Course: Science Subtest I
Lesson: Earth's Resources
Topic: Fossil Fuels III: Coal      Page 8 of 18  

Coal is found under layers of sedimentary rock such as limestone and shale, and over sandstone. Geologists deduce that the swampy places where the plant material for coal originated were later overlain by oceans. Sedimentary rocks built up over the coal-forming beds as sand and clay particles settled out of the ocean water.