Item talk:Q41290

Mindat Description

Clastic sedimentary rock, composed of clasts of detrital rock and mineral fragments

Geoscience Ontology Description

Sedimentary rock in which at least 50 percent of the constituent particles were derived from erosion, weathering, or mass-wasting of pre-existing earth materials, and transported to the place of deposition by mechanical agents such as water, wind, ice and gravity. The conglomerate, sandstone, mudstone, and wackestone categories are not defined as kinds of clastic sedimentary rocks because rocks meeting their purely grainsize based definitions might also be iron-rich, phosphatic, or carbonate. This is based on GeoSciML allowance to assign rocks to more than one lithology category. For example to categorize a rock as a clastic conglomerate requires assignment ot the 'clastic sedimentary rock' category and to the 'conglomerate' category. Particularly for fine-grained sedimentary rocks, distinction of 'intrabasinal' versus 'clastic' genesis can be very interpretive. In practice the use of clastic mudstone terminology as opposed to carbonate mudstone terminology may be dermined by a priori knowledge about the rock being categorized. If it is associated with other clastic rocks, the clastic categories will be favored, if with cabonate rocks, the carbonate categories will be favored.