Fluvial Environments - Trace Fossils as Indicators of Sedimentary Environments - page 318

Chapter 12
Fluvial Environments
Ricardo N. Melchor, * ,1 Jorge F. Genise, † Luis A. Buatois ‡ and
Aldo M. Umazano }
*INCITAP (CONICET and Universidad Nacional de La Pampa), Santa Rosa, La Pampa, Argentina,
† CONICET, Divisio´n Icnologı´a, Museo Argentino de Ciencias Naturales, Buenos Aires, Argentina,
‡ Department of Geological Sciences, University of Saskatchewan, Saskatoon, Canada,
} Universidad Nacional de La Pampa, Santa Rosa, La Pampa, Argentina
1 Corresponding author: e-mail: [e-mail]
1. INTRODUCTION
The number of studies on the ichnology of fluvial deposits has increased signifi-
cantly since the early 1980s. Trace fossils in fluvial deposits were considered
undiagnostic and their distribution as not related to any particular environment
(e.g., Picard and High, 1973 ). These earlier studies have been influenced by the
notion of the Scoyenia Ichnofacies as being broadly defined and undistinctive
( Seilacher, 1977 ). Also, it has been argued that the Scoyenia Ichnofacies reflects
a community of organisms of low diversity, the preservation potential of which
is very low ( Ekdale et al., 1984 ). In the past decades, many studies have been
directed toward the revision and redefinition of the Scoyenia Ichnofacies and to
distinguish it from other associated archetypal trace-fossil assemblages that
may occur in fluvial and other continental deposits ( Buatois and M´ngano,
1995, 1998; Frey et al., 1984; Genise et al., 2000, 2010 ). The possibility of rec-
ognizing continental ichnofacies and the ichnofacies concept itself have been
questioned ( Goldring, 1993; Hasiotis, 2004 ), although ichnofacies are well esta-
blished and of common usage ( Bromley et al., 2007; MacEachern et al., 2007 ).
The biological literature on the burrowing and nesting behavior and descrip-
tion of modern structures of arthropods and other organisms associated with
fluvial environments is fairly large, but until recently such studies have not been
formally incorporated within the background of ichnology. Relatively few con-
tributions on traces from fluvial environments within the conceptual framework
of ichnology exist ( De, 2002; Laporte and Behrensmeyer, 1980; Lawfield and
Pickerill, 2006; M ´ ngano et al., 1996; Martin, 2009; Melchor et al., 2010; Pryor,
1967; Ratcliffe and Fagerstrom, 1980; Smith and Heim, 1971 ). The diversity of
trace fossils that can be found in fluvial environments is reasonably large, and
they can potentially contribute to the diagnosis of the paleoenvironment