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The zeolite facies is the metamorphic facies with the lowest metamorphic grade. At lower temperature and pressure processes in the rock are called diagenesis. The facies is named for zeolites, strongly hydrated tectosilicates. It can have the following mineral assemblages: In meta-igneous rocks and greywackes:
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
However, Buchan facies series plot along line 3 and Barrovian at somewhat higher pressure and with the appearance of kyanite. The facies series have connections to plate tectonics. Facies series 1 is typical of contact metamorphism, but also found in regional metamorphosed rocks. Facies series 2 correlates with volcanic arc environments, and so ...
Often only part of the series can be found. Another metamorphic facies series is the Buchan series, that sees a fast increase in temperature but a relatively small increase in pressure. Characteristic minerals include andalusite, biotite and cordierite. The metamorphic prograde sequence of the Buchan zone series is:
Metamorphic facies is a classification system first introduced by Pentti Eskola in 1920 to classify particular metamorphic mineral assemblages that are stable under a range of P-T conditions. [ 54 ] [ 55 ] [ 1 ] Before the mid-1970s, geologists utilized the metamorphic facies classification to investigate metamorphic rocks and determined their ...
Based on inspection of extreme metamorphism and post-subduction magmatism at convergent plate margins, paired metamorphic belts are further extended to two contrasting metamorphic facies series: [7] one is blueschist to eclogite facies series that was produced by subducting metamorphism at low thermal gradients of <10 °C/km, and the other is ...
Solidified lava flow in Hawaii Sedimentary layers in Badlands National Park, South Dakota Metamorphic rock, Nunavut, Canada. Geology (from Ancient Greek γῆ (gê) 'earth' and λoγία () 'study of, discourse') [1] [2] is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. [3]
The metamorphic facies is not usually considered when classifying metamorphic rock based on protolith, mineral mode, or texture. However, a few metamorphic facies produce rock of such distinctive character that the facies name is used for the rock when more precise classification is not possible. The chief examples are amphibolite and eclogite ...