Shallow-Marine Carbonates - Trace Fossils as Indicators of Sedimentary Environments - page 682

and Ekdale, 1999; El-Asa'ad, 1987; Gaillard et al., 1994; Giannetti and Monaco,
2004; Goldring et al., 2005; Monaco, 1995; Monaco and Garassino, 2001;
Monaco and Giannetti, 2002; Ol´riz and Rodr´guez-Tovar, 2002; Schweigert,
1998; Wilson and Palmer, 1994 ). In contrast, Cretaceous carbonates are scarcely
dealt with in ichnological-paleoenvironmental studies (e.g., Husinec and Read,
2011; M´ngano and Buatois, 1991; Mezga et al., 2006; Moro et al., 2007; Petti
et al., 2008 ). The Cenozoic again is covered by numerous studies dealing with
various environments and topics (e.g., Braithwaite and Talbot, 1972; Cunning-
ham et al., 2009; Curran, 1984, 1994, 2007; Curran and Martin, 2003; Curran
and White, 1991; de Gibert and Goldring, 2007; Farrow, 1971; Garrett, 1977;
Lukasik and James, 2003; Massari and D'Alessandro, 2010; Pedley, 1992; Shinn,
1968; Tedesco and Wanless, 1991 ).
Following their main morphological characteristics, carbonate systems can
broadly be classified into rimmed carbonate shelf, carbonate ramp (homoclinal
and distally steepened), and isolated platform ( Read, 1985 ). Each system has a
different position for the carbonate factory and sediment transport pathways,
giving reason to the classification into T factory (tropical), C factory (cool-
water), and M factory (mud-mound) ( Schlager, 2005 ).
2. ICHNOLOGICAL CHARACTERISTICS OF
SHALLOW-MARINE CARBONATE SYSTEMS
The presence, distribution, and quality of trace fossils in shallow-marine car-
bonates are controlled by a number of criteria which can be grouped into three
major categories ( Table 1 ): (1) the faunal composition and distribution of ben-
thic organisms as potential tracemakers, (2) the sediment type and its alteration,
and (3) the early-diagenetic history. The interaction of these three criteria can
create and convey a specific trace-fossil record which represents only a fraction
of the full range of possible outcomes. According to which category played the
most important role in the fossilization process, distinct ichnofaunas and trace-
fossil associations may represent the same paleoenvironment in different set-
tings. To facilitate evaluation of the trace-fossil record and to employ it for
interpretation of paleoenvironments, each category is discussed in more detail
before turning to characteristic ichnofacies of shallow-marine carbonates.
2.1 The Composition and Distribution of Benthic Organisms
The location of a given carbonate depositional system in relation to the equator is
an important factor controlling its development and the fauna available for modi-
fication of the sediment. Warm waters of tropical systems generally contain a
higher diversity of organisms than non-tropical, cool-water systems, which
may have an effect on the kind and the amount of substrate modification that
can occur. Most trace-fossil forms occur in both carbonate and siliciclastic envi-
ronments, with only a few exceptions of carbonate-specific ichnotaxa that result