For environmental interpretation, biogenic sedimentary structures have the obvious advantage that they are absolutely autochthonous (rare exceptions can be easily recognized) and that they reflect a direct behavioral response to environmental conditions. On the other hand, the palichnological record is largely biased by preservational factors. The majority of the biogenic traces that we observe in present-day environments, particularly the exichnial ones--those on the upper surface of a bed (Martinsson, 1970; Chapter 1, Table 2) -- may have an almost zero fossilization potential. We, therefore, consider the study of modern traces as a prerequisite to understanding the origin of individual trace fossils, but our paleoenvironmental classification is based mainly on comparisons between fossil ichnocoenoses; i.e., on the other side of the “f ossilizati barrier”.
Figures & Tables
Trace Fossil Concepts
The advancement of ichnological research has left in its wake a considerable volume of literature that contains many important concepts and the results of some excellent field studies. These notes try to consolidate the most salient topics of the discipline and emphasize the application of ichnological concepts and data to geological problems. In many respects, a detailed knowledge of trace fossil concepts is a matter of experience rather than education. Trace fossils, unlike other fossils, are part of the rock and, thus, they are difficult to collect and curate. As a result, interested geologists must go to the field and see a lot of trace fossils in a variety of different views, preserved under a variety of different conditions, to build a working expertise on such structures. This short course is designed to suit the needs of a diversified audience, which is made up of geologists from both academic and industrial institutions. Although the primary concern is to introduce the subject to those having little background in ichnology, the hope is to also update those geologists who already use trace fossil information in their investigations.