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Partial melting is the phenomenon that occurs when a rock is subjected to temperatures high enough to cause certain minerals to melt, but not all of them. Partial melting is an important part of the formation of all igneous rocks and some metamorphic rocks (e.g., migmatites), as evidenced by a multitude of geochemical, geophysical and petrological studies.
Anatexis. Anatexis (via Latin from Greek roots meaning "to melt down") is the partial melting of rocks. [1] Traditionally, anatexis is used specifically to discuss the partial melting of crustal rocks, while the generic term "partial melting" refers to the partial melting of all rocks, in both the crust and mantle. [citation needed]
Adakite. Adakites are volcanic rocks of intermediate to felsic composition that have geochemical characteristics of magma originally thought to have formed by partial melting of altered basalt that is subducted below volcanic arcs. [2] Most magmas derived in subduction zones come from the mantle above the subducting plate when hydrous fluids ...
Migmatite on the coast of Saaremaa, Estonia. Intricately-folded migmatite from near Geirangerfjord, Norway. Migmatite is a composite rock found in medium and high-grade metamorphic environments, commonly within Precambrian cratonic blocks. It consists of two or more constituents often layered repetitively: one layer is an older metamorphic rock ...
The mafic minerals in the TTG rock body, possibly biotite, were weathered, which introduced a brownish coating on the TTG rock surface. Tonalite–trondhjemite–granodiorite (TTG) rocks are intrusive rocks with typical granitic composition (quartz and feldspar) but containing only a small portion of potassium feldspar.
Magmatism along strike-slip faults is the process of rock melting, magma ascent and emplacement, associated with the tectonics and geometry of various strike-slip settings, most commonly occurring along transform boundaries at mid-ocean ridge spreading centres [1] and at strike-slip systems parallel to oblique subduction zones. [2]
Diorite results from the partial melting of a mafic rock above a subduction zone. It is found in volcanic arcs , and in cordilleran mountain building , such as in the Andes Mountains . However, while its extrusive volcanic equivalent, andesite, is common in these settings, diorite is a minor component of the plutonic rocks, which are mostly ...
The interpretation of S-type granites are that they are sourced from the partial melting of sedimentary rocks (supracrustal) that have been through one or more cycles of weathering. Evidence for this include aluminium and silica enrichment, caused by the weathering process of the source rock.