What is the difference between the way intrusive and extrusive igneous rock is formed?
Extrusive rocks are formed on the surface of the Earth from lava, which is magma that has emerged from underground. Intrusive rocks are formed from magma that cools and solidifies within the crust of the planet. If lava cools almost instantly, the rocks that form are glassy with no individual crystals, like obsidian.
Are all sandstones the same?
Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black.
Is rhyolite Aphanitic or porphyritic?
Rhyolite is extrusive equivalent of granite magma. It is composed predominantly of quartz, K–feldspar and biotite. It may have any texture from glassy, aphanitic, porphyritic, and by the orientation of small crystals reflecting the lava flow.
Is mafic intrusive or extrusive?
Basalt and gabbro are the extrusive and intrusive names for mafic igneous rocks, and peridotite is ultramafic, with komatiite as the fine-grained extrusive equivalent.
What is the meaning of Phaneritic?
[ făn′ə-rĭt′ĭk ] Of or relating to an igneous rock in which the crystals are so coarse that individual minerals can be distinguished with the naked eye. Phaneritic rocks are intrusive rocks that cooled slowly enough to allow significant crystal growth. Compare aphanitic.
What is the difference between intrusive and extrusive igneous rocks quizlet?
The difference between intrusive and extrusive igneous is that, intrusive rock is one that forms when magma cools within Earth. Extrusive igneous rock is one that, forms when lava cools on Earths surface.
What kind of rock is shale?
shale, any of a group of fine-grained, laminated sedimentary rocks consisting of silt- and clay-sized particles. Shale is the most abundant of the sedimentary rocks, accounting for roughly 70 percent of this rock type in the crust of the Earth. Shales are often found with layers of sandstone or limestone.
What is phaneritic and aphanitic?
APHANITIC TEXTURE – Igneous rocks that form on the earth’s surface have very fine-grained texture because the crystals are too small to see without magnification. PHANERITIC TEXTURE – Igneous rocks with large, visible crystals because the rock formed slowly in an underground magma chamber.
How do you identify Aphanitic rocks?
Aphanitic texture is a fine grained texture but the crystals are too small to see. Porphyritic texture is composed of crystals of two different sizes. Typically the large crystals (phenocrysts) are visible while the smaller crystal are not (referred to as groundmass). Glassy texture is the most readily recognized.
What is the difference between aphanitic and phaneritic rocks?
A) phaneritic or coarse grained-textures are typical of intrusive (cools slowly) igneous rocks. The minerals are sufficiently large to see each individual crystal with the naked eye. aphanitic or fine grained- extrusive rocks (cools quickly, the minerals are not distinguishable to the naked eye.
What kind of rock has an aphanitic texture?
Aphanitic – This texture describes very fine grained rock where individual crystals can be seen only with the aid of a microscope, i.e. the rock is mostly groundmass. An aphanitic texture is developed when magma is erupted at the Earth’s surface and cools too quickly for large crystals to grow. Additionally, what is Aphanitic and Phaneritic?
How are Phaneritic textures formed in igneous rocks?
Phaneritic (phaner = visible) textures are typical of intrusive igneous rocks, these rocks crystallized slowly below Earth’s surface. As magma cools slowly the minerals have time to grow and form large crystals. Porphyritic textures develop when conditions during cooling of a magma change relatively quickly.
How are intrusive igneous rocks different from aphanitic rocks?
Intrusive igneous rocks thus have coarse-grained, or phaneritic, textures with visible crystals, and extrusive igneous rocks have fine-grained, or aphanitic, texture. Volcanic glass , called obsidian , forms when lava is quenched and solidified so quickly that the silicate ions in the melt form no orderly atomic structure.