Siltstone is primarily formed from what size of particles?

Siltstone is a type of sedimentary rock that is primarily composed of silt-sized particles. These particles are generally between 1/16 mm and 1/256 mm in diameter. Siltstone is formed from the accumulation and lithification of these fine particles, which are typically too small to be seen individually without the aid of a microscope. The characteristics of siltstone, such as its smooth texture and low porosity, directly relate to the size of the particles that comprise it.

In contrast, sand-sized particles contribute to the formation of sandstone, cobbles are associated with conglomerates, and gravel-sized particles are linked to sedimentary rocks like breccia. Understanding the particle size distribution is essential in identifying and classifying sedimentary rocks, and recognizing that siltstone specifically originates from silt-sized particles is crucial for students studying geology or related fields.