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several sandstone classification scheme
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Over 50 classification have been proposed
Most of them involve a ternary Q-R-L/R (quartz, feldspar, lithic/rock fragments) plot for framework grains and a major subdivision based on the relative amount of matrix
Major subdivision
Arenite (0-15% of matrix)
Wacke (15-75% of matrix)
Mudstone (75-100% of matrix)
Sedimentary rocks
Q end (mono-qz, poly-qz, chert)
Feldspars (K-feldspars, plagioclase)
Lithic/Rock fragments (
Basis of Classification
Volcanic rocks
Hypabyssal and plutonic igneous rocks
Modified portrayal of Gilbert's classification of silicate sandstones incorporating Folk's dual maturity concepts
After Williams, H., F.J. Turner, and C.M. Gilbert, 1982; modified after Dott, R.H., Jr., 1964; taken from Boggs, S., Jr., 1987)
For this course we will use a classification of sandstones that is partially based on Tracey (p. 257) and partially basedTurner, and Gilbert (p. 326).
Classification of sandstones (McBride, 1963)
Sandstone composition is typically determined microscopically by identifying mineral composition at 300, 400, etc equally spaced points across a thin-section00
After Terry & Chilingar, 1955)