Lutite
Lutite is old terminology, which is not widely used, by Earth scientists in field descriptions for fine-grained,
claystone, mudstone, shale, and siltstone. It is equivalent to the term mudstone and the Greek-derived term pelite.[1][2] Lutite was first used in 1904 by Grabau,[3] who derived it from lutum, the Latin word for mud.[4] He also proposed a number of prefixes to be used with and attached to "lutite" in order to designate various types of lutites. None of these prefixes are used by Earth scientists nowadays.[1]
Pettijohn [5] gives the following descriptive terms based on grain size, avoiding the use of terms such as "clay" or "argillaceous" which carry an implication of chemical composition:
| Texture | Common | Greek | Latin |
|---|---|---|---|
| Coarse | gravel(ly) | psephite (psephitic) | rudite (rudaceous) |
| Medium | sand(y) | psammite (psammitic) | arenite (arenaceous) |
| Fine | clay(ey) | pelite (pelitic) | lutite (lutaceous) |
References
- ^ ISBN 978-3-540-22157-9
- ISBN 0-922152-76-4
- ^ Grabau, A.W. (1904) On the classification of sedimentary rocks. American Geologist. vol. 33, pp. 228-247.
- Perseus Project.
- ISBN 0-06-045191-2