A rock fragment, in sedimentary geology, is a sand-sized particle or

sand grain Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural cl ...

that is made up of multiple grains that are connected on the grain scale. These can include grains which are sand-sized themselves (a

granitic A granitoid is a broad term referring to a diverse group of coarse-grained igneous rocks that are widely distributed across the globe, covering a significant portion of the Earth's exposed surface and constituting a large part of the continental ...

rock fragment), or finer-grained materials (

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

fragments). This definition is used for QFR ternary diagrams,

provenance Provenance () is the chronology of the ownership, custody or location of a historical object. The term was originally mostly used in relation to works of art, but is now used in similar senses in a wide range of fields, including archaeology, p ...

analysis, and in the

Folk classification The Folk classification, in geology, is a technical descriptive classification of sedimentary rocks devised by Robert L. Folk, an influential sedimentary petrologist and Professor Emeritus at the University of Texas. Folk's sandstone (clastic) c ...

scheme, mainly in sandstones.

References

*Folk, R.L., 1974, Petrology of Sedimentary Rocks: Austin, TX, Hemphill Press, second edition, 182 p. Petrology {{petrology-stub

See also

References