ABSTRACT
COAL AND OIL (including natural gas) are the two principal fossil fuels found in sedi - mentary rocks and, currently, the world’s dominant source of commercial energy. They have close parallels in their origin but significant differences in occurrence. Whereas coal is a common sedimentary rock, oil is a liquid fuel that is hosted or reservoired in sediments. They are also closely linked in that coal is an important source rock for gas and, in some cases, for oil too. Coal is the main focus of this chapter, but the origin and occurrence of oil is also described briefly.
