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

Chapter Three Biostratigraphy
present Plummerita hantkeninoides Zone is equivalent to the upper most part
of Abathomphalus mayaroensis Zone recorded from different parts of the world
(Canudo et al., 1991), (Smit 2005),and (Chacon & Martin-Chivelet 2005) Spain;
(Premoli Silva & Sliter, 1995 & 1999),Italy; (Premoli Silva et al., 1998), eastern
Mediterranean ; (Govindan et al., 1996), India; (Robaszynski et al., 1984, and
Caron, 1985), general; (Maestas et al., 2003), USA, California; (Martinez, 1989;
Luning et al., 1998), south USA. And equivalent to Plummerita reicheli Zone of
(Elnady & Shahin, 2001, and Shahin, 1992,), from Egypt. The present
Plummerita hantkeninoides Zone is equivalent to the Kassbiana falsocalcarata
Zone recorded from Shalki village and Sirwan valley (Kassab et al., 1986),
(Kassab 1976). Tel Hajar.1 (Ghafor 1988), (Figs 3.12-14)
The age estimation of this biozone by (Li and Keller, 1998a), records the
Upper most Late Maastrichtian, with the time span of (65.30Ma) to (65.00Ma),
estimating absolute ages based on magnetochron ages. (300 Ky) estimating
absolute ages based on magnetochron ages with (20 ky/m) high rate of
deposition in Gali section. (23 ky/m) high rate of deposition in Qulka section
Dokan area.(12 ky/m) high rate of sedimentation in Sirwan valley. (Figs. 3.12-14)
Age: Latest Maastrichtian.
It is reliable to pay attention that the decreasing in the number of species
within the Plummerita hantkeninoides Zone is continued to the end of this
zone at K/T boundary as observed in Gali section from (37) to (28) species, (24)
to (20) species in Qulka section and (29) to (23) species in Sirwan section. The
large subtropical high diversities Maastrichtian planktonic foraminiferal
assemblages suddenly disappeared at the stratigraphic level that corresponds to
the top of this biozone. On paleontological criterion the Cretaceous/Tertiary
boundary is placed either at the mass extinctions of Cretaceous planktonic
foraminiferal assemblages as in all studied sections, or at the first occurrence of
Paleocene species. It is convenient to assume that the stratigraphic intervals of
transitional unit (at Tanjero – Red bed contact) in both Qishlagh and Kato
sections in Qala-Cholan and Barzinja area respectively (Figs. 3. 3 - 4), which
located on border line and represent the proximal area of Tanjero basin,
characterized by reworked fossils of different types (macro and microfossils)
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