Stable oxygen isotope ratios of foraminiferal calcite are widely used in paleoceanography to provide a chronology of temperature changes during ocean history. It was recently demonstrated that the stable oxygen isotope ratios in planktonic foraminifera are affected by changes of the seawater chemistry carbonate system: the dO of the foraminiferal calcite decreases with increasing CO3 22 concent...

Oxygen isotope records of planktonic foraminifera indicate that Late Eocene and Oligocene tropical sea surface temperatures were as much as 88C lower than present at a time when high latitude sea surface temperatures were higher than present. Using a numerical model which describes oxygen isotope exchange during burial and recrystallization of deep sea carbonate, the effects of diagenesis on bu...

[1] We present stable oxygen isotope ratio (dO) measurements on deep-dwelling planktonic foraminifera from thewesternmargin of the North Atlantic in order to reconstruct the latitude at which the Gulf Stream separated from the western boundary of the Atlantic Ocean in the past. The modern separation latitude can be reconstructed within one degree from dO measured on the fossil shells of deep-dw...

A rapid and large injection of isotopically light carbon into the ocean-atmosphere reservoirs is signaled by a negative carbon isotope excursion (CIE) at the Paleocene-Eocene boundary ~56 m.y. ago. To better understand the extent of ocean warming and acidification associated with the carbon injection we generated elemental and isotopic records of surface and thermocline planktonic foraminifera ...

High precision measurements of Sr/Ca in planktonic foraminifera for the last 150 ka reveal Sr/Ca variations of up to 12% on glacial/interglacial time scales. Although records showing the largest variations appear to be strongly influenced by selective dissolution, other records show Sr/Ca variations of 3–5% that do not covary with indicators of dissolution intensity and that are reproduced in s...

in order to study biostratigraphy of the surgah formation in zagros sedimentary basin, two subsurface sections of this formation in maleh kuh and sarkan oil fields at pol-e-dokhtar area, lorestan province, have been selected. the thickness of surgah formation at maleh kuh and sarkan, was 82 and 46 meters respectively and is composed of shale with intercalation of limestone and calcareous shale....

[1] The carbon isotope ratio (dC) of plant material is commonly used to reconstruct the relative distribution of C3 and C4 plants in ancient ecosystems. However, such estimates depend on the d C of atmospheric CO2 (dCCO2) at the time, which likely varied throughout Earth history. For this study, we use benthic and planktonic dC and dO records to reconstruct a long‐term record of Cenozoic dCCO2....

In this study biostratigraphy of the Upper Cretaceous deposits (Gurpi Formation) in Sepidan section located in the Interior Fars basin (SW Iran) was studied. The Gurpi Formation in this section consists of 360 m lime shale, argillaceous limestone and shale laid continuously on the Ilam Formation and with a paraconformity under the Pabdeh Formation. Nine genera and 27 species of planktonic foram...

Planktonic foraminifera record oceanic conditions in their shell geochemistry. Many palaeoenvironmental studies have used fossil planktonic foraminifera to constrain past seawater properties by defining species based on their shell morphology. Recent genetic studies, however, have identified ecologically distinct genotypes within traditionally recognized morphospecies, signaling potential reper...

[1] Measurements of the calcium isotopic composition (dCa) of planktonic foraminifera from the western equatorial Pacific and the Indian sector of the Southern Ocean show variations of about 0.6% over the past 24 Myr. The stacked dCa record of Globigerinoides trilobus and Globigerina bulloides indicates a minimum in dCasw (seawater calcium) at 15 to 16 Ma and a subsequent general increase towar...