biostratigraphy and paleoecology of cretaceous/tertiary boundary in ...

Chapter Three Biostratigraphy
Silva and Sliter, 1995, 1999) from Italy. (Abdel-Kareem & Samir. 1995), Egypt.
(Fig. 3.12)
The Pseudotextularia intermedia Zone spans about 0.73Myr (69.06-
68.33Ma), (730Ky/19) meters estimating absolute ages based on magnetochron
ages with (38.5 Ky/meter) of moderate rate of deposition (Fig.3. 12 – 3. 13),
(Fig,5.11)
Age: Late Early Maastrichtian.
Note: it is important to mention that the Pseudotextularia intermedia Zone was
recorded also from the other studied sections (only the upper part) in which the
lower limit not studied. This biozone represented by moderate diversity of
planktonic foraminiferal assemblage by 43 species in Sirwan section, (Fig.3.1),
44 species in Qulka section (Fig.3.5) and Low diversity planktonic foraminiferal
assemblage by (27) species in Qishlagh section, (Fig.3.4)
3.2.1.5- Racemiguembelina fructicosa Interval Zone (CF4)
Racemiguembelina fructicosa zone (CF4) was introduced by Li and Keller
(1998 a and b) as a biostratigraphic interval between FAD of Racemiguembelina
fructicosa (Egger) at the base and the FAD of Pseudoguembelina hariaensis at
the top. The FAD of Racemiguembelina fructicosa (Egger) in the studied section
recorded from the upper most part of reddish to pale brown unit and covers the
basal part of the Tanjero Formation (sample no.38) to the FAD of
Pseudoguembelina hariaensis Nederbragt within Tanjero Formation (sample
no.58). (plate. 1, Fig. 9). Attaining a thickness of 23m. at Gali section (Fig 3.7)
110 meters Sirwan section (Fig 3.1) 32 meters Kato section (Fig 3.3) 83 meters
Qulka section (Fig 3.5), while the upper limit of this zone in Qishlagh section not
recorded due to change of environmental parameters which is represented by
thick bedded interfingering limestone of Aqra Formation at the upper part of
Tanjero Formation
It is important to mention that the zonal scheme of Cretaceous foraminifera
(CF) proposed by Li and Keller (1998 a&b), which replaces the Abathomphalus
mayaroensis zone with four zones (R. fructicosa zone, P. hariaensis Zone, P.
palpebra Zone, P. hantkeninoides Zone), for a much improved age estimate for
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