- Ichnofacies
An ichnofacies is an assemblage of
trace fossil s that provide an indication of the conditions that their formative organisms inhabited.The concept
Trace fossil assemblages are far from random; the range of fossils recorded in association is constrained by the environment in which the trace-making organisms dwelt. Palaeontologist
Adolf Seilacher pioneered the concept of ichnofacies, whereby the state of a sedimentary system at its time of deposition could be implied by noting the fossils in association with one another.cite journal
author = Seilacher, A.
year = 1967
title = Bathymetry of trace fossils
journal = Marine Geology
volume = 5
issue = 5-6
doi = 10.1016/0025-3227(67)90051-5
pages = 413-428
issn = 0025-3227]Their power
Ichnofacies can provide information about water depth,
salinity ,turbidity and energy.In general, traces found in shallower water are vertical, those in deeper water are more horizontal and patterned. This is because of the abundance of suspended food particles, such as plankton, in the shallower waters of the photic zone. In deeper waters, there is a necessary transition to sediment feeding - extracting nutrients from the mud. Food availability, hence trace type, is also controlled by energy - high energy environments keep food particles suspended, whereas in lower energy areas, food settles out evenly, and burrows will tend to spread out to cover as much area as economically as possible.
Ichnofacies have a major advantage over using body fossils to gauge the same factors; body fossils can be transported, but trace fossils are always "in situ".
Recognised ichnofacies
References
External links
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