The Glossifungites Ichnofacies and Sequence Stratigraphic Analysis: A Case Study from Middle to Upper Eocene Successions in Fayum, Egypt

ABSTRACT

The Glossifungites Ichnofacies was erected by Dolf Seilacher (the father of modern ichnology) in the mid-nineteen sixties to encompass burrows excavated into firm or compacted substrates. Correspondingly, this firmground ichnofacies has been used extensively in the identification of omission surfaces and the identification and interpretation of sequence stratigraphic discontinuities. A case study from Eocene strata in the Fayum depression of Egypt presents an opportunity to showcase a genetic approach for classifying occurrences of the Glossifungites Ichnofacies. More than twenty-five Glossifungites Ichnofacies–demarcated surfaces are documented and examined in this study. Based on the origin and character of these discontinuities, the examined surfaces are grouped into two main types: those of autogenic origin and those of allogenic derivation. The allogenically generated expressions of the Glossifungites Ichnofacies are associated with key-stratigraphic discontinuities of sequence stratigraphic significance and are the most common in the Eocene succession. Such surfaces are attributed, herein, to transgressively modified sequence-bounding discontinuities (FS/SU), systems tract-bounding surfaces (maximum flooding surfaces, MFS, and transgressive surfaces, TS), and finally parasequence-bounding surfaces (flooding surfaces, FS). These Glossifungites Ichnofacies-demarcated surfaces have proven to be crucial in the sequence stratigraphic interpretation of the middle to upper Eocene succession in the Fayum depression.

KEYWORDS:

• Glossifungites
• Sequence stratigraphy
• Middle-Upper Eocene
• Fayum
• Egypt

Acknowledgments

We thank the Egyptian Environmental Affairs Agency EEAA for assistance in obtaining fieldwork permits. Thanks are also due to our colleagues in the Ichnology Research Group (IRG) at the University of Alberta for their continual help and fruitful discussions. The authors would like to thank the Natural Sciences and Engineering Council of Canada for Discovery Grants awarded to M.K. Gingras, S.G. Pemberton, and J.A. MacEachern that helped fund this research. SGP also acknowledges funding received for his position as the Canada Research Chair in Petroleum Geology. Additional funding from Dr. Fred Wehr and Apache Egypt is gratefully acknowledged. We extend our thanks to the two anonymous reviewers who helped strengthen the final manuscript.

Funding

We would like to thank the Higher Education and Scientific Research Ministry, Egyptian Government, for funding support for the first author.