Eclogite-facies shear zones—deep crustal reflectors?
نویسندگان
چکیده
منابع مشابه
Eclogite-facies metamorphism preserved in tectonic blocks from a lower crustal shear zone, central Transantarctic Mountains, Antarctica
In the Geologists and Miller Ranges of the central Transantarctic Mountains, mafic and ultramalic tectonic blocks occur in an Early Cambrian amphiboliteto granulite-facies lower crustal transpressional shear zone. Mafic blocks consist of garnet + clinopyroxene symplectite + hornblende + plagioclase + quartz + ilmenite f orthopyroxene f biotite;mineral compositions in these blocks generally refl...
متن کاملEclogite-facies fluid infiltration: constraints from dO zoning in garnet
In situ analysis reveals that eclogite-facies garnets are zoned in dO with lower values in the core and rims that are *1.5 to 2.5 % higher. This pattern is present in 9 out of 12 garnets analyzed by SIMS from four orogenic eclogite terranes, and correlates with an increase in the mole fraction of pyrope and Mg/Fe ratio from core to rim, indicating prograde garnet growth. At the maximum temperat...
متن کاملWhole-rock Geochemistry and Metamorphism of Blueschist/eclogite-facies Mafic Rocks on Syros, Cyclades, Greece
The island of Syros consists largely of possibly-repeated sequences of glaucophane-bearing calcareous schists, mafic schists, dolomite marbles, and calcite marbles containing abundant aragonite pseudomorphs (Dixon, 1969; Hecht, 1984). Several discrete, fault-bounded packages of blueschist/eclogite-facies mafic rocks with minor serpentinite are also found on the island. Although the mafic rocks ...
متن کاملLate Miocene–Pliocene eclogite facies metamorphism, D’Entrecasteaux Islands, SE Papua New Guinea
The D’Entrecasteaux Islands of south-eastern Papua New Guinea are active metamorphic core complexes that formed within a region where the plate tectonic regime has transitioned from subduction to rifting. While rapid, post 4 Myr exhumation and cooling of amphibolite and greenschist facies rocks that constitute the footwall of the crustal scale detachment fault system have been previously docume...
متن کاملEclogitization of lower crustal granulites by fluid migration through shear zones
The granulite facies assemblages of the anorthositic rocks of the Bergen Arcs (stable at 800 -900°C and 10 kbar) have been transformed to eclogite facies assemblages (stable at 700 -750°C and 16-19 kbar) in the vicinity of Caledonian shear zones. This section of the root zone of the Caledonian mountain chain reveals a deep polymetamorphic crust where Precambrian granulites (mean density 3.02 g ...
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ژورنال
عنوان ژورنال: Tectonophysics
سال: 1994
ISSN: 0040-1951
DOI: 10.1016/0040-1951(94)90100-7