Subduction zone recycling processes and the rock record of crustal suture zonesThis article is one of a series of papers published in this Special Issue on the theme Lithoprobe — parameters, processes, and the evolution of a continent.

2010 ◽  
Vol 47 (5) ◽  
pp. 633-654 ◽  
Author(s):  
David W. Scholl ◽  
Roland von Huene
Keyword(s):  
Subduction Zones ◽  
Crustal Material ◽  
Basement Rock ◽  
Special Issue ◽  
Linear Rate ◽  
Tectonic Processes ◽  
Crustal Thinning ◽  
Rock Record ◽  
Seaward Edge ◽  
Subduction Erosion

Offshore observations at modern ocean-margin subduction zones (OMSZs) reveal that bodies of accreted material are commonly volumetrically small or missing, that crustal thinning and subsidence (3–5 km) has occurred, and that most trench axes lie close (5–30 km) to the seaward tapering edge of coastal basement rock. Onshore mapping commonly documents missing or only narrow terranes of former forearc rock and the inboard migration of the arc magmatic front. These observations are evidence that subduction is accompanied by the removal of sediment and crustal material from the submerged forearc by the kindred tectonic processes, respectively, of sediment subduction and subduction erosion. Subduction erosion truncates the margin (migrates the trench inboard) at ∼2.5 km/Ma. Onshore observations at ancient crust-suturing subduction zones (CSSZs) imply that collisional suturing is accompanied by sediment subduction and truncation of both upper and lower plates. During a protracted period of suturing (20–50 million years), a 100–200 km wide (or wider) band of the seaward edge of each plate can be removed subductively. Truncation of the upper plate is effected by subduction erosion, and that of the lower plate by the necking and break-off of its subducted edge. The average linear rate of crustal loss for each plate is estimated at ∼1.5 km/Ma, or ∼3 km/Ma combined. Because significant crustal loss occurs before and during tectonic fusing of colliding crustal blocks, structures and rock bodies that might be expected to record a former OMSZ and the formation of a CSSZ may be absent, unimpressively small, or preserved only as exhumed masses of once deeply subducted material.

scholarly journals Up the down escalator: the exhumation of (ultra)-high pressure terranes during on-going subduction

2012 ◽  
Vol 4 (1) ◽  
pp. 745-781 ◽  
Author(s):  
C. J. Warren
Keyword(s):  
High Pressure ◽  
Subduction Zone ◽  
Continental Crust ◽  
Subduction Zones ◽  
Crustal Material ◽  
Time And Space ◽  
Ultra High Pressure ◽  
Tectonic Environment ◽  
Tectonic Style ◽  
Weak Material

Abstract. The exhumation of high and ultra-high pressure rocks is ubiquitous in Phanerozoic orogens created during continental collisions, and is common in many ocean-ocean and ocean-continent subduction zone environments. Three different tectonic environments have previously been reported, which exhume deeply buried material by different mechanisms and at different rates. However it is becoming increasingly clear that no single mechanism dominates in any particular tectonic environment, and the mechanism may change in time and space within the same subduction zone. In order for buoyant continental crust to subduct, it must remain attached to a stronger and denser substrate, but in order to exhume, it must detach (and therefore at least locally weaken) and be initially buoyant. Denser oceanic crust subducts more readily than more buoyant continental crust but exhumation must be assisted by entrainment within more buoyant and weak material such as serpentinite or driven by the exhumation of structurally lower continental crustal material. Weakening mechanisms responsible for the detachment of crust at depth include strain, hydration, melting, grain size reduction and the development of foliation. These may act locally or may act on the bulk of the subducted material. Metamorphic reactions, metastability and the composition of the subducted crust all affect buoyancy and overall strength. Subduction zones change in style both in time and space, and exhumation mechanisms change to reflect the tectonic style and overall force regime within the subduction zone. Exhumation events may be transient and occur only once in a particular subduction zone or orogen, or may be more continuous or occur multiple times.

Seismic imaging evidence that forearc underplating built the accretionary rock record of coastal North and South America

2019 ◽  
Vol 158 (1) ◽  
pp. 104-117 ◽  
Author(s):  
David W. Scholl
Keyword(s):  
South America ◽  
Subduction Zones ◽  
Seismic Imaging ◽  
Southern Chile ◽  
Late Palaeozoic ◽  
Aleutian Arc ◽  
Seaward Edge ◽  
Metamorphic Facies ◽  
North And South America ◽  
North And South

