiwan Strait-Luzon Arc region show that they are comparable to those observed onshore Taiwan. The Hanjiang Depression and Dongsha Uplift off the SE China coast extend to the Penghu Basin and Penghu Platform, respectively, in the Taiwan Strait, while the Tainan Basin in the south of Penghu Platform is connected to the Chaoshan Depression south of the Dongsha Uplift. The Hanjiang Depression and the Penghu Basin are composed of Paleogene syn-rift sequences on the Mesozoic basement and are uncomformably overlain by Neogene post-rift strata. Similar successions are found underneath the coastal plain or have been thrust up as a fold-and-thrust belt bordering the Peikang Basement High onshore central Taiwan. East of the Manila Trench, off southwestern Taiwan, parts of the Tainan Basin are thrust into the submarine syn-Collision accretionary wedge (the fold-and-thrust Kaoping Slope) in the initial Arc-Continent Collision zone. They have also been exposed in the fold-and-thrust Western Foothills south of the Peikang Basement High in southern Taiwan during an advanced stage of Arc-Continent Collision since the Late Pliocene. Further east, the pre-Collision accretionary wedge (the Hengchun Ridge) shoals northward to the Hengchun Peninsula, with Late Miocene turbidites unconformably overlain by Plio-Pleistocene shallow-marine slope basin sequences. In the arc domain, cast of the arc-prism boundary fault, the western forearc sequences in the North Luzon Trough are deformed. Two normal-faulted intra-arc basins occur on the eastern part of the Lanhsu Island in the Luzon Arc. The scenario of the deformed forearc sequences and the development of the two intraarc basins in the initial Arc-Continent Collision zone are analogous to the Lichi Melange-Taiyuan Basin and the intra-arc basins in the southern Coastal Range, eastern Taiwan. Additionally, the lateral change in the marine structure from the passive Asian continental margin to the Manila subduction system is comparable to the temporal evolution from Paleogene normal faulting, through Neogene subduction, to Latest Miocene-Recent are-continent Collision observed onshore Taiwan. (C)) 2001 Elsevier Science Ltd. All rights reserved.

  • Geodynamic processes of Taiwan arc–continent Collision and comparison with analogs in Timor, Papua New Guinea, Urals and Corsica
    Tectonophysics, 2000
    Co-Authors: Chiyue Huang, Peter B. Yuan, Ching Weei Lin, Tan K. Wang, Chung-pai Chang
    Abstract:

    Abstract The Taiwan arc–continent Collision involves four geodynamic processes: intra-oceanic subduction; initial arc–continent Collision; advanced arc–continent Collision; and arc collapse/subduction. These processes now occur simultaneously in 19–24°30′N but have operated sequentially southward since the Late Miocene. Although the geological and geophysical features appear to change progressively from north to south across the island, they are distinct within individual tectonic regimes. Using the present scenario as a basis for comparison, it is suggested that Timor is at the initial arc–continent Collision stage, while Papua New Guinea and Urals proceeded to the advanced arc–continent Collision stage. However, Corsica represents an even more advanced stage than in Taiwan, where a previously accreted arc has collapsed and been totally removed.

Dennis Brown - One of the best experts on this subject based on the ideXlab platform.

  • Serpentinization of the fore-arc mantle along the Taiwan Arc-Continent Collision of the northern Manila subduction zone inferred from gravity modeling
    Tectonophysics, 2016
    Co-Authors: Wen-bin Doo, Dennis Brown, Hao Kuo-chen, Shu-kun Hsu, Yin-sheng Huang
    Abstract:

