Key Words: GEOLOGY UNIT 5.1

Organism - something that was once alive. May be single cell or multicellular (many cells)

Body fossils - the hard parts of an organism like the skeleton or shell

Dissolution - process whereby minerals that make up the fossils are dissolved away and removed in solution by groundwater

Replacement - atom by atom substitution of one mineral for another

Mould - the impression of the outside or inside of a fossil

Cast - an infilled fossil void, usually with another mineral

Anaerobic - without oxygen

Anoxic - water without oxygen

Ichnology - the study of trace fossils

Trace fossils - preservations of the activity of an organism regarded as fossil behaviour. Include tracks, trails, burrows, borings and excrement

Bioturbation - refers to burrowing or working the sediment in a way that disrupts bedding caused by the activity of living organisms

         Modes of life

Benthonic - an organism living on or in the sediment substrate of the sea floor

  Position:

Infaunal - an…