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What is planar foliation?
foliation, planar arrangement of structural or textural features in any rock type but particularly that resulting from the alignment of constituent mineral grains of a metamorphic rock of the regional variety along straight or wavy planes.
What is the metamorphic texture?
Metamorphic texture is the description of the shape and orientation of mineral grains in a metamorphic rock. Metamorphic rock textures are foliated, non-foliated, or lineated are described below.
How is foliated metamorphic rock formed?
Foliated Metamorphic Rocks: Foliation forms when pressure squeezes the flat or elongate minerals within a rock so they become aligned. These rocks develop a platy or sheet-like structure that reflects the direction that pressure was applied.
How does metamorphic foliation develop?
What is gneissic texture?
The “gneissic texture” refers to the segregation of light and dark minerals. It is indicative of high-grade metamorphism where the temperature is high enough, say 600-700 °C, so that enough ion migration occurs to segregate the minerals. Gneiss often forms from the metamorphism of granite or diorite.
What’s gneissic texture?
What is another term for Aphanitic?
Aphanitic is a descriptive term for small crystals, and phaneritic for larger ones. Aphanitic rocks are further described as either microcrystalline or cryptocrystalline, according to whether or not their individual constituents can be resolved under the microscope.
How is Aphanitic texture formed?
An aphanitic texture is developed when magma is erupted at the Earth’s surface and cools too quickly for large crystals to grow. This texture is exhibited by some volcanic rocks.
What is the difference between planar and planar graph?
The graphs are the same, so if one is planar, the other must be too. However, the original drawing of the graph was not a planar representation of the graph. When a planar graph is drawn without edges crossing, the edges and vertices of the graph divide the plane into regions.
How do textures in metamorphic rocks reflect the mode of deformation?
Since deformation involves the application of differential stress, the textures that develop in metamorphic rocks reflect the mode of deformation, and foliations or slatey cleavage that develop during metamorphism reflect the deformational mode and are part of the deformational structures.
Why is the oxide layer used in planar devices?
The oxide layer was indeed found to protect the junctions, as Hoerni had predicted. Planar devices also proved to have better electrical characteristics – particularly far lower leakage currents, which is critical in computer logic design.
Why do dark colored minerals form elongated crystals instead of sheets?
Because the dark colored minerals tend to form elongated crystals, rather than sheet- like crystals, they still have a preferred orientation with their long directions perpendicular to the maximum differential stress.