Maximum Scale of Continental Crust Sliver Driven By Subducting Oceanic Slab: South Island of New Zealand and Ultra High Pressure Metamorphism at Dabie, China

2001 ◽  
Vol 44 (6) ◽  
pp. 741-747
Author(s):  
Yao-Lin SHI ◽  
Tao-Yuan FAN
Keyword(s):  
High Pressure ◽  
New Zealand ◽  
Continental Crust ◽  
High Pressure Metamorphism ◽  
Ultra High Pressure ◽  
Oceanic Slab

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.

Ultra-high-pressure metamorphism in felsic rocks: the garnet-phengite gneisses and quarzites from the Lanterman Range, Antarctica

2003 ◽  
Vol 15 (3) ◽  
pp. 513-525 ◽  
Author(s):  
Rosaria Palmeri ◽  
Barbara Ghiribelli ◽  
Franco Talarico ◽  
Carlo Alberto Ricci
Keyword(s):  
High Pressure ◽  
High Pressure Metamorphism ◽  
Ultra High Pressure ◽  
Felsic Rocks

(Ultra-) High-pressure metamorphism and orogenesis: An Alpine perspective

2010 ◽  
Vol 18 (1) ◽  
pp. 147-166 ◽  
Author(s):  
Marco Beltrando ◽  
Roberto Compagnoni ◽  
Bruno Lombardo
Keyword(s):  
High Pressure ◽  
High Pressure Metamorphism ◽  
Ultra High Pressure

scholarly journals The role of buoyancy in the fate of ultra-high-pressure eclogite

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Timothy Chapman ◽  
Geoffrey L. Clarke ◽  
Nathan R. Daczko
Keyword(s):  
High Pressure ◽  
Continental Crust ◽  
Upper Mantle ◽  
Crustal Rocks ◽  
Ultra High Pressure ◽  
Rock Types ◽  
Mineral Assemblages ◽  
Facies Metamorphism ◽  
Point Of No Return

AbstractEclogite facies metamorphism of the lithosphere forms dense mineral assemblages at high- (1.6–2.4 GPa) to ultra-high-pressure (>2.4–12 GPa: UHP) conditions that drive slab-pull forces during its subduction to lower mantle conditions. The relative densities of mantle and lithospheric components places theoretical limits for the re-exposure, and peak conditions expected, of subducted lithosphere. Exposed eclogite terranes dominated by rock denser than the upper mantle are problematic, as are interpretations of UHP conditions in buoyant rock types. Their subduction and exposure require processes that overcame predicted buoyancy forces. Phase equilibria modelling indicates that depths of 50–60 km (P = 1.4–1.8 GPa) and 85–160 km (P = 2.6–5 GPa) present thresholds for pull force in end-member oceanic and continental lithosphere, respectively. The point of no-return for subducted silicic crustal rocks is between 160 and 260 km (P = 5.5–9 GPa), limiting the likelihood of stishovite–wadeite–K-hollandite-bearing assemblages being preserved in equilibrated assemblages. The subduction of buoyant continental crust requires its anchoring to denser mafic and ultramafic lithosphere in ratios below 1:3 for the continental crust to reach depths of UHP conditions (85–160 km), and above 2:3 for it to reach extreme depths (>160 km). The buoyant escape of continental crust following its detachment from an anchored situation could carry minor proportions of other rocks that are denser than the upper mantle. However, instances of rocks returned from well-beyond these limits require exceptional exhumation dynamics, plausibly coupled with the effects of incomplete metamorphism to retain less dense low-P phases.

Solidus of carbonated phlogopite eclogite at 3-6 GPa: Implications for mantle metasomatism and ultra-high pressure metamorphism

2021 ◽  
Author(s):  
Anton Shatskiy ◽  
Altyna Bekhtenova ◽  
Ivan V. Podborodnikov ◽  
Anton V. Arefiev ◽  
Yulia G. Vinogradova ◽  
...  
Keyword(s):  
High Pressure ◽  
Mantle Metasomatism ◽  
High Pressure Metamorphism ◽  
Ultra High Pressure

A Servohydraulically-controlled Deformation Apparatus for Rock Deformation under Conditions of Ultra-high Pressure Metamorphism

1998 ◽  
Vol 152 (3) ◽  
pp. 579-606 ◽  
Author(s):  
E. Rybacki ◽  
J. Renner ◽  
K. Konrad ◽  
W. Harbott ◽  
F. Rummel ◽  
...  
Keyword(s):  
High Pressure ◽  
Rock Deformation ◽  
High Pressure Metamorphism ◽  
Ultra High Pressure
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