Rudstone

Rudstone is a type of carbonate rock.

Rudstone with micrite. Width of picture is 36mm
Rudstone with sparite. Width of picture is 36mm

The Dunham classification (Dunham, 1962[1]) did not consider grain size as a criterion for the description of carbonate lithologies. In an attempt to rectify this perceived deficiency, Embry & Klovan (1971[2]) introduced the terms rudstone (grain supported) and floatstone (matrix supported) for coarse-grained allochthonous carbonates. Following a survey of the use of the Dunham classification, Lokier and Al Junaibi (2016)[3] clarified the definition of a rudstone as "a carbonate-dominated rock where more than 10% of the volume is comprised of grains larger than 2 mm and these grains support the fabric of the rock."

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