Keyword Definition

Clastic sandstone with more than 10 percent matrix of indeterminate detrital or diagenetic nature. Matrix is mud size silicate minerals (clay, feldspar, quartz, rock fragments, and alteration products).


Distinction from mudstone is based on inference that less that 50 percent of the mud size fraction (matrix) is original mud size detrital particles. May also grade into diamictite or conglomerate based on size distribution of discernible particles. If more than 50 percent of rock is detrital particles of intrabasinal orgin and carbonate composition, categorize as carbonate wackestone.

See Dickinson (1970) for discussion of interpretation of undiscernible matrix in diagenetically altered lithic clastic rocks. Dickinson, W.R., 1970, Interpreting detrital modes of graywacke and arkose: Journal of Sedimentary Petrology, v. 40, p. 695-707.

Suggested boundaries between wacke and arenite range from 5 to 15 percent matrix

Term is typically applied to diagenetically altered volcanic-lithic clastic rocks in which the definition of the original clasts has been obscured.

Pettijohn, Potter, Siever, 1972, Sand and Sandstone: New York, Springer Verlag, 681 p.

See Also: graywacke

Parents: Sandstone (56)

[Description taken from GeoSciML SimpleLithology201012.rdf]

Hierarchical classification

Sample >> Lithosphere >> Rock >> Whole >> Rock >> Sedimentary >> Generic sandstone >> Sandstone >> Wacke



Category: Analysed material

The different kinds of sample material collected in the field have been classified hierarchically. Examples: “till”, “soil”, “vegetation”. Taken from the “Sample_Types_SHARED” database table.

Date modified: