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

Chapter Two
Lithostratigraphy
Fig (2. 8) (a) showing reworked fossils of large foram. of Loftusia, Omphalocyclus and
Orbitoides in the transitional zone between Tanjero and Red Bed Series. (b) Showing the
conglomerate bed of 3 m. thick, which contain reworked and dwarfed fossils at the base of Red
Bed Series.
2.5 - Lithostratigraphy of Qulka section (Dokan area)
The measured part of studied section covered 163m of upper part of
Tanjero Formation and 54m from the lower part of Kolosh Formation. The
detailed stratigraphic section is shown in Figs (2.9, 2.10, & 2.11) on both side
of conglomerate bed, which formerly supposed to be the contact or key marker
for Cretaceous/Tertiary boundary in the studied area by different authors. The
well exposed rocks of studied section of Tanjero Formation at Qulka section
represented by 63m of olive green to pale grey marl and bluish white
calcareous marl intervened by streak of limestone veins and 3m dark grey to
olive green soft, friable sandstone occasionally with siltstone, clay ball and
pillow structure at the middle part of this interval. Followed by 59m of
interfingering Aqra Limestone unit which consists of well bedded ridge forming
recrystalized pale grey to yellowish limestone and sandstone to silty limestone
occasionally dolomitized intercalated by thin beds of shale, calcareous shale,
marl and sandstone beds through this interval. The Aqra Limestone interval in
this section varies from its equivalent at Qishlagh and Kato sections, by very
low frequency of macrofossils and short lateral distribution. The interfingering
Aqra limestone unit overlained by 41m of Tanjero flysch type emergence again
by alternation of olive green to dark grey calcareous shale, marl, thin bedded
sandy limestone ,friable weathered sandstone, some pebbly sandstone bluish
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