The Campanian-Eocene succession in Gabal Oweina area, Upper Egypt, covering six
rock units (Quseir, Duwi, Dakhla, Tarawan, Esna and Thebes formations) was
revised. The sedimentological and biostratigraphical detailed studies of the succession
helped in reaching a high-resolution sequence stratigraphic classification that led to
the recognition of five third-order depositional sequences and their associated
surfaces and systems tracts. Also, the paleobathymetry deduced from the identified
benthonic faunal assemblages, helped in giving some details about the characteristics
and paleoenvironments of the identified sequences.
The Campanian depositional sequence Dw/DkSQ1, includes both the Duwi and the
lower part of the Dakhla formations, was laid down in a sea oscillating between inner
to middle neritic depths, on shallow subtidal shelf, followed by a shallow inner neritic
depths, on lagoonal environment.
The Maastrichtian depositional sequence DkSQ2 encompass the middle part of the
Dakhla Formation and was laid down in a relatively outer neritic to upper bathyal
depths, on deep subtidal shelf, followed by inner neritic depths, on a shallow subtidal
shelf at the end of the sequence marked by an intraformational conglomerate bed.
The Danian depositional sequence DkSQ3 covers the upper part of the Dakhla
Formation and started by a latest Maastrichtian- earliest Danian hiatus. It
accumulated in gradually deepening waters reaching upper bathyal depths, on deep
subtidal shelf, followed by middle neritic depths, on a shallow subtidal shelf.
The Selandian-Thanetian depositional sequence Dk/T/EsSQ4 comprises the
uppermost part of the Dakhla, Tarawan and the lower part of the Esna formations
and began by Danian-Selandian hiatus. It accumulated in oscillating conditions
between upper bathyal depths, on a deep subtidal shelf to middle neritic depths, on a
shallow subtidal shelf.
The Ypresian depositional sequence EsSQ5 consists of the main parts of the Esna
Formation and initiated by Paleocene/Eocene hiatus. It was laid down in a gradually
deepening sea reaching the deep upper bathyal depths on a deep subtidal shelf, before
reaching shallow middle neritic depths on a shallow subtidal shelf.
Four of the recognized five sequence boundaries (SB1, SB3, SB4 and SB5) coincide
with global sea-level falls, while the other one (SB2) is related to a local tectonic in the
studied area.