What is Granoblastic texture?
What is Granoblastic texture?
Granoblastic is an adjective describing an anhedral phaneritic equi-granular metamorphic rock texture. Granoblastic texture is typical of quartzite, marble, charnockites and other non-foliated metamorphic rocks without porphyroblasts.
Where are Mylonites found?
Mylonite is a fine-grained rock that containes intensely flattened minerals. A boulder on the coast of Varanger Peninsula in Norway. Mylonites are foliated, but the foliation is generally passive. It means that the foliation is not controlling how the rock breaks.
What is Hornfelsic texture?
A hornfels is a thermally metamorphosed rock; hence, the textures of hornfelses are the result of crystallization—recrystallization at elevated temperatures and low to moderate pressures in the absence of directed pressure.
What is Lepidoblastic texture?
: relating to a texture in a metamorphic rock corresponding to the scaly texture of an igneous rock.
How is Diablastic texture formed?
Decussate (or diablastic) texture is a metamorphic rock texture comprising of equigranular, interlocking, randonly orientated platy, tabular, prismatic or elongate minerals. The texture arises to minimise surface energy in a rock with elongate crystals and is thus similar to a granoblastic texture.
What is Corona texture?
Corona texture: several concentric layers of one or more minerals completely encircling an older phase. The layers (which range from one to five in number) represent a sequence of reactions that have taken place (none to completion) to replace the mineral in the core or center of the corona.
How mylonites are formed?
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism.
Why do we get mylonite?
Mylonite (from the Greek, “myle” means “mill”) caused by intensive grinding and crushing of various rocks along tectonic zones influenced by strong pressure or dynamic stress.
What type of rock is basalt?
Basalt is a hard, black volcanic rock. Basalt is the most common rock type in the Earth’s crust. Depending on how it is erupted, basalt can be hard and massive (Figure 1) or crumbly and full of bubbles (Figure 2).
What is Porphyroclastic texture?
the uneven granular texture of a rock caused by the presence of large crystals, or porphyroblasts, in a fine-grained groundmass. Unlike phenocrysts, porphyroblasts form during recrystallization in the course of metasomatism of solid rock.