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

Chapter Three Biostratigraphy
Orbigny), Bulimina ovulum Reuss, Oolina apiculata Reuss, Globorotalites
michelinianus (d , Orbigny), Ammodiscus cretaceous (Reuss), A. pruvianus,
Marsonella oxycona (Reuss), Dorothia smokynensis Wall, D. retusa, D.
rosetta, Textularia astutia. Lalicker, Spiroplectamina israelskyi Hillebrandt, S.
laevis. (Roemer), Gyroidina girardana (Reuss), Gyroidinoides globosus.
(Hagenow), Gaudryna pyramidata. Cushman, Clavulinoides globulifera.Ten Dam
&Sigal, Conicospirilina sp. Rotalia sp. Valvulammina sp. Omphalocyclus
macroporus (Lamark), Orbitoides medius (d Archiac), O. tissoti Shlumberger, O.
apiculatus Shlumberger, Lepidorbitioides socialis (Leymerie), Siderolites sp.
Loftusia elongata Brady, L. morgani Douville, L. persica Brady, L. minor Cox , L.
coxi Henson, L. sp.These assemblages of benthonic foraminifera in addition to
macrofossils like echinoides, gastropods, cephalopods, brachiopods, corals and
pelecypods (coral like rudistids ),indicate the fundamental variation in lithology
and Faunal assemblages from Tanjero clastics to the interfingering interval of
Aqra Limestone represents quite graditional change to reefal facies, probably
formed due to the presence of submerged high within the Tanjero foreland
basin at the end of the Maastrichtian resulted from the termination of
Paraxysmal phases of Laramide orogeny. ( Lawa et al.,1998, Al Omari et al.,
1989, Al Mutwali and Abawi, 2005)
The age estimation of this biozone by (Li and Keller, 1998a), records the
time span between (68.33 Ma) to (66.83 Ma) (1500 KY) estimating absolute
ages based on magnetochron ages with (62 ky/m) low rate of deposition in Gali
section, (13, 5 ky/m) high rate sedimentation in Sirwan area. (18 ky/m) high rate
of deposition in Qulka section Dokan area. (Figs. 3.10 -3.11).
Age: Early Late Maastrichtian.
3.2.1.6- Pseudoguembelina hariaensis Interval Zone (CF3)
The Pseudoguembelina hariaensis zone was defined by Li and Killer, (1998a)
as a partial range of the nominate species between the FAD of
Pseudoguembelina hariaensis Nederbragt and the LAD of Gansserina gansseri
(Bolli). In the studied area this zone also marked by the FAD of the nominate
species to the last occurrence of Gansserina gansseri (Bolli). (Plate 16; Fig. 6).It
is covers the intervals of (21)meter in Gali section, (23) meters in Qulka section
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