Coal refers to a sedimentary rock, which is produced in the regions that were once thriving with terrestrial forests with enough water that led to the formation of marshy habitats.
Marine shells are witnessed in the environments of the ocean, that is, mostly the undisturbed deep-sea environment.
Red beads refer to the sedimentary rocks, which are clastic in nature and terrestrial in origin. They are generally made up of sandstones, siltstones, and wackes. It is signified by the presence of red color, which is due to the existence of a high concentration of ferric oxides.
Marine sandstones could be shallow marine or deep marine in origin. Even the coastal environment is appropriate for the generation of marine sandstone.