    Abstract Serpentinized peridotite in the fore-arc has been observed in a number of subduction zones, including the northern Manila subduction zone which terminates northward in the Taiwan Arc-Continent Collision. How this zone of serpentinization changes northward from the subduction of thinned continental lithosphere to full Arc-Continent Collision in the Taiwan orogeny is not well known. In this paper we present 2-D gravity modeling along three P-wave (Vp) transects across the Taiwan orogeny. Two of these transects were collected with ocean-bottom seismometers. These two transects provide good constraints on the velocity structure to the west of, and on land, southern Taiwan. Conversion of Vp to density in this area allows us to model the gravity anomaly with very little misfit. Along the subduction zone, however, the velocity models are poorly constrained in the upper mantle, where an anomalous density unit has to be used in order to model the short wavelength gravity anomaly in this area. A third transect across central Taiwan that is derived from the TAIGER local tomography data, provides good control on the crust and upper mantle Vp structure that we use to place provide density constraints for modeling the gravity anomaly in this part of the Collision zone. In order to model the short wavelength gravity anomaly across the Longitudinal Valley and the southern Longitudinal trough, an anomalous density block is required beneath the fore-arc region. We interpret that the source of this anomalous density material could be serpentinized fore-arc mantle, similar to what is interpreted for the northern Manila subduction zone farther south. Water released from the subduction of the extended crust of the continental margin results in the serpentinization of the fore-arc area and may be driving the uplifting of the high-pressure rocks.

  • Processes of Arc–Continent Collision in the Uralides
    Frontiers in Earth Sciences, 2011
    Co-Authors: Dennis Brown, Richard Herrington, Joaquina Alvarez-marrón
    Abstract:

    The Uralide Orogen of Russia contains well-preserved examples of Paleozoic arc–continent Collisions. The Tagil Arc in the Middle Urals formed as an intra-oceanic arc from the Late Ordovician through the Devonian and appears to have collided with the continental margin of Laurussia in the Early Carboniferous. The Magnitogorsk Arc in the South Urals formed in an intra-oceanic setting from the Early Devonian to the Middle Devonian and collided with the margin of Laurussia in the late Middle and through the Late Devonian. The ourcropping geology of the South Urals, together with an extensive geochronological, geochemical, and geophysical dataset allows a detailed reconstruction of the arc–continent Collision that took place in this part of the Urals. This reconstruction provides important insights into arc–continent Collision processes through time, as well as into the growth and destruction of the continental crust during arc–continent Collision.

  • Arc–Continent Collision: The Making of an Orogen
    Frontiers in Earth Sciences, 2011
    Co-Authors: Dennis Brown, P. D. Ryan, Juan Carlos Afonso, David Boutelier, Jean-pierre Burg, Timothy B. Byrne, Andrew J. Calvert, F. Cook, Susan M. Debari, John F. Dewey
    Abstract:

    There is no one model, no paradigm, that uniquely defines arc–continent Collision. Natural examples and modelling of arc–continent Collision show that there is a large degree of, and variation in, complexity that depend on a number of key first-order parameters and the nature of the main players; the continental margin and the arc–trench complex (the arc–trench complex includes the arc and the subduction zone). Although modelling techniques can be used to gain insights into these, they cannot and do not aim at reproducing the messiness of nature. In natural examples, identifying the nature of the main players involved, such as the age, physical properties, and pre-existing structure of the margin and the arc is just a beginning. Once this is done, parameters such as time, convergence velocity and vector need to be taken into account when determining the tectonic processes that were operative in any one arc–continent Collision. In active examples, such as those in the southwest Pacific, some of these first-order parameters can be readily determined, and the nature of the main players easily assessed. Fossil arc–continent Collisions, however, have commonly undergone post-Collision deformation, erosion, and possibly partial dispersion to be left outcropping in the middle of a forest, with many of the key ingredients missing or hidden. This leaves the geologist to resort to comparison with other natural examples and with models that are mechanically constrained and simplified reproductions of the process to reconstruct and explain what may have been there and, importantly, what processes may have been operating and when. We attempt to show that this is not an easy task that can be put into one simple model. In this chapter we do not present a model for arc–continent Collision. Instead, we begin with the main players involved, highlighting the characteristics of each that likely have a major influence on an arc–continent Collision. Then, we investigate a range of possible processes that could take place once an intra-oceanic volcanic arc collides with a continental margin.