AbstractThe submerged forearcs of Pacific subduction zones of North and South America are underlain by a coastally exposed basement of late Palaeozoic to early Tertiary age. Basement is either an igneous massif of an accreted intra-oceanic arc or oceanic plateau (e.g. Cascadia(?), Colombia), an in situ formed arc massif (e.g. Aleutian Arc) or an exhumed accretionary complex of low and high P/T metamorphic facies of late Palaeozoic (e.g. southern Chile, Patagonia) and Mesozoic age (e.g. Alaska). Seismic studies at Pacific forearcs image frontal prisms of trench sediment accreted to the seaward edge of forearc basement. Frontal prisms tend to be narrow (10–40 km), weakly consolidated and volumetrically small (∼35–40 km3/km of trench). In contrast, deep seismic imaging of submerged forearcs commonly reveals large volumes (∼2000 km3/km of trench) of underplated material accreted at subsurface depths of ∼10–30 km to the base of forearc basement. Underplates have been imaged below the southern Chile, Ecuador–Colombia, north Cascade, Alaska, and possibly the eastern Aleutian forearcs. Deep underplates have also been observed below the Japan and New Zealand forearcs. Seismic imaging of northern and eastern Pacific forearcs supports the conclusion drawn from field and laboratory studies that exposed low and high P/T accretionary complexes accumulated in the subsurface at depths of 10–30 km. It seems significant that imaged underplated bodies are characteristic of modern well-sedimented subduction zones. It also seems likely that large Pacific-rim underplates store a significant fraction of sediment subducted in Cenozoic time.

scholarly journals THE WAVE GEODYNAMIC IMPACT OF TECTONIC PROCESSES ON THE AMURIAN PLATE

2021 ◽  
Vol 40 (4) ◽  
pp. 72-86
Author(s):  
V.G. Bykov ◽  
◽  
T.V. Merkulova ◽  
Keyword(s):  
Subduction Zones ◽  
Western Pacific ◽  
Relative Contribution ◽  
Tectonic Processes ◽  
Time Period ◽  
Amurian Plate ◽  
Recent Geodynamics ◽  
Different Depths ◽  
The Western Pacific ◽  
Migration Of Earthquakes

The analysis of data on the migration of earthquakes and slow deformations from the Indo-Eurasian collision and the Western Pacific subduction zones is given, and the wave “geodynamic impact” of these tectonic processes on the Amurian plate and surrounding structures is shown. The interaction and a relative contribution of collision and subduction to the recent geodynamics of the Amurian plate are discussed. A scheme is constructed showing localizations of the slow strain wave manifestation in the areas of central and eastern Asia. The calculations are performed aimed at revealing a transverse migration of earthquakes (M ≥ 6.5) directed from the Japan and the Kuril-Kamchatka trenches toward the Asian continent during the time period from 1960 to 2015. The migration of earthquakes along the profile crossing Hokkaido Island occurs at velocities of 15 and 23 km/yr, whereas the migration velocity from the Kuril-Kamchatka Trench via Sakhalin Island is evaluated from 20 to 40 km/yr at different depths. We focus on an insufficient study of the influence of the Western Pacific subduction on the formation of the deformation field in continental Asia.

scholarly journals Supplemental Material: Subduction erosion and crustal material recycling indicated by adakites in central Tibet

2021 ◽  
Author(s):  
Zong-Yong Yang ◽  
QIANG WANG ◽  
et al.
Keyword(s):  
Analytical Methods ◽  
Crustal Material ◽  
Material Recycling ◽  
Subduction Erosion ◽  
Central Tibet

Supplemental figures, analytical methods and results, and data and results tables.<br>

scholarly journals Supplemental Material: Crustal material recycling induced by subduction erosion and subduction-channel exhumation: A case study of central Tibet (western China) based on P-T-t paths of the eclogite-bearing Baqing metamorphic complex

2020 ◽  
Author(s):  
Xin Jin ◽  
Yu-Xiu Zhang ◽  
Kai-Jun Zhang ◽  
et al.
Keyword(s):  
Western China ◽  
Metamorphic Rocks ◽  
Crustal Material ◽  
Metamorphic Complex ◽  
Subduction Channel ◽  
Material Recycling ◽  
Subduction Erosion ◽  
Mineral Compositions ◽  
Central Tibet

Compositional mapping images of one garnet, Triassic paleo-geographic facies of Qiangtang, summarized published Paleozoic and Proterozoic ages in Tibetan Plateau and Himalaya, mineral compositions, and chronology data of the Baqing metamorphic rocks.

Evidence for seamount accretion to a peri-Laurentian arc during closure of Iapetus 1This article is one of a series of papers published in CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology.2 Geological Survey of Canada Contribution 20100465.

2012 ◽  
Vol 49 (1) ◽  
pp. 147-165 ◽  
Author(s):  
A. Zagorevski ◽  
V. McNicoll
Keyword(s):  
Accretionary Prism ◽  
Special Issue ◽  
Volcanic Arc ◽  
Bay Area ◽  
Mylonite Zone ◽  
Iapetus Ocean ◽  
Subduction Erosion ◽  
Area Preserve ◽  
Laurentian Margin ◽  
Accretionary Prisms

