الفهرس 
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Abstract
This study deals with the stratigraphy, paleontological studies of bivalves,
gastropods and echinoids as well as foraminiferal content, paleoecological
investigations and the geographic distribution of the studied fauna from the
Cretaceous sequence of Gebel El-Minsherah and Gebel El-Hamra,North Sinai,
Egypt.
The studied Cretaceous sequence could be subdivided lithostratigraphicallyinto
five lithostratigraphic units arranged from base to top as follows:
I. Mallia Formation (Early Cretaceous)
II.Raha Formation (Cenomanian)
m.Wata Formation (Turonian)
IV.Themed Formation (Coniacian-Santonian)
V.Sudr Chalk (Campanian-Maastrichtian)
The paleontological investigations led to the recognition of 128 species of
macrofossils . Among them 59 bivalve species belonging to 37 genera, 26 families,
8 orders and 5 subclasses . Twenty gastropod species belongingto 15 genera, 13
families, 3 orders all of them belongingto the subclass prosobranchia. Forty nine
echinoid species (23 regular and 26 irregular) belonging to 23 genera, 15 families
and 10 orders. Two echinoid species are considered new: Loriolia paucimuiarta
from the Cenomanian of Gebel El-Hamra and Rachiosoma geysi from the Turonian
of Gebel El-Minsherah . One subspecies (Previously described as a mutation) is
introduced; Hemiaster heberti turonensis. Three species, which are known from
elsewhere, recorded for the first time from Egypt: Heterodiadema buhaysensis
(from the Maastrichtian of United Arab Emirates-Oman border), Phymosoma
cenoman ensis, Phymosoma sulcatum (from the Cenomanian and Santonian of
France respectively.
II.Gyrostrea delettrei - Ceratostreon flabellatum- Neolobites fourtaui zone.
IIIMaghrebellaforgemoli - Hemiaster cubicus horizon.
IV.Costagyra olisiponensis -llymatogyra africana horizon.
Turonian:
LAmmonites horizon.
II.Hemiaster heberti turonensis horizon.
III.Phymosoma abbatei horizon.
Coniacian-Santonian:
IV.Oscillopha dichotoma- Plicatula ferryi horizon.
These zones and horizons were correlated together and with other zones proposed
by other authors inside Egypt.
Fifty foraminiferal species (35 benthonic and 15 planktonic) were identified. These
foraminiferal species led to the construction of five zones in Gebel El-Minsherah
and four zones in Gebel El-Hamra .
The biostratigraphic zones of Gebel El-Minsherah are arranged from base to top as
follows:
Cenomanian:
I. Nezzazata simplex zone.
II. Orbitolina cf. concava zone.
III. Biconcava bentori- Nezzazata gyra zone.
Turonian:
IV. Discorbis turonicus- Nezzazatinella aegyptiaca zone.
Coniacian-Santonian:
V. Dicarinella concavata equivalent zone.
The biostratigraphic zones of Gebel El-Hamra are arranged from base to top as
follows:
Cenomanian:
1. Orbitolina cf. concava zone.
II. Agglutinated foraminiferal zone.
m. Flabellammina aegyptiaca-Flabellammina alexanderi zone.
Turonian-Santonian
IV. Discorbis turonicus zone.
These zones were correlated together, and also with the prementioned macrofossils
zones and horizons, besides they were correlated with some related zones proposed
by other authors inside Egypt.
The paleoecological investigations led to the following results:
1- The Cenomanian was deposited under shallow, warm, normal salinity marine
conditions of the outer-shelf (less than 50 m).
2- The Lower Cenomanian of Gebel El-Minsherah was deposited in extremely
shallow, near-shore marine conditions.
3- The depositional environment of Gebel El-Hamra during the Cenomanian was
shallower and relatively lower in salinity than in Gebel El-Minsherah .
4- The Turonian was deposited in shallow water of the middle-shelf (50-1 OOm)in
both studied sections.
5- The Coniacian-Santonian of Gebel El-Minsherah was deposited under open
marine conditions most probably in the inner-shelf (100-200m), while that of Gebel
EI-Hamra was deposited at relatively shallower, highly agitated marine environment
(less than 100 m).
The paleobiogeographic distribution of the studied fauna indicates that they
show Tethyan affinity; strong affinity to North Africa, West Europe and the Middle
East. They show a limited affinity to West Africa, South Northern America and
North Southern America, finally it confirms the hypothesis of Furon (1935) and
others of a Trans-Saharan Seaway.