Ejecta ceiling

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An ejecta cover is a deposit of ejecta around an impact crater or a volcano .

Emergence

On impact ( impact ) of a small celestial body on the surface of a larger, for example the impact of a meteoroid (asteroid or comet) on the Earth's surface, a crater is formed by explosive ejection of material. The ejected materials are called ejecta .

The deposition of the ejecta after the impact takes place, at least in part, through the free flight of the ejected material, i.e. as " ballistic sedimentation". This creates a so-called “continuous ejecta blanket” - a continuous blanket of ejecta - around the impact crater . If the material contains larger chunks, secondary craters can also form.

In ejecta sheets caused by volcanoes, rock material and lava are ejected during explosive volcanic eruptions . For example, they are deposited as a layer of tuff or lapilli around the volcano and form a closed blanket that can be several meters thick, in some cases several dozen meters.

literature

  • Verne R. Oberbeck: The role of ballistic erosion and sedimentation in lunar stratigraphy. In: Reviews of Geophysics and Space Physics , Vol. 13 (1975), pp. 337-362, ISSN  0034-6853