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Estimated adjusted depth of CO2 of FB2001 drill core from Messel

This table contains atmospheric CO2-estimates based on stomata retrieved in the Messel fossil pit and published by Grein (2010) and Grein et al. (2011). The data is based on leaves retrieved from the Messel fossil pit (earliest Middle Eocene; 47.66 to 47.22 Ma). The leaves were microscopically analysed for their stomata density and which was then converted into atmospheric CO2 content (cf. Grein 2010, Grein et al., 2011 for details about the algorithm). The plant fossils were listed with their original outcrop depth which was marked down relative to marker beds. We projected the outcrop depth (m) onto the FB2001 drill core depth using the marker beds as reference horizons. The age (Ma) as well as mean, maximum and minimum of the CO2 estimates are reported as well as the respective plant species.

Recurrence times of siderite layers of FB2001 drill core from Messel

To investigate variability and drivers of extreme precipitation events under high greenhouse gas concentrations prevalent during the Eocene we computed recurrence times of Fe/Ti peaks in the XRF scanning record of FB2001, reflecting siderite layers that are interpreted to reflect strong precipitation events. Fe/Ti-peaks were detected based on a peak-detection algorithm, followed by counting over a sliding window. Recurrence times were calculated based on the number of Fe/Ti peaks per 5 ka window. Upper and lower boundaries of recurrence times are calculated based on bootstrapping. The record covers the period 47.66 to 47.22 Ma

Mean Annual Air Temperatures of FB2001 drill core from Messel

This table contains Mean Annual Temperatures (MAT) reconstructed using branched GDGTs obtained on core FB2001 from Messel (earliest Middle Eocene; 47.66 to 47.22 Ma), relative to the core depth and age. The error given reflects the calibration error. Samples from the depth interval 17.38 to 30.88 m were analyzed in Frankfurt by high-performance liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS) on a Shimadzu UFLC device coupled to an AB Sciex 3200QTrap. Samples from the interval between 35.94 to 70.94 m core analyzed at RWTH Aachen University, Aachen (Germany), using an Agilent 1260 Infinity II HPLC coupled to an Agilent LC/MSD XT mass spectrometer.

XRF Fe/TI and K/Ti ratios of FB2001 drill core from Messel

The data contains Fe/Ti and K/Ti ratios obtained via XRF core scanning of drill core FB2001 from the Messel fossil pit (earliest Middle Eocene; 47.66 to 47.22 Ma) versus core depth and age. Scanning was performed at the Institute of Institute of Earth Sciences, Heidelberg University (Germany), with an Avvatech (Gen. IV) X-Ray Fluorescence Scanner. The purpose of this analysis was to objectively detect and quantify the occurrence of siderite layers in the Messel oil shale. These siderite layers are interpreted to represent extreme precipitation events.

Reconstruction of continental temperatures and oxygen isotope compositions of precipitation based on clumped and oxygen isotope analysis of pedogenic siderites

Earth's climate sensitivity – defined as the temperature increase for a doubling of pCO2 – and the mechanisms responsible for amplification of high latitude warming remain controversial. The latest Paleocene/earliest Eocene (LPEE; 57-55 million years ago) is a time when pCO2 peaked between 1400 and 4000 ppm, which allows us to evaluate the climatic response to high pCO2. Here, we present a reconstruction of continental temperatures and oxygen isotope compositions of precipitation – reflective of specific humidity – based on clumped and oxygen isotope analysis of pedogenic siderites. We show that continental mean annual temperature reached 41 °C in the equatorial tropics, and summer temperatures reached 23 °C in the Arctic. The oxygen isotope compositions of precipitation reveal that compared to the present-day the hot LPEE climate was characterized by an increase in specific humidity and the average residence time of atmospheric moisture and by a decrease in the subtropical-to-polar specific humidity gradient. The global increase in specific humidity reflects the fact that atmospheric vapor content is more sensitive to changes in pCO2 than evaporation and precipitation, resulting in an increase in the residence time of moisture in the atmosphere. Pedogenic siderite data from other super-greenhouse periods support the evidence that the spatial patterns of specific humidity and warmth are related providing new means to evaluate Earth's climate sensitivity.

Teilprojekt C^Teilprojekt A^Teilprojekt F^ImmoRad: Grundlegende Untersuchungen zur Immobilisierung langlebiger Radionuklide durch die Wechselwirkung mit endlagerrelevanten Sekundärphasen^Teilprojekt B^Teilprojekt E, Teilprojekt D

Im vorliegenden Verbundprojekt wird ein auf atomarer Skala basierendes Prozessverständnis der Wechselwirkung von Actiniden und Spaltprodukten mit endlagerrelevanten Mineralen bzw. Mineraloberflächen erlangt, um so Retentionsmechanismen auf langen Zeitskalen zu verstehen und damit einen Beitrag zur sicheren Endlagerung hochradioaktiven Abfalls zu leisten. An der Actiniden-XAS-Beamline ROBL werden XAFS-spektroskopische Untersuchungen bei niedrigsten Konzentrationen und unter Sauerstoffausschluss durchgeführt. Das IRC wird die Kinetic (2-4 Jahre) der Oberflächenreaktionen (Sorption, Reduktion, Kopräzipitation) von Pu(V) und Pu(III) mit Magnetit und einem Fe-Carbonat (Siderit oder Chukanovit) untersuchen. Das IRC wird die reduktive Reaktion von Np(V) mit Mackinawite (FeS) und Magnetit untersuchen; außerdem die mögliche Inkorporation von Np(IV) in Siderit oder Chukanovit. Das IRC wird die von PSI-LEG hergestellten 'solid solutions' zwischen Se(IV/VI) und LDH und Tc(VII) und LDH, sowie die von KIT-IMG hergestellten 'solid solutions' zwischen Se und Eisensulfiden untersuchen. In allen Fällen wird die Struktur und Oxidationsstufe der mit der Festphase assoziierten Actiniden- bzw. Spaltprodukt-Spezies spektroskopisch mit XAFS und teilweise auch mit XPS untersucht. Die Oberflächenspezies werden mit zu synthetisierenden Kopräzipitaten verglichen. Zudem werden die Lösungsbedingungen (Eh, pH, gelöste Ionen) erfasst, um Stabilitätskonstanten der Sorptionskomplexe und Festphasen zu bestimmen

LPEE reconstructions of oxygen and hydrogen isotope compositions of precipitation based on the analysis of pedogenic siderites and published records of plant wax n-alkanes

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