WebPhenocryst a large crystal set in a fine matrix Poikilitic The state if a host phenocryst (oikocryst) containing many inclusions of other minerals Oikocryst A host phenocryst in poikilitic texture Groundmass (matrix, mesostasis) The glassy or finer-grained element in the porphyritic texture Seriate having a continuous graduation in size Aphyric WebDefinition and characterization of data fields included in appendix 1 (status and treatment of samples) ... Phenocryst size and crystallinity, rock textures, groundmass characteristics, and accessory mineral assemblages were also tabulated for each sample. Characteristics of the
phenocrystal - Wiktionary
Web1) Identification of the field relations between the igneous and non-igneous rocks. 2) Collection of samples: These samples have to be representative of the different igneous rocks in the province. They also have to be fresh (unaltered), and their size has to be considerably larger than the coarsest minerals in the sampled rock. Webmicro-+ phenocryst. Noun . microphenocryst (plural microphenocrysts) A very small crystal in a fine-grained porphyritic rock. 1983, U.S. Geological Survey Bulletin (page 9) The basalt of Goose Island of the Ice Harbor Member is unique for the occurrence of microphenocrysts of ilmenite and titanmagnetite. of us enschede
phenocryst Example sentences - Cambridge Dictionary
Webphenocryst (plural phenocrysts) ( mineralogy ) Any relatively large crystal embedded in a more fine-grained or glassy igneous rock 1965 , Gordon A Macdonald and Takashi … WebThese large crystals are known as "phenocrysts." They begin forming when a magma, which is cooling at depth, approaches the crystallization temperature of some of its minerals. These high-crystallization … Webdisplay a phenocryst assemblage of clinopyroxene + albitised plagioclase + ilmenite and rare amphibole. Accessory. apatite-needles in the Gendarme Dolerites, however, enable. distinction between the two. Characteristic primary mineral. assemblages of the intrusives of the Cobb Igneous Complex ofuscar imagem