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

Chapter one
Introduction
1.4.2.2- Red Bed Series (Suwais Group)
The Series was first described by Bolton (1958) as a Suwais Red Beds (the
name comes from Suwais village) in the Imbricate Zone about 20km to the
north of Sangasar town and to the north of the Ranyia city. The lithology of the
series at the type section is divided into four units; they are as follows from
bottom to top:
-Unit 1, Consists of different types of limestone beds (fossiliferous, detrital
and conglomeratic limestone)
-Unit 2, this unit consists of fine clastic (ferruginous red shale and blue
siltstone) with some interlayer of limestone and conglomerate. The
thickness of this unit is about 300m.
-Unit 3, Polymictic conglomerate is containing boulder and blocks of
limestones, chert, igneous and metamorphic rock fragments.
-Unit 4, Composed of marly shale and sandstone with some conglomerate.
Al-Mehaidi (1975), divided the Series at Chwarta area into four parts.
Karim (1975) studied the Series paleontologically and claimed that the age of
the series is Miocene. Buday (1980), reviewed the earlier studies about the
series with illustration of the regional distribution and interpretation of different
lithology. Al-Ameri et al., (1990), investigated the palynology of Unit one of
Suwais Red Beds in Chwarta Area; they concluded that this unit deposited
during Santonian. Lawa et al. (1998), recorded gradational contact between
Red Bed Series and Tanjero Formation in Chwarta area; while Karim
(2004), recorded both gradational and unconformable contact in different
localities in Chwarta and Qandil area.
Al-Qayim (2000) studied the sedimentation and tectonic environment of
the Suwais Red Beds from northeast margin of the Arabian plate, and
concluded that the unit indicates flysch type sequence with variable facies.
Lawa 2004, in Al-Barzinjy, 2005 showed by sketch that the Red Bed
Series have been deposited during Paleocene and in an intermountain basin
above the sea level where the Kolosh Formation located to the southwest of
the series, and separated both basins from each other by mountain ranges.
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