scholarly journals Geohistory of Tso-Morari Crystalline, Eastern Ladakh, India: a plausible model for ultra-high pressure rocks in the Himalaya

1970 ◽  
Vol 5 (7) ◽  
pp. 139-140 ◽  
Author(s):  
Ram S Sharma
Keyword(s):  
High Pressure ◽  
Special Issue ◽  
Ultra High Pressure ◽  
Plausible Model ◽  
The Himalaya ◽  
Tso Morari

DOI = 10.3126/hjs.v5i7.1321 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.139-140

scholarly journals The metamorphism of the Tso Morari ultra-high pressure nappe of the Ladakh Himalaya

1970 ◽  
Vol 5 (7) ◽  
pp. 157-158
Author(s):  
Albrecht Steck ◽  
Jean-Luc Epard
Keyword(s):  
High Pressure ◽  
Special Issue ◽  
Ultra High Pressure ◽  
Ladakh Himalaya ◽  
Tso Morari

DOI = 10.3126/hjs.v5i7.1336 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.157-8

scholarly journals The Tectonics of the Tso Morari Ultra High Pressure Nappe in Ladakh, NW Indian Himalaya

1970 ◽  
Vol 5 (7) ◽  
pp. 159-160
Author(s):  
Albrecht Steck ◽  
Jean-Luc Epard
Keyword(s):  
High Pressure ◽  
Special Issue ◽  
Indian Himalaya ◽  
Ultra High Pressure ◽  
Tso Morari

DOI = 10.3126/hjs.v5i7.1337 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.159-160

U–Pb zircon geochronology of eclogites from the Scandian Orogen, northern Western Gneiss Region, Norway: 14–20 million years between eclogite crystallization and return to amphibolite-facies conditionsThis article is one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh.

2011 ◽  
Vol 48 (2) ◽  
pp. 441-472 ◽  
Author(s):  
Thomas E. Krogh ◽  
Sandra L. Kamo ◽  
Peter Robinson ◽  
Michael P. Terry ◽  
Kim Kwok
Keyword(s):  
High Pressure ◽  
Continental Collision ◽  
Amphibolite Facies ◽  
Granitic Pegmatite ◽  
Zircon Geochronology ◽  
Plate Tectonic ◽  
Special Issue ◽  
Western Gneiss Region ◽  
Garnet Pyroxenite ◽  
Ultra High Pressure

Reconstructing tectonic histories involving continental collision, subduction, and exhumation at plate-tectonic rates of ∼1 cm/year, requires precise U–Pb zircon geochronology. The Western Gneiss Region has exceptional exposures of high-pressure (HP) and ultra-high-pressure (UHP) rocks. The strategy adopted here involved sampling eclogite and associated late unstrained pegmatites to acquire the time of eclogite crystallization and subsequent exhumation, respectively. The oldest eclogite sampled is 415 ± 1 Ma from layered, probably UHP eclogite at Tevik, Averøya, also with a garnet–hornblende assemblage at 410 ± 1 Ma. The Flem Gabbro eclogite margin, with implied UHP conditions, is 410 ± 2 Ma. Hornblende eclogite at Seth, Lepsøya, never at UHP, is 412 ± 2 Ma. These compare to Devonian ages of 401 ± 1 Ma for overgrowths on Proterozoic baddeleyite in Selnes Gabbro, 402 ± 2 Ma for coesite eclogite at Hareidlandet, 405–400 Ma for coesite eclogite at Flatraket, and 405 ± 2 Ma for near-UHP eclogite at Hjelmelandsdalen. The 415 Ma eclogite at Tevik compares to granitic pegmatite in the same outcrop at 395.2 ± 1.3 Ma and to pegmatite in eclogite at Aspøya at 395.3 ± 2 Ma. The 410 Ma age at Flem compares to nearby pegmatite in eclogite at 396 ± 4 Ma. Collectively, these results imply 14–20 million years between deep eclogite crystallization at ∼130 km and return to amphibolite-facies conditions at ∼30 km, with crystallization of locally derived granitoid melts. Nearby garnet-pyroxenite records older ages (∼430) and greater depths (∼200 km), but on similar exhumation paths at ∼0.4–0.7 cm/year.

scholarly journals Trans-lithospheric diapirism explains the presence of ultra-high pressure rocks in the European Variscides

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Petra Maierová ◽  
Karel Schulmann ◽  
Pavla Štípská ◽  
Taras Gerya ◽  
Ondrej Lexa
Keyword(s):  
High Pressure ◽  
Numerical Models ◽  
Classical Concept ◽  
Plate Interface ◽  
Ultra High Pressure ◽  
Common Process ◽  
Mountain Belts ◽  
Collisional Orogens ◽  
Rock Association ◽  
European Variscides

AbstractThe classical concept of collisional orogens suggests that mountain belts form as a crustal wedge between the downgoing and overriding plates. However, this orogenic style is not compatible with the presence of (ultra-)high pressure crustal and mantle rocks far from the plate interface in the Bohemian Massif of Central Europe. Here we use a comparison between geological observations and thermo-mechanical numerical models to explain their formation. We suggest that continental crust was first deeply subducted, then flowed laterally underneath the lithosphere and eventually rose in the form of large partially molten trans-lithospheric diapirs. We further show that trans-lithospheric diapirism produces a specific rock association of (ultra-)high pressure crustal and mantle rocks and ultra-potassic magmas that alternates with the less metamorphosed rocks of the upper plate. Similar rock associations have been described in other convergent zones, both modern and ancient. We speculate that trans-lithospheric diapirism could be a common process.

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