Geodynamic controls on magmatic arc migration and quiescence

Gianni, Guido M.; Luján, Sofía Pérez

doi:10.1016/j.earscirev.2021.103676

Cited by 42 publications

(21 citation statements)

References 342 publications

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“…In the CVA, the present-day clockwise rotation of the Oregon and Washington blocks and the counterclockwise displacement of the volcanic front since the Miocene have been ascribed to differential along strike rollback of the Juan de Fuca slab [27][28][29][30] . However, assuming that the magmatic source follows the rollbacking slab 1,[4][5][6] , this model requires some unconstrained degree of decoupling between rollback and arc migration 28 . In the North Cascades, the increase in the rate of arc migration towards the southwest since ~4 Ma (Refs.…”

Section: Discussionmentioning

confidence: 99%

“…Volcanic arcs at convergent plate margins are located above the zone of dehydration of a subducting oceanic plate, leading to partial melting of mantle rocks at ~100 km depth, depending on the mean slab dip angle, convergence velocity and thermal structure of the slab and mantle wedge [1][2][3][4] . Assuming a vertical magma transfer from the mantle melting zone to the upper crust in subduction settings 4 , slab rollback and trench retreat lead to arc migration towards the subducting plate, whereas slab flattening and trench advancement force arc magmatism towards the continent 3,5,6 . In addition to processes that change the depth and position of the mantle melting zone, lithospheric brittle-ductile shear zones serve as fundamental conduits to drive the magma upwelling to the surface, thereby affecting the location of the volcanic arc with respect to the magma source in the mantle and crust [7][8][9][10] .…”

Section: Introductionmentioning

confidence: 99%

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Climatic control on the location of continental volcanic arcs

Müller

Sternai

Sue

et al. 2022

Preprint

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Orogens and volcanic arcs at continental plate margins are primary surface expressions of convergent plate tectonics. Although it is established that climate affects the shape, size, and architecture of orogens via orographic erosion gradients, the crustal upwelling of magmas and location of volcanic arcs have been considered insensitive to erosion. However, available data reveal westward migration of late-Cenozoic volcanic activity in the Southern Andes and Cascade Range where orography drives an eastward migration of the topographic water divide by increased precipitation and erosion along west-facing slopes. Here we use thermomechanical numerical modeling to show that orographic erosion and leeward topographic shift may entail asymmetric crustal structures, driving magma upwelling toward the region of enhanced erosion. Considering the different tectonic histories between the Southern Andes and the Cascade Range, the orographic erosion gradient is a plausible shared causal mechanism behind the late-Cenozoic westward migration of the regional volcanic arcs.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Climatic control on the location of continental volcanic arcs

Müller

Sternai

Sue

et al. 2022

Preprint

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“…The rocks were enriched with both LREE and HREE, HFSE. The Sr/Y < 25, (Th/La) PM < 1, had elevated concentrations of Ta, Th, Yb, which may indicate the involvement of astenospheric melts [26,[72][73][74][75]. According to 147 Sm/ 144 Nd systematics, the fourth group was close to the second group, having island-arc geochemical characteristics.…”

Section: Constraints On Mantle Sourcementioning

confidence: 90%

“…Geodynamic processes could be associated with the rollback of the subducting oceanic lithosphere, slab breakoff, upwelling asthenosphere, and decompression melting. It would produce E-MORB and OIB-like magma with high 87 Sr/ 86 Sr and low 143 Nd/ 144 Nd values [73][74][75]. Further, these processes could lead to an extension of the Dunzhugur island arc that can be attributed to intra-arc rifting and subsequent formation the Shishkhid back-arc basin [4].…”

Section: Constraints On Mantle Sourcementioning

confidence: 99%

Nd-Sr Isotopic Study of Magmatic Rocks and 40Ar/39Ar Dating of the Mafic Dike of the Proterozoic Ulan-Sar’dag Ophiolite Mélange (Southern Siberia, East Sayan, Middle Belt, Russia)