  • The Generation and Preservation of Mineral Deposits in Arc–Continent Collision Environments
    Frontiers in Earth Sciences, 2011
    Co-Authors: Richard Herrington, Dennis Brown
    Abstract:

    Intra-oceanic volcanic arcs are sites for major magmatic hydrothermal mineral deposits such as porphyry Cu–Mo–Au, epithermal Au–Ag and volcanic hosted massive sulfide (VMS) deposits. Arc magmas are largely generated from the mantle wedge as it reacts with components rising from the subducted slab. Variations in the tectonic framework of the arc, the nature of subduction and the components interacting with the mantle wedge will obviously have a direct effect on mineral deposit formation processes and the type of deposit resulting. Most mineral deposits found in fossil arc–continent Collision zones are those that were formed in intra-oceanic subduction settings and which have been preserved as a result of the arc–continent Collision event. Others appear to form either during the Collision event or following it as the subduction zone changes polarity or jumps to a new position. At the loci of arc–continent Collision, the first effects that may be seen are due to the ingress of continental material to the subduction channel. This may change the budget of contributed components from the slab to the mantle wedge and in some cases it appears that magmas enriched in metals such as gold could be generated. There is also some evidence that the physical effect of the ingress of the less dense continental crust itself could cause subduction shallowing or even stalling. Shallowing or stalling can lead to the generation of K-rich magmas which have been linked to the generation of magmatic Cu and Au deposits. During the Collision, obduction of ophiolites from the overlying oceanic plate is a common feature and this may be accompanied by accretion of parts of, or even the entire volcanic arc. This will result in the preservation of mineral deposits such as ophiolitic Cr and VMS deposits that had already formed in the intra-ocean environment accreted to the continental margin. Arc reversal is a feature in some arc–continent Collisions, and this effectively turns passive continental margins into sub continental subduction margins with an active continental arc. Continental arcs are important sites for porphyry Cu–Mo–Au and epithermal Au–Ag deposits and the arc reversal may result in melts being sourced from more fertile, previously metasomatised mantle resulting in larger and higher grade Cu and Au deposits. The actual Collision itself is shown to result in the formation of orogenic gold deposits in some cases and finally post-Collision extension can lead to the formation of VMS deposits in favourable settings.

  • The growth and destruction of continental crust during arc–continent Collision in the Southern Urals
    Tectonophysics, 2009
    Co-Authors: Dennis Brown
    Abstract:

    Abstract The Southern Urals of Russia contain a well preserved example of a Paleozoic arc–continent Collision in which the Laurussia margin was subducted beneath the Magnitogorsk island arc in the Devonian, providing an ideal field area for studying the possible growth and destruction of the continental crust during this process. High-pressure rocks derived from the leading edge of the continental margin indicate that it was subducted to a depth of between 70 km (eclogite assemblages) and 120 km (micro diamonds). The vast majority of the high-pressure rocks have a sedimentary protolith, with mafic eclogite having been derived from dikes intruding into the sediments. High-pressure rocks derived from the mafic ganulite that currently makes up the middle and lower crust of the Southern Urals do not occur in outcrop, suggesting that much of the subducted margin remained in the upper mantle. However, extensive geological, geochemical, and geophysical data do not unequivocally clarify its subsequent fate. Crustal delamination and foundering into the mantle can be ruled out, and recycling through the volcanic arc system appears to have been minor. While the metamorphic products of subducted continental crust can remain in the mantle for long periods of time, in the Southern Urals it has not been imaged by the available geophysical data sets. A possible explanation for this is that the progressive metamorphism of mafic granulite to eclogite assemblages would have altered its physical properties to those of typical mantle lithologies, making them difficult to detect by geophysical methods. It is estimated that the volume of continental crust that was subducted and lost to the mantle was approximately one third of the volume that was added to the Laurussia margin by the accretion of the Magnitogorsk arc.

Charshine Liu - One of the best experts on this subject based on the ideXlab platform.

  • tectonic features of the incipient arc continent Collision zone of taiwan implications for seismicity
    Tectonophysics, 2009
    Co-Authors: Andrew Lin, Shu-kun Hsu, Bochu Yao, Charshine Liu, Chiyue Huang
    Abstract:

