WebNov 4, 2014 · A variety of genetic models have hitherto been suggested, which may be divided into three broad categories (Phillips 1974 ): (1) direct crystallization from a melt, … WebWhat is Myrmekitic texture? Myrmekitic texture defined by wormy (rounded) intergrowths o quartz and K-feldspar in plagioclase which is adjacent to K-feldspar. Probably forms as a result of subsolidus exchange. Compare this texture to micrographic texture. Is perthite a mineral? Perthite is an intergrowth of two different Feldspar minerals in ...
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Webmyrmekite, irregular, wormy penetration by quartz in plagioclase feldspar; these wartlike, wormlike, or fingerlike bodies may develop during the late stages of crystallization of … WebOct 8, 2016 · Note that a common type of symplectitic intergrowth is the myrmekitic texture commonly observed in granites, where wormy quartz occurs in plagioclase crystals in contact with biotite.... loacker wonfurt
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WebThe trace element abundances of high-Ti brown amphibole, plagioclase, and zircon in veins, as well as the presence of myrmekitic texture in the studied felsic rocks support crystallization origin from highly-evolved melts, probably controlled by … WebJan 1, 1974 · Another comment is that no relationship need exist be- tween the regular 'graphic' or the 'granophyric' textures (considered to be more indicative of simultaneous crystallization) and the 'wormy' myrmekitic texture (cf. Makhlayev 1973:181, Sathe 1964.335), as has been amply demon- strated by Barker (1970). These quartz-plagioclase intergrowths are associated with and commonly in contact with potassium feldspar. Myrmekite is formed under metasomatic conditions, usually in conjunction with tectonic deformations. It has to be clearly separated from micrographic and granophyric intergrowths, which are … See more Myrmekite is a vermicular, or wormy, intergrowth of quartz in plagioclase. The intergrowths are microscopic in scale, typically with maximum dimensions less than 1 millimeter. The plagioclase is sodium-rich, usually See more The word myrmekite is derived from the Ancient Greek μὑρμηχἰα (wart) or μὑρμηξ (ant) and was used by Jakob Sederholm in 1899 for the first time to describe these structures. See more During Ca- metasomatism myrmekite can be formed under different circumstances: • Ca-metasomatism of deformed K-feldspar in magmatic rocks • Ca-metasomatism of … See more During progressive deformation in mylonitic, ductile shear zones myrmekite is commonly concentrated in shortening quarters in the rim … See more During K-metasomatism of plagioclase several different types of myrmekite can appear: • rim myrmekite • wartlike myrmekite • ghost myrmekite See more A first variety of this type of metasomatism affects only enclaves within a granitoid. Here the influx of Na-rich fluids in the temperature range 450 °C to 650 °C from the host leads … See more Myrmekite can appear in many different rock types and different geologic settings. Typically it occurs in granites and similar igneous rocks (granitoids, diorites, gabbros) and in See more india mother\u0027s day 2023