A semiquantitative field classification of ichnofabric

In order to document variations in the extent of bioturbation recorded in the stratigraphic record, we have designed a semiquantitative field classification of ichnofabric ("all aspects of the texture and internal structure of a sediment that result from bioturhation'; Ekdale et al. 1984) based on pattern recognition of the percentage of original sedimentary fabric which has been disrupted by biogenic reworking. Six ichnofabric indexes have been established. When used in conjunction with descriptive ichnology and sedimentological data, this methodology can be used to determine changes in the nature and amount of bioturbation in sedimentary rocks.