    Abstract Southern Taiwan and its offshore area lie in the region where the Luzon volcanic arc initially collides with the rifted China continental margin. Because of the incipient Arc-Continent Collision, the structures vary markedly along-strike the Collision zone so as the patterns of seismicity. We use new seismic reflection profiles and integrate existing data to reveal major tectonic features and potential seismogenic faults of the study area. The accretionary wedge in the incipient Arc-Continent zone can be divided into the lower slope, upper slope, and backthrust domains, respectively. These structural domains reflect different aspects of wedge deformation, and exhibit significant structural variations along-strike. Reflection seismic data show that the prominent seismogenic structures in the Taiwan incipient Collisional wedge include: (1) frontal decollement beneath the lower-slope domain, (2) out-of-sequence thrusts bordering the lower-slope and upper-slope domains, (3) megathrust that cuts into the oceanic (?) basement beneath the upper-slope domain, and (4) the Chaochou-Hengchun faults in the onshore upper-slope domain. Thermal regime for those structures indicates that the megathrust and part of frontal decollement are seismogenic. The geometry of the frontal decollement, out-of-sequence thrusts and megathrust is analogous to those observed along the Nankai prism of Japan, so that they are possibly capable of generating great earthquakes as shown in the Nankai Trough. Beneath the lower and upper-slope domains off SW Taiwan, the seismicity is characterized by mantle earthquakes with the accretionary wedge being largely aseismic. We interpret the lack of prominent seismicity within the accreted wedge to result from excess fluid pressure that has significantly weakened the wedge materials and fault zones and therefore results in less seismicity. The predominant mantle earthquakes beneath the accretionary wedge, however, may result from water-enriched mantle materials infiltrated during previous Mesozoic subduction event and later rift events. The volatile contents may have significantly reduced the rigidity of the mantle, leading to the mantle being more susceptible for brittle deformation and hence anomalously high seismicity.

  • destruction of luzon forearc basin from subduction to taiwan arc continent Collision
    Tectonophysics, 2009
    Co-Authors: Justin Hirtzel, Charshine Liu, Wu-cheng Chi, Donald L. Reed, Liwen Chen, Neil Lundberg
    Abstract:

    Abstract Along offshore to the east of southern Taiwan, different stages of subduction and Collision occur simultaneously along strike of the convergent boundary. As a result, the evolution of the Luzon arc and its forearc basin can be studied from the younger subduction zone to the south to the Collision zone to the north. Examining more than 8000 km of seismic lines, we analyzed the seismic stratigraphy of strata in a forearc basin and its successive basins in the Collision zone, to study the processes related to arc collapse and forearc basin closure. The study area presents three evolutional stages: intra-oceanic subduction, initial arc–continent Collision, and arc–continent Collision. We divided 9 seismic sequences in the forearc basin and found older, sub-parallel basin-fill sequences (4–9) and younger, divergent sequences (1–3). Isochron maps of the sequences were used to interpret different deformation modes and their areal extends. On the arc side of the basin of the subduction and initial Collision zones, we found relatively undisturbed strata, showing little arc deformation. On the trench side, the growth strata in sequences 1 through 3 are the result of recent tectonic wedging along the rear of the accretionary prism. Tectonic wedging and back-thrusts incorporate the forearc strata into the rear of the accretionary prism until they close the forearc basin at a region with a 2200 m basement relief. This relief is not caused by active deformation, as young flat forearc strata lap onto it and mark the transition from initial Collision to Collision where many growth strata to the north suggest abrupt increase in active arc basement deformation. The (1) deforming basement, (2) back-thrusts, and (3) other sedimentary processes affect the architecture of the successive basins in the Collision zone until the arc is juxtaposed to the rear of the fold and thrust belt on land.

  • geological controls on bsr occurrences in the incipient arc continent Collision zone off southwest taiwan
    Marine and Petroleum Geology, 2009
    Co-Authors: Chechuan Lin, Andrew Lin, Charshine Liu, Guanyu Chen, Weizhi Liao, Philippe Schnurle
    Abstract:

