 Organism dies.  Organism is buried in sediment.  Soft parts decay.  Hard parts dissolve.  An impression or mold forms when the sediment hardens.  Sediment fills the mold and hardens forming a cast or original model of the organism.

 Mold is the imprint or impression.  Cast is the model or fossil formed from sediment or minerals.

 Whole Body – animals entire body is trapped in a swamp, tree sap or is frozen.  Usual formation – animal dies, buried, soft parts decay – fish.  Impression – mold and cast.

 Less likely to fossilize: › Soft body parts – decay › Land – scavengers and weathering › Energy in environment high like a fast moving river  More likely to fossilize: › Hard parts like bones › Water easily buried › Calm environment

 An energy-rich resource formed from the buried remains of a once-living organism

 Energy is stored in the cells of the dead organism.

 The process of photosynthesis created the energy.  Plants and protists produce energy through photosynthesis.  Animals eat plants and other animals that store this energy.

PetroleumSimilaritiesDifferences Ocean Animal - ProtistOrganism diesSwamp Plants OceansOrganism is buriedLands Decay Temperature and Pressure Increase

 Pennsylvania was once covered by swamps.