TITLE:
Sequence and Biostratigraphy of Lower Cenozoic Succession in the Kopet-Dagh Basin, NE of Iran
AUTHORS:
Batool Rivandi, Mohammad Vahidinia, Mehdi Nadjafi, Assadolah Mahboubi, Abbas Sadeghi
KEYWORDS:
Kopeh-Dagh Basin; Paleogene; Larger Benthic Foraminifer; Sequence Stratigraphy
JOURNAL NAME:
Open Journal of Geology,
Vol.3 No.3,
July
11,
2013
ABSTRACT: The main purpose of this paper is the sequence
stratigraphy and biostratigraphy of lower Tertiary sediments on the base of larger
benthic foraminifera in northeast of Iran (Chehel-Kaman Formation). This
formation mainly consists of Limestone, dolomite and interbeds of sand, shale and
evaporate sediments. Petrographical studies indicate that these sediments may have
been deposited on a shallow carbonate platform ramp and consist of 4 carbonate lithofacies
(15 subfacies). These lithofacies may have been deposited in open marine, shoal,
lagoon and tidal flat environmental conditions. Sequence stratigraphy analysis led
to identification of 4 third-order depositional sequences, bounded by type 2 (within
the top of the underlying Pestehleigh Formation) and type 1 sequence boundaries
(paleosol). Interpreted sea level curve in this basin can be relatively correlated
with global curves during Paleocene time and a with a sea-level fall occurred in
the latest Paleocene, followed by a rise in the earliest Eocene. Biostratigraphy
study led to the identification of 32 larger benthic Foraminifera genera. The Paleocene/Eocene
boundary has been probably recorded as a thin red paleosol horizon (~10 - 15 cm).