The Paleogene carbonate deposits of Pabdeh and Jahrum formations are widespread from the northwest (Dashte Zari area) to southwest Shahrekord region in High Zagros Mountains Iran record lateral upward transition open marine into shallow water environment. Formation shows a succession pelagic hemipelagic limestone, argillaceous chert. It consists planktonic wackestone, pellet-planktonic mudstone...

Abstract. Foraminifera are one of the few taxa that preserve their entire ontogeny in fossilised remains. Revealing this through micro-computed tomography (CT) fossil planktonic foraminifera has greatly improved our understanding life history and allows accurate quantification total shell volume, growth rates developmental constraints throughout an individual's life. Studies using CT scans curr...

Understanding the coupling of oxygen, carbon, and sulfur cycles in the past is critical for reconstructing the history of biogeochemical cycles, paleoclimatic variations, and oceanic chemistry. The abundance of sulfur isotopes (dS) in sulfate from ancient marine carbonates, or carbonate-associated sulfate (CAS), is commonly used, along with other archives (mainly evaporites and barite), to esti...

Past greenhouse periods with elevated atmospheric CO2 were characterized by globally warmer sea-surface temperatures (SST). However, the extent to which the high latitudes warmed to a greater degree than the tropics (polar amplification) remains poorly constrained, in particular because there are only a few temperature reconstructions from the tropics. Consequently, the relationship between inc...

[1] Stable isotope and elemental measurements were conducted on foraminifera from a sequence of calcareous pelagic ooze at Ocean Drilling Program Site 1209 to document the thermal evolution of the North Pacific water column over Shatsky Rise and to address long-standing questions about the nature of oceanic circulation in the early Paleogene. A major change in seasonality and water column struc...

An analytical procedure has been developed for the in situ measurement of calcium isotope composition of carbonates with a spatial resolution of 15–20 μm on a Caméca IMS 1270 ion microprobe. By using two Faraday cup detectors, the Ca and Ca can be measured simultaneously, improving the internal reproducibility. Instrumental mass fractionation (IMF) of calcium isotopes was observed to be indepen...

Radiolarians are marine planktonic protists that belong to the eukaryote supergroup Rhizaria together with Foraminifera and Cercozoa. Radiolaria has traditionally been divided into four main groups based on morphological characters; i.e. Polycystina, Acantharia, Nassellaria and Phaeodaria. But recent 18S rDNA phylogenies have shown that Phaeodaria belongs within Cerocozoa, and that the previous...

In the previous paper, geological ages of Late Cretaceous, Paleocene, late Middle to Eocene, Oligocene and early Early Miocene were confirmed at first time, based on occurrences both age diagnostic larger foraminifera associated planktonic foraminifera, from Sashida Limestone included basalt pebbles, Sashida, Kamo-Gun, south Izu Peninsula. Therefore, was made up clastic carbonate rocks various ...

this study is focused on the biostratigraphy, sedimentary environments, facies distribution, and sequence stratigraphy of the coniacian–santonian sediments of tange-bulfaris section. five assemblage zones have been recognized by distribution of the foraminifera in the study area. assemblage zone 1(chara ostracods zone) is coniacian in age and occurs in the lower part of the succession. assembla...