As allochthonous (neologism from the Greek words άλλος Allos , otherwise ',' foreign 'and χθών Chthon , Earth') is called in geology from the education center away or by transport processes in strange surroundings geological objects spent several orders of magnitude. In contrast, there are autochthonous formations (“on site”).
On a local and even smaller scale, the term refers to mineral grains and rock fragments from particle size to house-sized blocks, as well as organic material as constituents of sedimentary rocks . If a sedimentary rock consists predominantly of allochthonous components, the rock itself is also classified as allochthonous. Typical allochthonous sedimentary rocks are sandstones and siltstones . They are also known as detritic . In contrast to this, limestone and coal are predominantly formed indigenously.
On a regional scale, the attribute allochthonous mostly refers to tectonic nappes (as a synonym for nappes also as noun the allochthon used). Even larger non-local units are the terrane moved by plate tectonic transport , the geology of which deviates from the basement geology prevailing on a continent or a larger part of a continent .
- Collective of authors: Lexicon of Geosciences. Volume I. Spectrum Academic Publishing House, Heidelberg / Berlin 2000, ISBN 3-8274-0299-9 , p. 56