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Porphyritic Rocks are rocks that have big and small crystal's like the Igneous Rock "Andesite".
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∙ 11y ago
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Is porphyritic texture is not a feature of sedimentary rocks?
Porphyritic texture is a feature of some igneous rocks, not sedimentary rocks.
What are Igneous rocks that have large crystals and small crystals?
Such rocks are called porphyritic.
What are rocks containing two different sizes of crystal called?
Such rocks are porphyritic.
What Mineral alignment in a metamorphic rock usually gives the rock a porphyritic texture?
A porphyritic texture can be a feature of igneous rocks, but 'porphyritic' is not used to describe metamorphic rock texture. Metamorphic rocks can be foliated or non-foliated, terms used to describe mineral alignment or banding, or the lack thereof.
What igneous rocks are both intrusive and extrusive?
Porphyritic igneous rocks can display both intrusive and extrusive characteristics.
Are sedimentary rocks that form when minerals come out of a solution classified as porphyritic?
No. I believe they are called chemical precipitate sedimentary rocks. Yes, I'm sure they're called that. Absolutely! Porphyritic is a term usually applied to igneous rocks, having to do with mineral formation and rock texture.
Igneous rocks with a two-stage intrusive-extrusive origin are recognized by a texture which is?
porphyritic
What are the crystal structures in porphyritic rocks?
They're called phenocrysts, allowed to slowly cool in magma before eruption of the magma.
Is felsic porphyritic extrusive?
Some felsic rocks are and some are not. The term felsic is a description of an ingeous rock's composition, not its texture or where it occurs.
What is a porphyritic texture?
A porphyritic texture is displayed in an igneous rock containing large isolated crystals (phenocrysts) in a mass of fine textured crystals . Porphyritic texture indicates that a magma has gone through a two stage cooling process. The magma has cooled sufficiently underground to allow some minerals to crystallize and grow in size; the magma is then expelled above ground where the remaining liquid magma solidifies quickly, allowing only small crystals to develop.See link below for a picture of a porphyritic texture in a rock.
Which igneous rock cools the fastest glassy aphanitc pegmatic and porphyritic?
Glassy igneous rocks cool the fastest. The most likely had more nucleation. Pegmatic cooled the slowest, which is why its crystals are larger than 1 cm. Phaneritic is the next slowest in cooling. Porphyritic has slow then rapid cooling, while aphanitic igneous rocks also have rapid cooling.
The average composition of rocks comprising a large composite cone or stratovolcano is similar to what?
The average composition of rocks comprising a large composite cone or stratovolcano is the same with an andesitic magma. It has an intermediate composition, with aphanitic to porphyritic texture.
