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individually distinguishable burrows, sometimes referred to as “bioturbate
texture” ( Frey, 1973 ).
The role of ichnofabric analysis in understanding paleo-oxygen conditions
within the sediment has been explored and outlined by a large number of
workers ( Bromley and Ekdale, 1984a; Ekdale, 1985b; Ekdale and Mason,
1988; Leszczy´ski, 1991; Savrda and Bottjer, 1986, 1989a,b, 1994; Savrda
and Ozalas, 1993; Wignall, 1991, 1993 ). This application of ichnofabric re-
cognition is very important for several reasons, including the enhancement of
our understanding of paleoecological adaptations of certain benthic organ-
isms to low-oxygen environments, tectonic development of silled marine
basins, and generation and accumulation of hydrocarbons in organic-rich sedi-
mentary units. Currently, there is a strong economic emphasis on exploration
for unconventional hydrocarbon resources in black shale strata, which fre-
quently exhibit characteristic, Chondrites -dominated, oxygen-influenced
ichnofabrics ( Bromley and Ekdale, 1984a; Savrda and Bottjer, 1989a;
Schieber, 2003 ).
Trace-fossil taphonomy contributes to the development of ichnofabrics.
Bromley and Ekdale (1984b, 1986a,b) recognized the role of ichnofabric in
influencing the early diagenetic preservation of trace fossils, particularly in
the case of burrow flints in pelagic chalk deposits ( Bromley and Ekdale,
1984b, 1986a ) and also in early stage pressure-solution seams in fine-grained
carbonates ( Ekdale and Bromley, 1988 ).
In 1990, Pollard and Ekdale convened the first international symposium
with ichnofabric as the focal point at the International Sedimentological Con-
gress in Nottingham, England ( Ekdale and Pollard, 1991 ). Participants pre-
sented a diverse array of seminal ideas of how ichnofabric approaches can
aid in describing the biogenic aspects of various sedimentological situations
and solving particular sedimentological problems. A dedicated theme issue
dealing with ichnofabrics in the journal Palaios (1991, volume 6, number 3)
stemmed directly from this symposium. Several papers in this issue expanded
upon the description of local ichnofabrics to demonstrate their use in regional
studies, such as in stratigraphic correlation ( Mortimore and Pomerol, 1991 ),
basin dynamics ( Droser and Bottjer, 1991 ), and petroleum exploration
( Bockelie, 1991 ).
Also as a result of the symposium in Nottingham, an ongoing series of Inter-
national Ichnofabric Workshops (IIW) was initiated in order to bring together
diverse views for advancement of ichnofabric investigations. The 1st IIW was
held in Norway in 1991, the 2nd in the United States (Utah) in 1993, the 3rd in
Denmark in 1995, the 4th in the Bahamas in 1997, the 5th in England in 1999,
the 6th in Venezuela in 2001, the 7th in Switzerland in 2003, the 8th in New
Zealand in 2005, the 9th in Canada in 2007, the 10th in China in 2009, and
the 11th in Spain in 2011. These workshops have grown steadily in size and
diversity over time, and all indications are that they will continue on a regular
basis for many years to come.
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