Tag:geological=dyke

A geological dyke or dike is a sheet of rock that is formed in a fracture of a pre-existing rock body.  Dykes are sometimes embedded into another rock, visible as lines of different kind of rock and with different color and direction, or can be a stand alone wall when having resisted the erosion that removed some of the softer rock into which the dyke was originally intruded. They can look like man made walls and are then sometimes named and help with orientation.

For an artificial embankment, built to restrict the flow of water or other liquids, see man_made=dyke instead.

How to map

If it is a wall (like you can see them in the photos) you can either draw a way along the length of the dyke and tag it geological=dyke or draw a closed way around the extent of the dyke with the same tag.

If it is a vertical formation that can be seen from the side inside the rock body of a cliff as linear shaped differently colored rocky stripes you can add a node (like where it’s center is located if seen from top) or also a way along the length of the dyke (if that lengthy structure could be seen from top) with the same tag.

For alone standing walls or intrusions into the floor that are surrounded by different material (e.g. natural=sand) the tag is frequently combined with natural=bare_rock.

Photos

There are many examples which you can see in Wikipedia and Commons, magmatic walls especially in volcanic areas.

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  Board-like dyke below the summit of Pico Ruivo, Madeira.

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  Part of the magmatic dike running south from Shiprock in New Mexico.

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  Dark dikes on Baranof Island, Alaska.

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  Vertical basalt dikes cutting horizontal lava flows, Lord Howe Island, Australia.

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  Magmatic dikes radiating from West Spanish Peak, Colorado, U.S.A.

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  A magmatic dike (vertical) cross-cutting horizontal layers of sedimentary rock, in Makhtesh Ramon, Israel.