The Ichnofacies Paradigm - Trace Fossils as Indicators of Sedimentary Environments - page 99

Chapter 4
The Ichnofacies Paradigm
James A. MacEachern, * ,1 Kerrie L. Bann, † Murray K. Gingras, ‡
John-Paul Zonneveld, ‡ Shahin E. Dashtgard * and S. George Pemberton ‡
*ARISE, Department of Earth Sciences, SimonFraserUniversity, Burnaby, BritishColumbia, Canada,
† Ichnofacies Analysis Inc., Calgary, Alberta, Canada, ‡ IRG, Department of Earth and Atmospheric
Sciences, University of Alberta, Edmonton, Alberta, Canada
1 Corresponding author: e-mail: [e-mail]
1. INTRODUCTION
The ichnofacies paradigm has evolved across a nearly six-decade period since
its original inception ( Seilacher, 1953a,b ). Today, the ichnofacies paradigm
stands as a multidimensional framework that is underpinned by recurring,
facies-controlled (i.e., environmentally related) groupings of biogenic struc-
tures that reflect animal responses (ethology) to paleoenvironmental conditions
(see Buatois and M´ngano, 2011; MacEachern et al., 2007a,b for summaries).
As such, ichnofacies provide a logical first step in the interpretation of deposi-
tional settings and constitute a crucial component in the analysis of infaunal
behavioral diversity in different environmental settings.
1.1 Rise of the Ichnofacies Concept
The concept of “ichnofacies” was developed by Dolf Seilacher in the 1950s and
1960s ( Seilacher, 1953a,b, 1964 ), primarily focussed onmarine successions. The
concept was originally based on empirical observation of recurring associations
of trace fossils coupled with the recognition that the parameters controlling the
distribution of marine tracemakers tend to change with increasing distance from
the paleocoast. In response to a highly influential paper in a theme volume dedi-
cated to discerning paleobathymetry ( Seilacher, 1967 ), trace fossils within the
“Seilacherian” ichnofacies framework were soon (albeit erroneously) regarded
as paleobathymeters (e.g., Farrow, 1966; Pickett et al., 1971; Weimer and Hoyt,
1964 ). While ichnofacies remain essential to paleoenvironmental reconstruc-
tions, paleobathymetry constitutes only one aspect of the modern concept and
is largely confined to marine associations. Organism behaviors (ethology) and
their resulting biogenic structures in subaqueous regimes are principally con-
trolled by factors including substrate consistency, sediment grain size, energy