نتایج جستجو برای: blueschist facies
تعداد نتایج: 5608 فیلتر نتایج به سال:
The western Tianshan high-pressure/low-temperature orogenic belt in NW China contains eclogite-facies metavolcanic rocks and omphacite-bearing blueschists. Previous Sm-Nd (omphacite, garnet, glaucophane, whole rock) and Ar/Ar (crossite) dating of eclogite-facies rocks has suggested an age of ca. 345 Ma as the best approximation for the timing of peak metamorphic conditions. The samples describe...
Triassic eclogite and blueschist facies rocks occur as a thrust sheet, 25-km long and over 2-km thick, in an Eocene fold-andthrust belt in northwest Turkey along the İzmir–Ankara suture. The thrust sheet consists mainly of metabasites with minor marble, phyllite and metachert, and rare lenses of serpentinite. The common blueschist facies mineral assemblage in the metabasites is sodic amphibole ...
Several relatively thin tectono-metamorphic slices have been recognized in the Cycladic eclogite– blueschist belt, through detailed studies on Ios, Sifnos, Syros, and Tinos. A sequence of distinct metamorphic mineral growth events has been documented. These recur in each tectonic slice, although individual slices are dominated by different events. To constrain the timing of these processes, the...
Eclogites from the Tian Shan high-pressure/low-temperature (HP/LT) metamorphic belt show evidence for successively increasing metasomatic alteration with increasing retrograde, blueschist-facies overprint. To constrain the source(s) of the metasomatizing fluid and to evaluate elemental and isotopic changes during this overprint, two sequences of eclogiteblueschist transitions were investigated:...
introduction the occurrence of blueschist metamorphic facies is believed to mark the existence of former subduction zones. this facies is represented in the main constituents of subduction-accretion complexes, where it occurs in separate tectonic sheets, imbricated slices, lenses, or exotic blocks within a serpentinite mélange (volkova et al., 2011). the evidence of the presence and maturity of...
We investigate the late Cretaceous blueschist-facies (480 °C-1.8 GPa) segment of Zagros suture zone, a well-preserved block-in-matrix paleo-subduction channel. aim to determine relative chronology, conditions deformation, and potential fluid sources processes associated with widespread occurrence lawsonite + clinopyroxene glaucophane veins aragonite-bearing hydraulic breccias. use multi-scale a...
چکیده ندارد.
Exhumed high-pressure/low-temperature (HP/LT) metamorphic rocks provide insights into deep (∼20–70 km) subduction interface dynamics. On Syros Island (Cyclades, Greece), the Cycladic Blueschist Unit preserves blueschist-to-eclogite facies oceanic- and continental-affinity that record structural thermal evolution linked to Eocene subduction. Despite decades of research, deformation history (P-T-...
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