    Bottom simulating reflectors (BSRs) observed on seismic sections are often considered as indicators for the existence of free gas, delineating the base of the gas hydrate stability zone. Abundant BSRs seen on seismic sections acquired off the SW coast of Taiwan indicate the likely and prevalent existence of gas hydrates in the study area. This study aims to characterize the occurrence of BSRs off SW Taiwan and to understand their relationship to topography, tectonic activity, and possible migration paths of gas- bearing fluids in this area. The tectonic setting off SW Taiwan is during the initial stage of Arc-Continent Collision between the Luzon arc and the northeastern continental margin of the South China Sea. A series of west-vergent, imbricated folds and emergent thrusts develop in the accretionary wedge. Each fold-and-thrust sequence corre- sponds to an elongated submarine ridge if its crest is not buried by flat-lying sediments. By contrast, normal faulting prevails in the northeastern margin of the South China Sea. A correlation between distribution of BSRs, topography, and tectonic features can be observed. Four major occurrences of BSR types of ridge type, basin type, submarine-canyon type, and continental slope type, are recognized on the basis of the relationship of BSRs to topographic and structural features. Main characteristics of BSRs in the study area can be described as: (1) they occur mostly beneath topographic highs; (2) a discordant relationship between surfaces of the seafloor and underlying strata where BSRs are present; (3) BSRs are prevalent especially beneath the crest and flank of the upthrusting, large and inclined slope basins; and (4) in general, a series of high-amplitude dipping reflectors beneath BSRs can be found. These features indicate that gas hydrate may accumulate preferably beneath topographic ridges especially underneath four-way-dip topographic closures. This effect may exist because the buoyancy-driven, gas-bearing fluids tend to migrate upward and laterally toward structural highs and their corresponding topographic ridges. The distribution of BSRs indicates that gas hydrates occur more commonly in the accretionary wedge than in the South China continental margin. We suggest that the more widespread occurrence of gas hydrates in the accretionary wedge is due to the existence of multiple fault zones, which may help to tap more deep-seated gas-bearing fluids, in addition to the shallow biogenic gas, in this region.

  • Destruction of Luzon forearc basin from subduction to Taiwan arc–continent Collision
    Tectonophysics, 2009
    Co-Authors: Justin Hirtzel, Charshine Liu, Wu-cheng Chi, Donald L. Reed, Liwen Chen, Neil Lundberg
    Abstract:

    Abstract Along offshore to the east of southern Taiwan, different stages of subduction and Collision occur simultaneously along strike of the convergent boundary. As a result, the evolution of the Luzon arc and its forearc basin can be studied from the younger subduction zone to the south to the Collision zone to the north. Examining more than 8000 km of seismic lines, we analyzed the seismic stratigraphy of strata in a forearc basin and its successive basins in the Collision zone, to study the processes related to arc collapse and forearc basin closure. The study area presents three evolutional stages: intra-oceanic subduction, initial arc–continent Collision, and arc–continent Collision. We divided 9 seismic sequences in the forearc basin and found older, sub-parallel basin-fill sequences (4–9) and younger, divergent sequences (1–3). Isochron maps of the sequences were used to interpret different deformation modes and their areal extends. On the arc side of the basin of the subduction and initial Collision zones, we found relatively undisturbed strata, showing little arc deformation. On the trench side, the growth strata in sequences 1 through 3 are the result of recent tectonic wedging along the rear of the accretionary prism. Tectonic wedging and back-thrusts incorporate the forearc strata into the rear of the accretionary prism until they close the forearc basin at a region with a 2200 m basement relief. This relief is not caused by active deformation, as young flat forearc strata lap onto it and mark the transition from initial Collision to Collision where many growth strata to the north suggest abrupt increase in active arc basement deformation. The (1) deforming basement, (2) back-thrusts, and (3) other sedimentary processes affect the architecture of the successive basins in the Collision zone until the arc is juxtaposed to the rear of the fold and thrust belt on land.

  • Structural evolution and significance of a mélange in a Collision belt: the Lichi Mélange and the Taiwan arc–continent Collision
    Geological Magazine, 2001
    Co-Authors: C. P. Chang, Jacques Angelier, C. Y. Huang, Charshine Liu
    Abstract:

