Cross-polarized light microscope image of an intergrowth of quartz and alkali feldspar in a granophyre (Muskox intrusion), as seen in thin section (Long dimension is 1.5 mm)
The texture is called granophyric. The texture can be similar to micrographic texture and to the coarser graphic intergrowths of quartz and alkali feldspar common in pegmatite. These textures document simultaneous crystallization of quartz and feldspar from a silicate melt at the eutectic point, perhaps in the presence of a water-rich phase. They may also be formed by crystallization when the magma is significantly undercooled, not necessarily under eutectic conditions.[3]
Granophyres typically are intrusive rocks that crystallized at shallow depths, and many have compositions similar to those of granites.[4] A common occurrence of granophyre is within layered igneous intrusions dominated by rocks with compositions like that of gabbro. In such occurrences, the granophyre may form as an end product of fractional crystallization of a parent mafic magma, or by melting of rocks into which the mafic magma was emplaced, or by a combination of the two processes.
Granophyre may also form as the uppermost stratigraphic layer resulting from melting of upper-middle crustal rocks by a meteorite impact. For example, the upper layer of the Main Mass of the 1850 Ma Sudbury Structure is composed of fine-medium grained granitic rocks with abundant granophyric textures.
^Lowenstern, J.B.; Clynne M.A.; Bullen T.D. (1997). "Comagmatic A-Type Granophyre and Rhyolite from the Alid Volcanic Center, Eritrea, Northeast Africa". Journal of Petrology. 38 (12). Oxford University Press: 1707–1721. doi:10.1093/petroj/38.12.1707.
^McDonnell, S.; Troll, V. R.; Emeleus, C. H.; Meighan, I. G.; Brock, D.; Gould, R. J. (October 2004). "Intrusive history of the Slieve Gullion ring dyke, Ireland: implications for the internal structure of silicic sub-caldera magma chambers". Mineralogical Magazine. 68 (5): 725–738. doi:10.1180/0026461046850215. ISSN 0026-461X.
This igneous rock-related article is a stub. You can help Wikipedia by expanding it.
granophyre, aɪər, gran, fire, from, granite, porphyry, subvolcanic, rock, that, contains, quartz, alkali, feldspar, characteristic, angular, intergrowths, such, those, accompanying, image, cross, polarized, light, microscope, image, intergrowth, quartz, alkali. Granophyre ˈ ɡ r ae n e f aɪer GRAN e fire 1 2 from granite and porphyry is a subvolcanic rock that contains quartz and alkali feldspar in characteristic angular intergrowths such as those in the accompanying image Cross polarized light microscope image of an intergrowth of quartz and alkali feldspar in a granophyre Muskox intrusion as seen in thin section Long dimension is 1 5 mm The texture is called granophyric The texture can be similar to micrographic texture and to the coarser graphic intergrowths of quartz and alkali feldspar common in pegmatite These textures document simultaneous crystallization of quartz and feldspar from a silicate melt at the eutectic point perhaps in the presence of a water rich phase They may also be formed by crystallization when the magma is significantly undercooled not necessarily under eutectic conditions 3 Granophyres typically are intrusive rocks that crystallized at shallow depths and many have compositions similar to those of granites 4 A common occurrence of granophyre is within layered igneous intrusions dominated by rocks with compositions like that of gabbro In such occurrences the granophyre may form as an end product of fractional crystallization of a parent mafic magma or by melting of rocks into which the mafic magma was emplaced or by a combination of the two processes Granophyre may also form as the uppermost stratigraphic layer resulting from melting of upper middle crustal rocks by a meteorite impact For example the upper layer of the Main Mass of the 1850 Ma Sudbury Structure is composed of fine medium grained granitic rocks with abundant granophyric textures See also editMicrographic texture Rock microstructure size shape and mutual relations of the particles of a rockPages displaying wikidata descriptions as a fallback Granite Type of igneous rock Eutectic Mixture with a lower melting point than its constituentsPages displaying short descriptions of redirect targets SolidusReferences edit Granophyre Lexico UK English Dictionary Oxford University Press Archived from the original on 2020 03 22 Granophyre Merriam Webster com Dictionary Retrieved 2016 01 23 Lowenstern J B Clynne M A Bullen T D 1997 Comagmatic A Type Granophyre and Rhyolite from the Alid Volcanic Center Eritrea Northeast Africa Journal of Petrology 38 12 Oxford University Press 1707 1721 doi 10 1093 petroj 38 12 1707 McDonnell S Troll V R Emeleus C H Meighan I G Brock D Gould R J October 2004 Intrusive history of the Slieve Gullion ring dyke Ireland implications for the internal structure of silicic sub caldera magma chambers Mineralogical Magazine 68 5 725 738 doi 10 1180 0026461046850215 ISSN 0026 461X nbsp This igneous rock related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Granophyre amp oldid 1167443126, wikipedia, wiki, book, books, library,
