Characteristics

Siltstone is a fine grained clastic sedimentary rock and composed of silt-sized particles. It forms in silt deposits where silt-particles are cemented into a rock. Silt-size particles can be found close to mud and sand deposits. It is the intermediate level of size between sand and mud.

The most common environments in which is formed are therefor: fluvial, aeolian, tidal, coastal, lacustrine, deltaic, glacial, paludal and shelf environments. Sedimentary structures such as layering, cross-bedding, ripple marks, erosional contacts, and fossils provide evidence of these environments. [1]

Siltstone has usually a gray, brown or reddish brown color with a white streak. It can vary from this color by weathering or due to a composition of the cement this can give a various amount of extra colors. Siltstone is composed of quartz and clay minerals and due to these composition it has an hardness of 6.5 on the Mohr scale.

References

• https://geology.com/
• https://geologyscience.com/