    The analysis of ‘melanges’ of various types (sedimentary, diapiric, tectonic and polygenetic) is generally difficult and depends on a variety of criteria. However, understanding the nature and origin of melanges is crucial to deciphering the evolution of some mountain belts. The Lichi Melange of the Taiwan Coastal Range is juxtaposed against remnant forearc basin sequences by thrust faults and is composed of exotic ophiolite and sedimentary blocks, with sizes ranging from metres to kilometres, and coherent turbidite beds, all embedded in a sheared scaly argillaceous matrix. The Lichi Melange has been interpreted either as a subduction complex, or as an olistostrome. By separating four main deformation levels based on the degree of disruption within the Lichi Melange and adjacent sedimentary rocks, we have made new detailed geological maps and structural profiles in two key areas of the Lichi Melange. We paid particular attention to the original stratigraphic relationships between the melange and the adjacent flysch formation. Our field results compared with submarine seismic profiles suggest that the present-day structure of the Lichi Melange results mainly from the shearing of lower forearc basin sequences, rather than from a subduction complex or a mere olistostrome. In Late Miocene time, because lithospheric subduction turned into arc–continent Collision in the southern Taiwan area, the site of the proto-Manila trench changed from an active plate boundary into a deformation zone with several thrusts. A new plate suture zone between the Eurasian plate (eastern Central Range) and the Philippine Sea plate (Coastal Range) was therefore formed along the Longitudinal Valley. The Longitudinal Valley originated as a submarine arc–prism boundary, an innate weak zone within the overriding plate, and has become a prominent tectonic feature of the arc–continent Collision. This inference is supported by observations on the Lichi Melange in the Coastal Range and the Huatung Ridge off southeastern Taiwan.

A Kuzmichev - One of the best experts on this subject based on the ideXlab platform.

  • neoproterozoic 800 ma orogeny in the tuva mongolia massif siberia island arc continent Collision at the northeast rodinia margin
    Precambrian Research, 2001
    Co-Authors: A Kuzmichev
    Abstract:

    Abstract The Tuva-Mongolia Massif is a composite Precambrian terrane incorporated into the Palaeozoic Sayany-Baikalian belt. Its Neoproterozoic amalgamation history involves early (∼800 Ma) and late Baikalian (600–550 Ma) orogenic phases. Two palaeogeographic elements are identified in the early Baikalian stage — the Gargan microcontinent and the Dunzhugur oceanic arc. They are represented by the Gargan Glyba (Block) and the island-arc ophiolites overthrusting it. The Gargan Glyba is a two-layer platform comprising an Early Precambrian crystalline basement and a Neoproterozoic passive-margin sedimentary cover. The upper part comprises olistostromes deposited in a foreland basin during the early Baikalian orogeny. The Dunzhugur arc ophiolite form klippen fringing the Gargan Glyba, and show a comprehensive oceanic-arc ophiolite succession. The Dunzhugur arc faced the microcontinent, as shown by the occurrence of forearc complexes. The arc–continent Collision followed a pattern similar to Phanerozoic Collisions. When the marginal basin lithosphere had been completely subducted, the microcontinental edge partially underthrust the arc, and the forearc ophiolite overrode it. Continued convergence caused a break of the arc lithosphere resulting in the uplift of the submerged microcontinental margin with the overthrust forearc ophiolites sliding into the foreland basin. Owing to the lithospheric break, a new subduction zone, inclined beneath the Gargan microcontinent, emerged. Initial melts of the newly-formed continental arc are represented by tonalites intruded into the Gargan microcontinent basement and its cover, and into the ophiolite nappe. The tonalite Rb–Sr mineral isochron age is 812±18 Ma, which is similar to a U–Pb zircon age of 785±11 Ma. A period of tonalite magmatism in Meso–Cenozoic orogenic belts is recognized some 1–10 m.y. after the Collision. Accordingly, the Dunzhugur island arc–Gargan microcontinent Collision is conventionally dated at around 800 Ma. It is highly probable that in the early Neoproterozoic, the Gargan continental block was part of the southern (in modern coordinates) margin of the Siberia craton. It is suggested that a chain of Precambrian massifs represents an elongate block separated from Siberia in the late Neoproterozoic. The Tuva-Mongolia Massif is situated in the northwest part of this chain. These events occurred on the NE Neoproterozoic margin of Rodinia, facing the World Ocean.

  • Neoproterozoic (∼800 Ma) orogeny in the Tuva-Mongolia Massif (Siberia): island arc–continent Collision at the northeast Rodinia margin
    Precambrian Research, 2001
    Co-Authors: A Kuzmichev
    Abstract:

