GEOLOGY
PHYSICAL GEOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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glassy texture with gas pockets
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clastic texture with angular fragments
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bioclastic texture with cemented shell fragments
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foliated texture with microscopic mica crystals
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Detailed explanation-1: -Phyllite has fine-grained mica flakes in a preferred orientation, whereas slate has extremely fine clay flakes that achieve a preferred orientation, and schist has large flakes in a preferred orientation. Among foliated metamorphic rocks, it represents a gradation in the degree of metamorphism between slate and schist.
Detailed explanation-2: -Slate is a fine-grained metamorphic rock that exhibits a foliation called slaty cleavage that is the flat orientation of the small platy crystals of mica and chlorite forming perpendicular to the direction of stress.
Detailed explanation-3: -Phyllitic Texture Phyllitic rocks have very small grains and shiny, crenulated (crinkled) surfaces. They also split apart easily. Rocks with phyllitic texture, like this green phyllite, are slightly more metamorphosed than those with slaty texture. This sample has weak crenulation bands on its surface.