Living Reference Work Entry

Encyclopedia of Planetary Landforms

pp 1-6

Date: Latest Version

Dike (Igneous)

  • Jarmo KorteniemiAffiliated withEarth and Space Physics, Department of Physics, University of Oulu Email author 

Definition

A magmatic vertical sheet intrusion that has penetrated into a preexisting body of rock.

Synonyms

Magmatic dike. Alternative spelling: dyke; Vertical intrusion

Description

A solidified near-vertical subsurface magma body that penetrates through one or more layers of preexisting rock bodies or layers (regardless of rock type). The thickness of a dike is much smaller (cm to meters) than the other dimensions (kilometers), forming a sheetlike structure. Similar but lateral intrusions that form between rock layers are called sills (Magmatic intrusion structure). Dikes per se do not penetrate to the surface, but several landform types may betray their presence. Areal and differential erosion may expose them directly as exhumed dikes. Dike-indicative features are linear or slightly curvilinear over long distances (Head et al. 2006), often appearing in subparallel groups (Korteniemi et al. 2010). They generally cross terrain irrespective of topography (Head et al. 2006). During dike form ...

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