Item talk:Q42586

Mindat Description

A mud-grade clastic-sedimentary-rock, composed of silt and clay, and lithified

Geoscience Ontology Description

Clastic sedimentary rock consisting of less than 30 percent gravel-size (2 mm) particles and with a mud to sand ratio greater than 1. Distinction of intrabasinal, diagenetic, or clastic genesis for very fine-grained carbonate minerals is interpretive in many cases. If there is uncertainty on the mudstone category based on intrabasinal vs epiclastic distinction required for clastic sedimentary rock-carbonate sedimentary rock categorization in this system, it is recommended to use the generic_mudstone category. This category is the union of the various fields labeled 'mudstone' with various qualifiers in Folk, 1954, Figure 1a, although Folk's (1954) category labeled 'mudstone' is a much more restricted category. The CGI category is equivalent to category labeled 'Mudrock' in SLTTs (2004), not to the category labeled 'Mudstone' adopted by that system from Folk (1954). Schnurrenberger, D., Russell, J. and Kelts, K., 2003, Classification of lacustrine sediments based on sedimentary components: Journal of Paleolimnology, v.29, p141-154.