Definition of Porphyroblast. Meaning of Porphyroblast. Synonyms of Porphyroblast

- A porphyroblast is a large mineral crystal in a metamorphic rock which has grown within the finer grained matrix. Porphyroblasts are commonly euhedral...
- off from either side of the porphyroblast within the strain shadows.[citation needed] During shearing, the porphyroblast may rotate, to form a characteristic...
- forms a re-entrant as it is absorbed by the growth of the andalusite porphyroblast. The cycle of growth-****ation-growth then repeats itself, creating...
- followed by exhumation (uplift). The porphyroblast of garnet was formed during high grade metamorphism while the porphyroblast of cordierite was formed during...
- may have been phenocrysts or porphyroblasts in the original rock. Porphyroclasts are often confused with porphyroblasts. The latter are also large crystals...
- megaphenocrysts. In metamorphic rocks, crystals similar to phenocrysts are called porphyroblasts. Phenocrysts are more often found in the lighter (higher silica) igneous...
- characterized by co****, irregular grains, including some larger grains (porphyroblasts.) Sandstone has been used since prehistoric times for construction,...
- metamorphic rock characterized by an abundance of platy minerals. In this example, the rock has prominent sillimanite porphyroblasts as large as 3 cm (1.2 in)....
- schistosity. Though not a defining characteristic, schists very often contain porphyroblasts (individual crystals of unusual size) of distinctive minerals, such...
- marble, charnockites and other non-foliated metamorphic rocks without porphyroblasts. Characteristics defining granoblastic texture include: grains visible...