    Abstract The Tuva-Mongolia Massif is a composite Precambrian terrane incorporated into the Palaeozoic Sayany-Baikalian belt. Its Neoproterozoic amalgamation history involves early (∼800 Ma) and late Baikalian (600–550 Ma) orogenic phases. Two palaeogeographic elements are identified in the early Baikalian stage — the Gargan microcontinent and the Dunzhugur oceanic arc. They are represented by the Gargan Glyba (Block) and the island-arc ophiolites overthrusting it. The Gargan Glyba is a two-layer platform comprising an Early Precambrian crystalline basement and a Neoproterozoic passive-margin sedimentary cover. The upper part comprises olistostromes deposited in a foreland basin during the early Baikalian orogeny. The Dunzhugur arc ophiolite form klippen fringing the Gargan Glyba, and show a comprehensive oceanic-arc ophiolite succession. The Dunzhugur arc faced the microcontinent, as shown by the occurrence of forearc complexes. The arc–continent Collision followed a pattern similar to Phanerozoic Collisions. When the marginal basin lithosphere had been completely subducted, the microcontinental edge partially underthrust the arc, and the forearc ophiolite overrode it. Continued convergence caused a break of the arc lithosphere resulting in the uplift of the submerged microcontinental margin with the overthrust forearc ophiolites sliding into the foreland basin. Owing to the lithospheric break, a new subduction zone, inclined beneath the Gargan microcontinent, emerged. Initial melts of the newly-formed continental arc are represented by tonalites intruded into the Gargan microcontinent basement and its cover, and into the ophiolite nappe. The tonalite Rb–Sr mineral isochron age is 812±18 Ma, which is similar to a U–Pb zircon age of 785±11 Ma. A period of tonalite magmatism in Meso–Cenozoic orogenic belts is recognized some 1–10 m.y. after the Collision. Accordingly, the Dunzhugur island arc–Gargan microcontinent Collision is conventionally dated at around 800 Ma. It is highly probable that in the early Neoproterozoic, the Gargan continental block was part of the southern (in modern coordinates) margin of the Siberia craton. It is suggested that a chain of Precambrian massifs represents an elongate block separated from Siberia in the late Neoproterozoic. The Tuva-Mongolia Massif is situated in the northwest part of this chain. These events occurred on the NE Neoproterozoic margin of Rodinia, facing the World Ocean.

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  • The diachronous (step-wise) arc–continent Collision in the Urals
    Tectonophysics, 2009
    Co-Authors: V. N. Puchkov
    Abstract:

    Abstract The arc–continent Collision in the Southern Urals was a theme of quite a few publications, dealing with many details of the process, such as deformation and origin of an accretionary prism, exumation of HP/LT metamorphic complexes, and flysch accumulation. Here more attention is drawn to the fact that in the northern areas of the Urals the analogous processes were lagging behind by at least 20 Ma or more compared to the South. The new data discussed in the paper support also the early observation that the metamorphic rocks exhumed at the stage of Collision may preserve isotopic dates for all the earlier processes that took place in the subduction zone. It is suggested that the closure of isotopic systems could be influenced by a cooling action of the subducted slab. It is also pointed out that the diachroneity of Collision may not be necessarily a result of an oblique Collision: an orthogonal Collision may be changed by a scissor-like closure of a triangle oceanic gap left after the first stage of the process.

  • Arc–continent Collision in the Southern Urals
    Earth-Science Reviews, 2006
    Co-Authors: Dennis Brown, Joaquina Alvarez-marrón, V. N. Puchkov, Y. Gorozhanina, Piera Spadea, Richard Herrington, Arne P. Willner, Ralf Hetzel, Christopher Juhlin
    Abstract:

    Abstract The Southern Urals of Russia contain what is arguably one of the best-preserved examples of an arc–continent Collision in any Paleozoic orogen. The arc–continent Collision history recorded in the rocks of the Southern Urals began in the Early Devonian with the onset of intra-oceanic subduction and the formation of the Magnitogorsk Arc and ended with its Collision with the margin of Baltica during the Late Devonian. The Baltica margin consisted of a basement that was composed predominantly of rocks of Archean and Proterozoic age that, by the time of arc–continent Collision, was overlain by Cambrian, Ordovician, Silurian, and Devonian sediments interpreted to have been deposited in rift-related grabens on the continental slope and rise, and on the shallow marine platform. The Magnitogorsk Arc consists of Early to Late Devonian island arc volcanic rocks and overlying volcaniclastic sediments. Arc–continent Collision led to the development of an accretionary complex that includes shallowly and deeply subducted continental margin rocks, ophiolite fragments, and sediments that were deposited in a foreland-basin setting. The geochemistry of the Magnitogorsk Arc volcanic rocks, the structure of the arc–continent Collision accretionary complex and the forearc, the high-pressure rocks beneath and along the suture zone, the mafic and ultramafic ophiolitic material, and the syn-tectonic sediments show that the Paleozoic tectonic processes recorded in the Southern Urals can be favorably compared with those in currently active settings such as the west Pacific.

