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instance, in the Late Cenozoic Yakataga Formation, Alaska ( Eyles et al., 1992 ),
the Pleistocene of the New Jersey margin ( Savrda et al., 2001 ), and the Late
Cretaceous Tres Pasos Formation of Chile ( Shultz and Hubbard, 2005 ). Slope
examples of the Cruziana Ichnofacies are most common in areas where oxygen
and food are readily distributed to deeper-water settings, such as tectonically
active slopes associated with narrow shelves, areas where seasonal coastal
down-welling of cold waters is significant, glacially influenced slopes, slopes
dominated by strong contour currents, regions where surface-water productivity
is high, and areas proximal to conduits that focus currents and transfer sediment
from the shelf to the basin-floor (e.g., Buck and Bottjer, 1985; Eyles et al., 1992;
Ineson, 1987; Savrda et al., 2001; Shultz and Hubbard, 2005; Wetzel, 2008 ).
3.5 Nereites Ichnofacies
As described above, slope environments are dynamic, commonly characterized
by quiescent conditions interrupted by mass-wasting, strong currents, and
recurring high-energy, erosive sediment-gravity flows in some instances. Owing
to these factors, coupled with a relative abundance of food resources, deposit- and
filter-feeding organisms are expected locally on the slope. Correspondingly,
suites attributable to the Nereites Ichnofacies, and specifically graphoglyptids,
are not widespread in deposits of slope affinity. The Nereites Ichnofacies is com-
mon to settings characterized by continuous yet exceedingly slow rates of sedi-
ment deposition from suspension. These conditions may be interrupted by
periodic out-sized gravity flows, but their frequency must be less than that
required for substrate recolonization by the ambient benthic community. Condi-
tions favorable for trace-fossil suites attributable to the Nereites Ichnofacies are
common to basin-floor depositional environments (e.g., Crimes et al., 1981;
Leszczy´ski and Seilacher, 1991; Uchman, 2001; Uchman and Wetzel, 2011,
2012 ). However, deep-sea drill cores have shown that the ichnofacies is largely
confined to fine-grained substrates that include distal turbidites; it is largely
absent from great expanses of the abyssal plain where sedimentation is more
or less constant and low (e.g., Scholleetal.,1983 ). It is probable that, in many
instances, the lack of lithological variability within slope strata strongly impacts
graphoglyptid preservation ( Seilacher, 1977; Uchman, 2001 ), and where they do
occur, such homogeneity has a negative impact on our ability to recognize them.
Slope settings, where suites attributable to the Nereites Ichnofacies have
been documented, include distal levees associated with large channel systems,
channel-margin deposits, minibasins characterized by regular turbidity current
input, and the channel-lobe transition zone (e.g., Callow et al., 2012a;
Cummings and Hodgson, 2011; Heard and Pickering, 2008; Hubbard and
Shultz, 2008; Kane et al., 2007 ). These environments of deposition are all pre-
sent in close proximity to basin-floor depozones, where the Nereites Ichnofacies
is considered diagnostic ( Seilacher, 1967 ). Unfortunately, previous work has
not focused on the range of BI values, uniformity of burrow distributions,
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