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

Chapter one
Introduction
CHAPTER ONE
Introduction
1.1- Preface
The Tanjero, Kolosh and Red Bed Series basin, as a part of the Neotethys,
was strongly deformed by the Alpine orogeny during their activity continued
from Jurassic to Miocene where a huge thickness of sediments was
accumulated. These successions are generally well exposed in different
localities and different types of stratigraphic units in Zagros mountain regions
such as the Balambo, Qulqula, Qamchuqa, Aqra-Bekhme, Kometan, Shiranish
and Tanjero Formations, in addition to the Kolosh, Gercus Formations and
Red Bed Series. The basins of these units have a complicated history of
development and tectonics, this history was demonstrated by different
characteristics of these stratigraphic units.
Biostratigraphic analysis involves the interpretation of the nature of
contact between Tanjero / Kolosh and Tanjero / Red Bed series, evolution,
estimation the age of biozones by high resolution planktonic foraminiferal
zonation and paleoenvironmental interpretation in accordance to planktonic
and benthonic foraminiferal assemblages relationship by examining different
geologic variables associated in this study. The geologic variables in the
present study include the traditional and biostratigraphic analysis based on
detail study of (5) exposed sections throughout the studied area. The detailed
field and lab studies were directed towards planktonic foraminiferal zonation
and paleoenvironmental interpretation to interpret architecture and
biostratigraphic relation, in addition to the correlation and comparisons with
similar and related studies achieved in this field regionally or globally.
During the last decades the analysis of the Cretaceous/ Tertiary (K/T)
boundary has been one of the most frequently mentioned topics in the earth
science and several hypotheses have been suggested to explain the causes
behind the global mass extinction in several groups of organism across this
boundary, both marine and terrestrial forms were affected by the extinction
event, which implies a multitude of causes for the Late Cretaceous extinctions,
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