Information AboutPlutonic |
| CATEGORIES ABOUT INTRUSION | |
| volcanology | |
| petrology | |
| igneous rocks | |
| SHOPPER'S DELIGHT | |
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:''Plutonic redirects here, you may have meant Platonic .'' , an igneous intrusion exposed when the surrounding softer rock eroded away.]] In Geology , an intrusion is a body of Igneous Rock that has Crystal lized from a molten Magma below the surface of the Earth . Bodies of magma that solidify underground before they reach the surface of the earth are called '''plutons''', named for Pluto , the Roman God of the Underworld . Correspondingly, rocks of this kind are also referred to as '''igneous plutonic rocks''' or '''igneous intrusive rocks'''. This is to be contrasted with Extrusive Rocks . VARIETIES Intrusive rocks include all varieties of igneous rocks from coarse-grained, phaneritic Granite s of large Batholith s to very fine grained, aphanitic, Rhyolite s in Volcanic necks or feeder pipes. In composition, intrusive rocks also include the entire sequence of igneous rock types from the dense and dark ultramafic Peridotite s to the very light-colored and low-density alkali granites and Syenite s. A well-known example of an igneous intrusion is Devil's Tower in Wyoming , USA . in Rio De Janeiro .]] STRUCTURAL TYPES Intrusive rocks also exist in a wide range of forms from mountain range sized batholiths to thin vein-like fracture fillings of Aplite . Structural types include:
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