  • Structure and evolution of the Magnitogorsk forearc basin: Identifying upper crustal processes during Arc-Continent Collision in the southern Urals
    Tectonics, 2001
    Co-Authors: Dennis Brown, Joaquina Alvarez-marrón, A. Pérez-estaún, V. N. Puchkov, Y. Gorozhanina, Puy Ayarza
    Abstract:

    The southern Urals of Russia contain a well-preserved example of a Paleozoic Arc-Continent Collision in which the intraoceanic Magnitogorsk volcanic arc and its forearc basin sediments accreted to the East European Craton during the Devonian. The Magnitogorsk arc records the evolution from incipient intraoceanic subduction to a mature arc, and by comparing its surface geological features with those in active Arc-Continent Collision settings it is possible to identify upper crustal processes that were active in the southern Urals. The arc edifice can be divided into western and eastern volcanic fronts that were active during different stages of arc evolution and for which two distinct phases of forearc basin development can be recognized. The late Lower to Middle Devonian Aktau Formation represents a remnant of the intraoceanic to Collisional forearc basin to the Irendyk volcanic front, whereas the Middle Devonian to Lower Carboniferous Ulutau, Koltubanian, and Zilair Formations were deposited in a suture forearc basin to the east Magnitogorsk volcanic front. It was not until the Late Devonian that these two basins were joined. Structural mapping, combined with reflection seismic profiling, shows these basins to be affected by open, nonlinear, volcanic basement-cored synsedimentary folds. The Karamalytash anticline appears to have the geometry of a growth fold that formed during deposition of sediments in the suture forearc basin. The forearc region is affected by minor thrusting that involves the volcanic basement, although it is not clear if these thrusts reactivate preexisting trench-parallel faults. Synsedimentary deformation, slumping, and olistostrome development were common throughout the suture forearc basin history but were especially widespread during the Late Devonian, when the full thickness of the continental crust is interpreted as having arrived at the subduction zone.

  • Accretionary complex structure and kinematics during Paleozoic arc–continent Collision in the southern Urals
    Tectonophysics, 2000
    Co-Authors: Joaquina Alvarez-marrón, Dennis Brown, A. Pérez-estaún, V. N. Puchkov, Y. Gorozhanina
    Abstract:

    Abstract The southern Urals contain a well-preserved accretionary complex that has overthrust the continental margin during arc–continent Collision between the East European Craton (EEC) and the Magnitogorsk island arc in the Late Devonian. Within the accretionary complex, we study three tectonic units that differ in deformation style, and each provides a unique geodynamic implication. The Zilair Nappe, the largest and best exposed unit, consists of 5–6 km of synCollisional, arc-derived Upper Devonian to Lower Carboniferous polymictic and graywacke turbidites that were deposited across the continental margin and incorporated by frontal accretion into the accretionary complex. The Zilair Nappe is a bivergent thrust imbricate where the west-vergent thrusts dominate and have associated kilometer-scale ramp anticlines with well developed east-dipping axial planar cleavage. Along its eastern contact, however, the cleavage fans until it dips moderately westward and the folds are east-vergent. Following its emplacement, west-vergent, basement-involved thrusting that breached the whole accretionary complex imbricated the Zilair Nappe. The Timirovo Duplex is structurally beneath the Zilair Nappe, and outcrops for several tens of kilometers along its northwestern margin. The duplex forms a west-vergent thrust stack composed of a highly deformed and sheared Lower and Middle Devonian reef carbonates of the former EEC margin platform. These rocks were shallowly underplated at the base of the accretionary complex during emplacement over the margin. The Suvanyak Complex outcrops along the eastern contact of the Zilair Nappe, and consists of polydeformed greenschist facies metasediments of the former EEC slope that were offscraped, underplated and incorporated at the rear of the accretionary complex.