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Spherules

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Encyclopedia of Astrobiology

Synonyms

Distal impact ejecta, Microkrystite, Microtektite

Definition

Spherules are distal deposits of meteorite impacts. They are spherical droplets that can form in two ways: as silicate splash particles of ejected impact melt and as condensates from the rock-vapor plume. Glassy spherules that do not contain any crystallites are called microtektites (Glass 1990). These often contain vesicles and are commonly originated as melt spherules. Crystal-bearing spherules, in contrast, are typical to have originated from vapor condensates and are termed microkrystites (Glass and Bohor 1988). Spherules can be less than a hundred micrometers to a few millimeters in diameter. Spherules may be deposited globally or in strewn fields which radiate from the crater.

Overview

Spherule beds are sedimentary layers that are composed entirely of spherules or, if reworked, may contain detrital material. Pure spherule beds can be up to a few decimeters thick. The impact-related origin can be recognized by...

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Correspondence to Nadja Drabon .

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Drabon, N. (2014). Spherules. In: Amils, R., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-27833-4_5234-2

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  • DOI: https://doi.org/10.1007/978-3-642-27833-4_5234-2

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