Arkell.1956.Jurassic..

CALLOVIAN
NORTHERN SINAI 291
A great thickness (perhaps 500 m.) of shales, marls and limestones is
grouped together in the descriptions as Bathonian - Callovian, not
separated. The only Callovian ammonites, however, are a Reineckeia
anceps, a 'Stepheoceras' [Erymnoceras] and an impression of Quenstedtoceras
recorded by Couyat-Barthoux & H. Douville in their preliminary paper
(1913, p. 267) and repeated by Hume & others (1921, p. 341), but not
mentioned in H. Douville's monograph. Probably these records were
based on species of Bajocian Ermoceras and silently corrected by Douville
in his monograph. Hoppe's (1922) unfigured Reineckeiae are equally
suspect, in view of the strong resemblance to Reineckeiae shown by various
Bajocian Ermoceras since found in Arabia.
BATHONIAN
The bulk if not all of the 500 m. of so-called Bathonian-Callovian beds
are probably Upper and Middle Bathonian. They contain large numbers
of Eligmus rollandi, Gryphaea costellata and Eudesia cardium. The only
two ammonites figured by Douville from these beds are Bathonian,
namely Micromphalites pustuliferus (Douville, 1916, pi. vi, figs. 2, 3)
(Middle Bathonian) and Clydoniceras orientale (Douville, pi. vi, fig. 1)
(Upper Bathonian). The association of Eligmus and Eudesia is reminiscent
of the Upper Bathonian ('Bradfordian') of Normandy.
UPPER BAJOCIAN
Underlying a 3 m. Bathonian bed with Clydoniceras and Oecotraustes,
the Standard Oil Company geologists measured 275 m. of beds without
ammonites, and then 148 m. with an Upper Bajocian assemblage containing
the celebrated Ermoceras and Thamboceras fauna, known nowhere else in
the world until discovered in 1948-51 in central Arabia. The associated
ammonites, which at Maghara include Oppelia cf. subradiata (Sow.),
Lissoceras oolithicum (d'Orb.), Spiroceras bifurcati (Quenst.), and Leptosphinctes
cf. tenuiplicatus (Brauns) with Phylloceratids and Lytoceratids,
proclaim an early-Upper Bajocian date, not later than Garantiana Zone.
MIDDLE BAJOCIAN AND EARLIER
From between 95 m. and 115 m. below the lowest Ermoceras bed was
collected a good specimen of Normannites cf. braikenridgei (Sow.), which
indicates the Sauzei Zone. Below this were measured no less than 558 m.
of beds (mostly sandstones) without ammonites, then a 9 m. bed from
which was obtained a crushed fragment which could belong to a flat
Sonninia of the style of S. dominans Buckman or to a Grammoceras
cf. muelleri (Denckmann) (topmost Jurense Zone). At base were
252 m. without ammonites to the bottom of the section. (See Arkell,
1952, p. 307.)
http://jurassic.ru/