Schluffstein (also siltstone ) is a clastic sedimentary rock in which mineral grains with a grain size of 0.002 to 0.063 mm equivalent diameter predominate. Its average grain size is between claystone and fine sandstone . Siltstones are mostly siliciclastic and the silt particles are usually made of quartz .
Siltstones are made from unconsolidated silt or silt. Such sediments are typical of a relatively calm deposit environment , such as lakes , lowlands away from rivers or the open shelf . A silt-rich loose sediment can be solidified into a siltstone by a sequence of geological processes that are collectively referred to as diagenesis . The solidification occurs as a result of the subsidence of the loose sediment in greater depths - usually caused by the normal subsidence of the deposit area - and the resulting increase in pressure andTemperature .
- Hans Füchtbauer (Ed.): Sediments and sedimentary rocks. 4th, completely revised edition. Schweizerbart, Stuttgart 1988, ISBN 3-510-65138-3 , pp. 185 ff.