Page 188 - Sedimentology and Stratigraphy

Trace Fossils 175

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Fig. 11.12 Assemblages of trace fossil forms and their relationship to the major divisions of the marine realm. (Adapted
from Pemberton et al. 1992.) The assemblages are named after characteristic ichnofauna and the ‘type’ ichnofossil does not
need to be present in the assemblage.

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Fig. 11.13 The characteristics of trace
fossils are influenced by the nature of
the substrate. Boring organisms cut
sharp-sided traces into solid rock or
cemented sea floors (hardgrounds).
Semiconsolidated surfaces (firm-
grounds) result in well-defined burrows.