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

Chapter Three Biostratigraphy
characterized by similar sediment constituent between both Tanjero and
overlying Kolosh Formation in which no one can observe the contact line
between these two formations in the field especially in Smaquli and Dokan area.
Another important point to be mentioned is the lack of any reworked
foraminiferal evidence to be observed within (P0) Guembelitria cretacea zone
and overlying biozones in mentioned areas. The K/T contact in the studied areas
has been interpreted as conformable contact because of the absence of any
sedimentological break, or erosional surface, no condensed section no
mineralogical record observed in addition to uninterrupted biostratigraphic
record.
As defined above and based on the associated planktonic foraminiferal
assemblage, the Guembelitria cretacea zone coincides with the same zone
recorded from Tunisia (Li & Keller, 1998 b); from Egypt (Keller, 2002); Eastern
Tethys Israel (Keller, 2004); general (Olsson et al., 2000), (Berggren & Norris,
1997), (Berggren et al.,1995), (Keller, 1996); DSDP Site 525A (Abramovich and
Keller, 2003) ; Spain (Pardo et al., 1996), (Smit, 2005). P0 is also equivalent to
the Lower part of Guembelitria cretacea zone from Egypt by (Obaidalla, 2005)
and Tunisia (Arenillas et al., 2000) and Canudo et al., 1991, Caravaca and
Agost from Spain.
The age estimation of this biozone by (Olsson et al., 2000) (Keller, 2002, and
2004), records the earliest Paleocene (Danian), with the time span of (65.00Ma)
to (64.97Ma) estimating absolute ages based on magnetochron ages. (30 Ky)
ages with (24 Ky/m) high rate of deposition in Gali section. (Figs. 3.12 -13)
Age: Earliest Paleocene (Danian).
3.2.2.2- (Pá) Parvularugoglobigerina eugubina Total Range Zone
Definition: Biostratigraphic interval is characterized by the total range of the
nominate taxon. (Liu, 1993, emended. of Pá of Blow, 1979; Luterbacher and
Premoli Silva, 1964). (Plate .24, Figs.9-14)
Luterbacher & Premoli Silva (1964) firstly used the Globigerina eugubina
Zone for the Early Paleocene of Central Italy. Blow, (1979) used
Parvularugoglobigerina longiapertura to characterize the earliest Paleocene
Zone P? (Globorotalia (Turborotalia) longiapertura). However, this assemblage
72