Webtrachyte, light-coloured, very fine-grained extrusive igneous rock that is composed chiefly of alkali feldspar with minor amounts of dark-coloured minerals such as biotite, amphibole, or pyroxene. Compositionally, trachyte is the volcanic equivalent of the plutonic (intrusive) rock syenite. Most trachytes show porphyritic texture in which abundant, large, well-formed … Web31 mei 2024 · What is the meaning of porphyritic? 1 : of or relating to porphyry. 2 : having distinct crystals (as of feldspar) in a relatively fine-grained base. Advertisements What is Adcumulate? Adcumulates are rocks containing ~100–93% accumulated magmatic crystals in a fine-grained groundmass.
Igneous textures - Wikipedia
Webrock formed slowly in an underground magma chamber. PORPHYRITIC TEXTURE - an igneous rock in which PHENOCRYSTS (large crystals) are surrounded by a fine groundmass (very small crystals). This shows that the large crystals had a chance to form in a magma while it was migrating and cooling. WebPorphyritic texture is a very common texture in igneous rocks in which larger crystals (phenocrysts) are embedded in a fine-grained groundmass. Porphyry is an igneous rock that contains larger crystals … north carolina short term rental agreement
Geology - rocks and minerals
WebA porphyritic texture is the texture of a rock with large phenocrysts and a background matrix of smaller crystals. To form this crystal contrast of smaller and larger minerals … Web6 mei 2024 · A porphyritic texture is developed when magma that has been slowly cooling and crystallising within the Earth’s crust is suddenly erupted at the surface, causing the … Web8 okt. 2024 · A porphyritic texture is Developed when magma that has been slowly cooling and crystallising within the Earth’s crust is suddenly erupted at the surface, causing the … north carolina si