The Sedimentological Significance of Trace Fossils

The marine tube-building polychaete, Owenia fusiformis, selects sand grains of tablet form for its tube. It can concentrate the mineral hornblende at least 25-fold and these concentrations may persist after the death of the worm. Owenia and a small anemone, Zaolutus actius, can act together to stabilize the sand surface against movement by wave surge. The result is the formation of an area of stabilized substrate, with which characteristic animals and plants are associated, in the midst of a region of shifting granular substrate.