نتایج جستجو برای: regional metamorphism
تعداد نتایج: 207800 فیلتر نتایج به سال:
چکیده ندارد.
On the basis of microstructural evidence it is clear that SMC metapelites have experienced at least two regional (RM1, RM2) and one contact metamorphism (CM). During RM2, several porphyroblasts including kyanite, andalusite, staurolite, cordierite, garnet and fibrous sillimanite have grown in the mica - schists. In order to estimate the PT condition of metamorphism of metapelites, we used catio...
The formation of porphyroblasts by replacement and displacement of pre-existing S surfaces is examined in the light of textural evidence displayed by sediments hornfelsed by the Bushveld Igneous Complex. Helicitic biotite, staurolite, and cordierite all show replacement and displacement textures, the former being more common. The evidence indicates that porphyroblasts arc capable of creating lo...
چکیده ندارد.
Garnet bearing staurolite schists comprise an important part of regional metamorphic succession in the Hamedan area (north of the Sanandaj-Sirjan zone). These rocks contain staurolite and garnet porphyroblats that lie in a matrix which is composed of biotite, muscovite and quartz. The staurolites in Fe-rich and show little chemical composition diversities. Almandin is the most important compone...
Garnet-whole rock and garnet-mineral isochrons were determined on granulite facies gneisses and amphibolites from the Archean Pikwitonei Granulite Domain of the Superior Province, and the Proterozoic Central Gneiss Belt and Adirondack Highlands of the Grenville orogen. The Sm-Nd ages obtained from Archean garnets 0.1-0.5 cm in length are 30-110 Ma younger than the U-Pb ages obtained on the same...
TEM and XRD techniques were used to study crystal growth characteristics of the fabric-forming phyllosilicates which developed in response to low-grade metamorphism and tectonic imbrication in part of the Southern Uplands thrust terrane. Prograde regional metamorphism, ranging from late diagenesis through the anchizone to the epizone, was accompanied by the development of a slaty cleavage which...
The Deh-Salm Metamorphic Complex (DMC) is composed of metapelite, metabasite, metaperidotite, and calc-silicate rocks and is one of the few outcrops of the Lut block’s basement which emerged near to the Sistan suture zone. In the eastern part of the Deh-Salm metamorphic complex, the calc-silicate and marble appeared in the form of elongated tectonic lenses that have been metamorphosed in simila...
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