et al. 2022

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We report the first radiogenic Nd-Sr isotope data in the magmatic rocks island-arc ophiolite assemblage from the middle branch of the East Sayan ophiolite complexes to better constrain geodynamic processes in this segment of the CAOB in southern central Siberia. The magmatic rocks belong to the following geochemical types: (1) Ensimatic island-arc boninites; (2) island-arc assemblage; (3) enriched basalts of mid-ocean ridges; and (4) oceanic island-like basalts. The boninites have a positive value εNd (T), which is generated from a depleted mantle source (N-MORB). The island-arc assemblage has negative or slightly positive εNd (T) and was formed from an enriched mantle source due to the subduction of terrigenous rocks. The source of the terrigenous material was most likely the rocks of the Archean TTG (Trondhjemite Tonalite Granodiorite) complex of the Gargan block. Isotopic ratios for E-MOR and OIB-like basalts are characterized by positive or slightly negative values of εNd (T). The mafic dike, which crosscut ophiolite rocks, corresponds to OIB-like basalts. The values of εNd (T), measured 87Sr/86Sr and I (Sr), in the mafic dike correspond to the EM I mantle source. The E-MOR and OIB-like basalts appear to be formed in late-stage asthenospheric mantle melting via the decompression melting processes. The obtained isotope geochemical data for the E-MOR and OIB-like basalts probably indicate the mixing of island-arc melts with asthenospheric melts. We undertook 40Ar/39Ar dating of the mafic dike, which crosscut the ophiolite unit. The mafic dike has a whole-rock 40Ar/39Ar weighted mean plateau age of 799 ± 11 Ma. The dating constrains the minimum age of the ophiolite and island-arc magmatism in the region.

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“…When the accretionary orogen is under an advancing and retreating mode, it may lead to compressional and extensional tectonics, respectively. Compressional deformation affects the upper plate, leading to crustal thickening and eventual inland arc magmatism migration (Gianni and Luján, 2021). Alternatively, extensional processes may lead to outward trench and arc migration with respect to the overriding plate (e.g., Schellart, 2008).…”

Section: Introductionmentioning

confidence: 99%

Forearc tectonics and volcanism during the Devonian–Carboniferous evolution of the North Patagonian segment, southern Chile (41,3°S)

Palape

Quezada²,

Bastías³

et al. 2022

Front. Earth Sci.

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Late Paleozoic to early Mesozoic subduction complexes formed during the evolution of southwestern Gondwana and extensively crop out along the Chilean continental margin. Recent findings in northern Patagonia (40°–43°S) revealed that accretionary processes were active since the Devonian when enhanced lithosphere stretching in the forearc led to the formation of Chaitenia island arc. The extension in the crust consecutively developed a backarc basin, which culminated during a compressive episode that re-amalgamated the Chaitenia island arc with the margin. This episode produced intermediate grade metamorphism in the sedimentary rocks that were formed throughout the extension. To constrain the tectonic evolution of these processes, we combined petrology, structural analysis, whole-rock geochemical, and whole-rock isotopic tracing (Sr-Nd-Pb) data along with thermodynamic modelling. Two petro-tectonic domains are here defined. The Western Coastal Range Domain is composed of Carboniferous to Permian metapsammopelitic rocks, which are mainly schists with a metasedimentary Carboniferous protolith exhibiting a penetrative northeast to southwest dipping main foliation associated with basal accretion. The Eastern Coastal Range Domain is comprised by garnet micaschists, metabasalts, metarhyolites, and metasandstones. This unit is folded by three ductile structures: The first is related to rootless isoclinal folds, the second is associated with kilometric scale west-verging tight folds, and the third is associated with west-verging cylindrical folds. The volcanic rocks of this domain are comprised by middle Devonian alkaline metarhyolites and metabasalts with enriched-MORB and normal-MORB affinities. Trace element composition suggests that the metabasalts formed through shallow melting in an extensional setting over a supra-subduction zone. Nd and Pb isotope data point to a mantle source change for the basaltic melts from an EM1-like to a DM-like and are interpreted to reflect the embryonic to mature evolution of the early Devonian to Carboniferous backarc system. The calculated P–T evolution of the garnet micaschists follows: 1) a clockwise IP–IT prograde Barrovian path, 2) an isobaric thermal increase at ∼7 kbar and 540°C, and 3) an adiabatic decompression. Finally, after the metamorphism, these rocks were uplifted by thrusting processes that probably occurred during the late Permian.

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Geodynamic controls on magmatic arc migration and quiescence

Cited by 42 publications

References 342 publications

Climatic control on the location of continental volcanic arcs

Climatic control on the location of continental volcanic arcs

Nd-Sr Isotopic Study of Magmatic Rocks and 40Ar/39Ar Dating of the Mafic Dike of the Proterozoic Ulan-Sar’dag Ophiolite Mélange (Southern Siberia, East Sayan, Middle Belt, Russia)

Forearc tectonics and volcanism during the Devonian–Carboniferous evolution of the North Patagonian segment, southern Chile (41,3°S)

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