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  2. Volcanic rock - Wikipedia

    en.wikipedia.org/wiki/Volcanic_rock

    Volcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and metamorphic rocks and constitute an important element of some sediments and sedimentary rocks .

  3. List of places with columnar jointed volcanics - Wikipedia

    en.wikipedia.org/wiki/List_of_places_with...

    Basalt columns seen on Porto Santo Island, Portugal. Columnar jointing of volcanic rocks exists in many places on Earth. Perhaps the most famous basalt lava flow in the world is the Giant's Causeway in Northern Ireland, in which the vertical joints form polygonal columns and give the impression of having been artificially constructed.

  4. List of rock types - Wikipedia

    en.wikipedia.org/wiki/List_of_rock_types

    Trachybasalt – Volcanic rock – A volcanic rock with a composition between basalt and trachyte Hawaiite – Volcanic rock – a sodic type of trachybasalt, typically formed by ocean island volcanism; Trachyte – Extrusive igneous rock – A silica-undersaturated volcanic rock; essentially a feldspathoid-bearing rhyolite

  5. Metavolcanic rock - Wikipedia

    en.wikipedia.org/wiki/Metavolcanic_rock

    Metavolcanic rock is volcanic rock that shows signs of having experienced metamorphism. [1] In other words, the rock was originally produced by a volcano , either as lava or tephra . The rock was then subjected to high pressure, high temperature or both, for example by burial under younger rocks, causing the original volcanic rock to ...

  6. Category:Volcanic rocks - Wikipedia

    en.wikipedia.org/wiki/Category:Volcanic_rocks

    Pages in category "Volcanic rocks" The following 68 pages are in this category, out of 68 total. This list may not reflect recent changes. ...

  7. Subvolcanic rock - Wikipedia

    en.wikipedia.org/wiki/Subvolcanic_rock

    A subvolcanic rock, also known as a hypabyssal rock, is an intrusive igneous rock that is emplaced at depths less than 2 km (1.2 mi) within the crust, and has intermediate grain size and often porphyritic texture between that of volcanic rocks, which are extrusive igneous rocks, and plutonic rocks, which form much deeper in the ground. [1]

  8. Lava - Wikipedia

    en.wikipedia.org/wiki/Lava

    The top and side margins of an inflating lava dome tend to be covered in fragments of rock, breccia and ash. [71] Examples of lava dome eruptions include the Novarupta dome, and successive lava domes of Mount St Helens. [72] When a dome forms on an inclined surface it can flow in short thick flows called coulées (dome flows).

  9. Tuff - Wikipedia

    en.wikipedia.org/wiki/Tuff

    Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. [1] [2] Rock that contains greater than 75% ash is considered tuff, while rock containing 25% to 75% ash is described as tuffaceous (for example, tuffaceous sandstone). [3]