Here's a more complete explanation:
* Particle size IS a primary factor: The Wentworth scale, a standard classification system, defines the basic categories of detrital rocks based on grain size:
* Conglomerates: Rounded gravels
* Breccias: Angular gravels
* Sandstones: Sand-sized particles
* Siltstones: Silt-sized particles
* Mudstones/Shales: Clay-sized particles
* Other important factors:
* Composition: The types of minerals and rock fragments making up the sediment are important. For example, a sandstone made of quartz grains will have different properties than one made of feldspar grains.
* Sorting: How well-sorted the particles are (all about the same size, or a wide range of sizes). Well-sorted sediments often indicate a specific environment of deposition.
* Rounding: How rounded or angular the grains are. Rounding occurs during transport, so it can indicate distance traveled by the sediment.
* Texture: Features like bedding, lamination, or cross-bedding provide clues about the depositional environment.
* Cementation: The type of minerals that bind the sediment grains together also influences the rock's properties.
In short, particle size is a crucial starting point for classifying detrital sedimentary rocks, but other factors are essential for a more detailed understanding.
