What is equigranular geology?
Definition of equigranular : having or characterized by crystals of nearly the same size a rock of equigranular texture.
What is equigranular rock?
An equigranular material is composed chiefly of crystals of similar orders of magnitude to one another. Basalt and gabbro commonly exhibit an equigranular texture.
What is a crystalline texture?
Crystalline textures include phaneritic, foliated, and porphyritic. Phaneritic textures are where interlocking crystals of igneous rock are visible to the unaided eye. Foliated texture is where metamorphic rock is made of layers of materials.
What is intergranular texture?
Intergranular texture – a texture in which the angular interstices between plagioclase grains are occupied by grains of ferromagnesium minerals such as olivine, pyroxene, or iron titanium oxides.
How is equigranular texture formed?
The texture is termed as equigranular when all the component minerals are of approximately equal dimensions and as inequigranular when some minerals in the rock are exceptionally larger or smaller than the other.
What is Leucocratic?
Definition of leucocratic of a mineral or rock. : having a light color — compare melanocratic, mesocratic.
What does crystalline mean in geology?
crystalline rock, any rock composed entirely of crystallized minerals without glassy matter. Intrusive igneous rocks—those that congeal at depth—are virtually always crystalline, whereas extrusive igneous rocks, or volcanic rocks, may be partly to entirely glassy.
What do you mean by crystalline?
Definition of crystalline 1 : resembling crystal: such as. a : strikingly clear or sparkling crystalline air a crystalline lake. b : clear-cut. 2 : made of crystal : composed of crystals. 3 : constituting or relating to a crystal.
How is equigranular texture formed in igneous rocks?
Equigranular Textures: All those textures in which majority of constituent crystals of a rock are broadly equal in size are described as equigranular textures. In igneous rocks, these textures are shown by granites and felsites and hence are also often named as granitic and felsitic textures.
What is texture describe the Inequigranular texture of igneous rock in detail?
Inequigranular texture (i) Porphyritic texture : When an igneous rock contains large crystals some minerals set in a matrix which is much finer grained or even glassy, the texture is called “Porphyritic”. The large crystals are called “Phenocrysts” and fine grained material is called “groundmass”.
What is Poikilitic texture in geology?
Poikilitic texture describes the occurrence of one mineral that is irregularly scattered as diversely oriented crystals within much larger host crystals of another mineral.
What is Hypabyssal igneous rock?
A subvolcanic rock, also known as a hypabyssal rock, is an intrusive igneous rock that is emplaced at depths less than 2 km (1.2 mi) within the crust, and has intermediate grain size and often porphyritic texture between that of volcanic rocks and plutonic rocks.
What is the meaning of equigranular?
Definition of equigranular. : having or characterized by crystals of nearly the same size a rock of equigranular texture.
What is inequigranular texture?
Inequigranular: The mineral of the rock will be of different sizes. (c) Ophitic texture. Bigger grains surrounded by smaller grains. Granite porphyry, Syenite porphyry and Diorite porphyry.
What is the difference between aphanitic and equigranular?
Aphanitic (“AY-fa-NIT-ic”) rocks have mineral grains that are mostly too small to be seen with the naked eye or a hand lens, like this rhyolite. Basalt is another igneous rock with the aphanitic texture. Rocks with equigranular (“EC-wi-GRAN-ular”) have mineral grains that are generally the same size. This example is a granite.
What are the two types of textures in geology?
Directive textures . Intergrowth textures and . Intergranular textures. � All those textures in which majority of constituent crystals of a rock are broadly equal in size are described as equigranular textures. � In igneous rocks, these textures are shown by granites and felsites and hence are also often named as granitic and felsitic textures