The classification of detrital sedimentary rocks is an important part of understanding the geology of a region. Detrital sedimentary rocks are classified by their grain size, whether they contain fossils, and other factors. This article will discuss how these types of rocks are classified, and give you some examples so you can better understand them! -Grain Size: The grain size ranges from coarse to fine sand or silt particles in various sizes that fill spaces between larger solid grains such as pebbles or gravel in clastic sediments. Coarse grained material has large pieces with flat surfaces whereas fine grained material has small particles with rounded shapes which fills all available space within clasts (or fragments) like tiny pebbles or sand. -Fossils: Fossils are the remains of organisms that lived in ancient times and were preserved by being buried under sedimentary deposits, -such as mudflows, glaciers, atolls, or other natural events such as earthquakes. Detrital sediments containing fossils provide important clues to Earth’s geologic history because they can be dated precisely according to their type – for example through radiometric dating techniques like uranium series disequilibrium. -Other Factors: Other factors include color (black), texture (fine grained) and hardness (soft rocks). These properties often change abruptly when rock types meet between different detrital packages so it is very important to know what you’re looking at!