Outcrop of Gabbro Xenoliths in G3-Granite
by Metwally Hamza, Full Geologist, Egypt
- Gabbro is a mafic, basic, dark igneous rock. Contains from 45% to 55% silica (SiO2). The main essential minerals are olivine, pyroxene, amphibole, muscovite, and biotite. The accessory minerals are ilmenite, sphene, spinel, and sulfide.
- G3-Granite "generally Granite" is a felsic, acidic, light igneous rock. Contains more than 66% silica (SiO2). The main essential minerals are muscovite, quartz, plagioclase, alkali-feldspars. The accessory minerals are spinel. Generally, G3-Granite is alkali to per-alkaline granite, includes riebeckite.
- There are two main terms in petrological studies; xenolith and off-shot. Xenoliths "Enclaves" are old rocks in other containing new rocks, which cannot be metamorphosed by these new ones. Off-shots are new rocks in other containing old rocks, which are stable in very extreme conditions.
Taken and Itemized by Metwally Hamza.
Taken on 30
Submitted on 26 March 2021
Credit: Metwally Hamza (distributed via imaggeo.egu.eu)
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