GSA Annual Meeting in Denver, Colorado, USA - 2016

Paper No. 125-8
Presentation Time: 3:35 PM


GINGRAS, Murray, Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada and HARRIS, Nicholas, Earth and Atmospheric Sciences, University of Alberta, Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, T6G2E3, Canada,

This paper sets out a philosophical approach to ichnological (trace fossil) analysis, in fine-grained sedimentary media, which focuses on the interpretation of trace fossils as sedimentary structures rather than as paleontological entities per se.

Using wide-ranging datasets and a large number of observations and interpretations, a “Process Ichnology” framework for fine-grained strata is proposed. This interpretive framework provides an improved means of estimating the presence and magnitude of various physical and chemical (i.e., physico-chemical) depositional stresses (e.g., water turbidity, sedimentation rates, substrate consistency, salinity, and oxygenation) in ancient sedimentary environments.

Ichnological datasets that are considered include: 1) trace-fossil distributions; 2) ethological diversity and the range of diversity; 3) the presence or absence of burrow linings; 4) trace-fossil size; and, where observable, 5) postdepositional compaction of trace fossils. From these data, higher-resolution estimates can potentially be made for the determination of sedimentation rates, temporal variation in sedimentation rate, sediment consistency, and aspects of the bottom- and interstitial-water chemistries.

The methodologies and interpretations herein are intended for use by non-ichnologists in a manner akin to the interpretation of physical sedimentary structures. However, the outlined framework is complementary to other methods of ichnological analysis, such as ichnofacies- or ichnofabric-analysis, and can be applied as such.