Akademik Veri Yönetim Sistemi
21th International Petroleum and Natural Gas Congress and Exhibition of Turkey, Ankara, Türkiye, 27 - 29 Eylül 2023, cilt.1, sa.1, ss.883-885
‘Pithonellid calcitarchs” (middle? Cenomanian) are
found in the organic-rich limestones of the Derdere
Formation at SE Türkiye in the northern Arabian
Platform. Unfortunately, little is known about the
pithonellid calcitarchs in the Cretaceous strata of
Türkiye. The diversity or occurrence of “pithonellid
calcitarchs’ is extremely low in the study area.
Three morphogroups of “pithonellid calcitarchs’ are
distinguished in the study. In the literature, Pithonella
sphaerica (Kaufmann, 1865) and P. ovalis (Kaufmann,
1865), both dominant in the pithonellid assemblages, and
Bonetocardiella conoidea (Bonet, 1956), less abundant,
are mentioned. The marked increase in pithonellids may
be related to an early transgressive phase due to sealevel
changes during the Cretaceous time, particularly
evident in the Cenomanian (Upper Cretaceous). They
represent a potentially useful correlative biomarker
horizon in the successions of SE Türkiye. ‘Pithonellid
calcitarchs’ have been interpreted as indicators of
increased nutrient input and discussed in terms of
paleoecology/paleoenvironment and their association
with roveacrinid crinoids. In the base of the Derdere
Formation, a carbonate succession deposited under
eutrophic conditions, there is a positive relationship
between “pithonellid calcitarchs” and nutrient input, as
indicated by the low diversity or abundance of benthic
and planktonic foraminifera. Platform drowning or
possibly a mid–Cenomanian event (MCE1) and an
anoxic bottom environment could be related to the
abundance peak of “pithonellid calcitarchs’. In addition,
the terminology of calcisphere is also discussed in
this study. Nowadays, the term calcispheres is used
inconsistently. To eliminate this confusion, the term
“pithonellid calcitarchs” is proposed to be used in both
global and regional studies.