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

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.