During the last AAPG-SEPM meeting, an international group of ichnologists had the opportunity to meet again, this time in Salt Lake City. The reason that brought us together was a one-day symposium on trace fossils and stratigraphy, which was convened by Tony Ekdale (University of Utah). The contributions were in poster format and they included ten papers contributed by authors from six different countries. The scope of the communications included applications of ichnology in biostratigraphy, paleoenvironmental reconstruction, paleoclimatology, sequence stratigraphy and oil geology.

Robert MacNaughton (Queen's University Canada) presented his work (coauthored with Guy Narbonne) on trace fossil biozonation of the Neoproterozoic-Cambrian boundary in the Mackenzie Mountains of Canada. Accurate record of trace fossil occurrences in different facies associations within this interval, allowed the authors to show that the previously recognized biozones are not related to paleoenvironmental changes within the successions.

The influence of climate on the amount of bioturbation was the object of the paper by Gary Galloway and Molly Miller (Vanderbilt University, USA). They compared bioturbation in Triassic fluvial strata in the Colorado Plateau (USA) and Antarctica, using semiquantitative methods (both on bedding planes and vertical exposures). Their preliminary results suggest that high latitude fluvial sandstones are more bioturbated than equivalent low latitude rocks.

Two contributions on marine Jurassic trace fossils from Utah coincided in neighboring panels. Al Curran (Smith College, USA) reported several trace fossil associations from the Carmel Formation in southern Utah and pointed out their similarity with other Jurassic associations in India. Both locations correspond to epicontinental seas in arid climate areas. Kelly Kilbourne and Mark Wilson coauthored this contribution. A related paper by Tony Ekdale and me also dealt with the ichnology of the Carmel Formation, but in central Utah. Our observations revealed several unusual features in the trace fossil assemblages, most remarkably small size of ichnofossils. This allowed us to interpret unfavorable water conditions, most likely hypersaline, for the benthic fauna.

The use of trace fossils in sequence stratigraphy was the topic of three papers. Grant Wach (Texaco, USA) used ichnofacies to characterize depositional settings and sequences of the Black Hawk Formation (Upper Cretaceous) in Utah. A contribution by Sena Reksalegora, Ade Dorojatun, George Pemberton, Phil Lowry and Yohan Kusumanegara (Atlantic Richfield, Indonesia and University of Alberta, Canada) showed how the integration of ichnofacies and sedimentology helped to interpret the depositional environment of Middle Miocene deposits offshore Java and contributed to the characterization of two different type of petroleum reservoirs. Daniel Poiré and Luís Spaletti (Centro de Investigaciones Geológicas, Argentina) reported shallowing-upward stacked sequences in fully bioturbated Upper Cretaceous-Lower Tertiary strata in Patagonia (Argentina) characterized by the succession of trace fossils.

Ron Morris and Richard Behl (California Sate University, USA) presented a paper on the use of X-ray computed tomography in sediment cores offshore of California. This approach allowed them to describe variations in the orientation of burrows that they interpreted as related to variations in water oxygenation. Another paper presented by Fredrick Bockelie (Norsk Hydro, Norway), coauthored with Arild Eldoy, Kjetil Gran and Francisco Porturas, was devoted to the use of borehole images for ichnofacies recognition. The authors compared borehole images with ichnofabrics in actual cores to develop a technique that could result in a more continuous record of ichnofabrics in boreholes.

Arjun Keswani and George Pemberton (University of Alberta, Canada) presented a conceptual model for description and interpretation of bioturbation and related diagenetic processes in dolomites.

In addition to the poster session, an oral technical session presided by Carlton Brett and Tony Ekdale on "Marine Ichnology and Taphonomy" included four trace fossil contributions. Murray Gingras, Ed Clifton, Tom Saunders, and George Pemberton (University of Alberta, Canada) reported the effect of salinity and substrate texture in lateral variations of ichnofacies in Willapa Bay, an estuary on the coast of Washington (United States). Their observations will help to obtain a better understanding of fossil estuarine-filled incised fluvial systems. A paper presented by Jason Lavigne (University of Alberta, Canada) and coauthored by Murray Gingras, George Pemberton and David Eberth, revisited the Teredolites ichnofacies and pointed out the difference between loggrounds and woodgrounds. Their contribution was complemented by the presentation of Elizabeth Heise (Texas A&M University, USA) on the preservation potential of wood in recent marine carbonate environments. Finally, Jordi Martinell, Rosa Domènech and I reported boring assemblages in the Pliocene of the Mediterranean area, and we discussed their utility in recording transgressive surfaces and maximum sea-level positions.

Adding to the ichnological content of the meeting, Al Curran and Bryan White (Smith College, USA) presented an ichnological paper within the technical session on "Modern and Ancient Eolianites". They reported their most recently observations on trace fossils in the Quaternary eolianites in the Bahamas, which some of us had the opportunity to see in situ during the last international ichnofabric workshop.

In conclusion, ichnologists were pretty busy during this last AAPG-SEPM meeting. The contributions were interesting and in some cases quite innovative. Most important of all, we had the opportunity to meet again, discuss our own research, and interchange novel ideas.

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