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Chapter 14
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The Sequence
Stratigraphic Significance of Trace Fossils: Examples from the Cretaceous
Foreland Basin of Alberta, Canada
S. George Pemberton
James A. MacEachern
Department of Geology
University of Alberta
Edmonton, Alberta, Canada
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ABSTRACT
Trace fossils represent both sedimentologic
and paleontologic entities and, as such, represent a unique blending of
potential environmental indicators in the rock record. Trace fossils and
trace-fossil suites can be employed effectively to aid in the recognition
of various types of discontinuities and to assist in their genetic interpretation.
Ichnology may be employed to resolve surfaces of sequence stratigraphic
significance in two main ways: (1) through the recognition of substrate-controlled
ichnofacies, which mark time gaps between the original deposition of a
unit (with or without softground burrowing) and later superimposition of
a postdepositional trace-fossil assemblage, and (2) through careful analysis
of vertical ichnological successions (analogous to facies successions).
Integrating the data derived from substrate-controlled ichnofacies with
data from vertical ichnological successions provides a powerful tool for
the recognition and interpretation of important sequence stratigraphic
surfaces. |
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