Trace fossils occupy a large proportion of this bedding plane.
The Droser-Bottjer ichnofabric index is a method used to quantify the degree of bioturbation in a sedimentary rock. It involves grading the amount of trace fossil activity on a scale of 1–6; a value of 1 indicates that bioturbation is entirely absent, whereas the highest grade would involve a bedding plane containing over 60% trace fossil cover.[1] This index can be applied in either a vertical or horizontal aspect. The vertical component provides an indication of the interplay between physical and chemical aspects of the environment and the degree of biological activity.[2] The vertical ichnofossil index is harder to measure; it involves quantifying the amount of disturbance to the original sedimentary fabric.[3]
References
^Barras, C. G.; Twitchett, R. J. (2007). "Response of the marine infauna to Triassic–Jurassic environmental change: Ichnological data from southern England". Palaeogeography, Palaeoclimatology, Palaeoecology. 244 (1–4): 223–241. Bibcode:2007PPP...244..223B. doi:10.1016/j.palaeo.2006.06.040.