The Red Indian Line is the fundamental Iapetus suture zone in the Newfoundland Appalchians along which the main tract of the Iapetus Ocean was consumed. Despite being the site of the closure of a wide ocean, few vestiges of the Iapetus plate have been accreted along Red Indian Line. Ordovician rocks in the Notre Dame Bay area preserve the only evidence for accretion of a seamount in Newfoundland. The seamount is characterized by alkali basalt and hypabyssal rocks that are juxtaposed with Darriwilian peri-Laurentian volcanic arc rocks (466 ± 4 and 467 ± 4 Ma) along a major mylonite zone. The mylonite zone lacks sedimentary rocks suggesting that the seamount was accreted to the arc along a sediment-starved interface and that significant subduction erosion took place along the Laurentian margin. Identification of subduction erosion indicates that an accretionary prism did not exist outboard of Laurentia in Newfoundland, in contrast to the well developed accretionary prisms of the Caledonides.

scholarly journals Boron Cycling in Subduction Zones

Elements ◽  
2017 ◽  
Vol 13 (4) ◽  
pp. 237-242 ◽  
Author(s):  
Martin R. Palmer
Keyword(s):  
Isotopic Composition ◽  
Subduction Zones ◽  
Accretionary Prism ◽  
Crustal Material ◽  
Seawater Chemistry ◽  
Ocean Island ◽  
Ocean Island Basalts ◽  
Ideal Tracer

Subduction zones are geologically dramatic features, with much of the drama being driven by the movement of water. The “light and lively” nature of boron, coupled with its wide variations in isotopic composition shown by the different geo-players in this drama, make it an ideal tracer for the role and movement of water during subduction. The utility of boron ranges from monitoring how the fluids that are expelled from the accretionary prism influence seawater chemistry, to the subduction of crustal material deep into the mantle and its later recycling in ocean island basalts.

Ali Mehmet Celâl Şengör: A geologist who unravels the histories of continents and oceans

2019 ◽  
Vol 56 (12) ◽  
pp. v-viii
Author(s):  
Ali Polat ◽  
John F. Dewey
Keyword(s):  
Earth Sciences ◽  
Canadian Journal ◽  
Plate Tectonics ◽  
Research Articles ◽  
Special Issue ◽  
Tectonic Processes ◽  
History Of Geology ◽  
History Of ◽  
Rocky Planets

This second issue of the Canadian Journal of Earth Sciences special issue dedicated to Ali Mehmet Celâl Şengör for his outstanding contributions to plate tectonics and history of geology includes 11 research articles. These articles have diverse subject matters dealing with tectonic processes in California, Africa, Asia, Iceland, Europe, Canada, and rocky planets. The summaries and main conclusions of these articles are presented here.

Subduction erosion and crustal material recycling indicated by adakites in central Tibet

Geology ◽  
2021 ◽  
Author(s):  
Zong-Yong Yang ◽  
Qiang Wang ◽  
Lu-Lu Hao ◽  
Derek A. Wyman ◽  
Lin Ma ◽  
...  
Keyword(s):  
Crustal Material ◽  
Convergent Margins ◽  
Nd Isotopes ◽  
Magmatic Arc ◽  
Material Recycling ◽  
Intrusive Rocks ◽  
Subducted Oceanic Crust ◽  
Subduction Erosion ◽  
Central Tibet ◽  
Qiangtang Terrane

Subduction erosion is important for crustal material recycling and is widespread in modern active convergent margins. However, such a process is rarely identified in fossil convergent systems, which casts doubt on the importance of subduction erosion through the geological record. We report on ca. 155 Ma Kangqiong (pluton) intrusive rocks of a Mesozoic magmatic arc in the southern Qiangtang terrane, central Tibet. These rocks mainly consist of trondhjemites and tonalites and are similar to slab-derived adakites with mantle-like zircon oxygen isotope compositions (δ18O = 5.2‰–5.6‰), they display more evolved Sr-Nd isotopes and higher Th/La relative to mid-oceanic ridge basalts from the Bangong-Nujiang suture, and they contain abundant amphibole and biotite. These characteristics indicate magma generation via H2O-fluxed melting of eroded forearc crust debris with subducted oceanic crust at 1.5–2.5 GPa and 700–800 °C. In addition, the intrusions are exposed &lt;20 km north of the Bangong-Nujiang suture. Given the formation of adakites, narrow arc-suture distance, migration of the Jurassic frontal arc toward the continent interior, and other independent geological archives, we suggest that the hydrated forearc crust materials were removed from the overlying plate and carried into the mantle by subduction erosion. Our study provides the first direct magmatic evidence for a subduction erosion process in pre-Cenozoic convergent systems, which confirms an important role for such processes in subduction-zone material recycling.

scholarly journals Occurrences of sulphide minerals in the Stak and Tso Morari eclogites: Implications for the behaviour of sulphur and chalcophile elements in subduction zones

2008 ◽  
Vol 5 (7) ◽  
pp. 118
Author(s):  
Nicolas Riel ◽  
Keiko Hattori ◽  
Stephane Guillot ◽  
Mohamad Latif ◽  
Allah B Kausar
Keyword(s):  
Subduction Zones ◽  
Special Issue ◽  
Sulphide Minerals ◽  
Chalcophile Elements ◽  
Tso Morari

DOI = 10.3126/hjs.v5i7.1307 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.118

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