Fossil microorganisms from the Eocene Messel oil shale of Southern Hesse, Germany
- In this study the rich variety of fossil microorganisms and other ultrastruchlres in the Messel oil shale is documented. The taphonomy of the micro- and the macro organisms is discussed and a basic model for microbial life in the Eocene Lake Messel is proposed. Documentation of the Messel microbiota was made using a scanning electron microscope fitted with an energy-dispersive X-ray analyzer, and a transmission electron microscope. The most common objects discovered were fossil bacteria in the form of cocci, coccobacilli, bacilli, curved rods and filaments, preserved as moulds, crusts, casts, encrusted casts and clay-coated casts. The main lithifying mineral is apatite, followed by siderite. The bacteria occur on fossil remains of macroorganisms. Sideritic bacteria are usually found on keratinous substrates, whereas apatitic bacteria occur preferentially on fish remains. Lithification of the bacteria was selective. It is suggested that the preserved bacteria were heterotrophic, Gram-positive anaerobes, which may have belonged to the group of clostridians.
Luminescence dating of the loess/palaeosol sequence at the gravel quarry Gaul/Weilbach, Southern Hesse (Germany)
Esther Dorothe Schmidt
- A thick Middle and Late Pleistocene loess/palaeosol sequence is exposed at the gravel quarry Gaul located east of Weilbach in the southern foreland of the Taunus Mountains. The loess/palaeosol sequence correlates to the last three glacial cycles. Seven samples were dated by luminescence methods using an elevated temperature IRSL (post-IR IRSL) protocol for polymineral fine-grains to determine the deposition age of the sediment and to set up a more reliable chronological framework for these deposits. The fading corrected IR50 and the pIRIR225 age estimates show a good agreement for almost all samples. The fading corrected IRSL ages range from 23.7 ± 1.6 ka to >350 ka indicating that the oldest loess was deposited during marine isotope stage (MIS) 10 or earlier and that the humic-rich horizon (Weilbacher Humuszone) was developed during the late phase of MIS 7. Loess taken above the fCc horizon most likely accumulated during MIS 6 indicating that the remains of the palaeosol are not belonging to the last interglacial soil. The two uppermost samples indicate that the youngest loess accumulated during MIS 2 (Upper Würmian). Age estimates for the loess-palaeosol sequence of the gravel quarry Gaul/Weilbach could be obtained up to ~350 ka using the pIRIR225 from feldspar. Keywords: loess, luminescence dating, IRSL, fading, Weilbach, chronostratigraphy
Kaiserin Maria Alexandrowa von Rußland, geb. Prinzessin Marie von Hessen-Darmstadt (1824-1880) : Umrisse ihrer Biographie
Continuity or new beginning? : Isaac Emil Lichtigfeld, Rabbi in Frankfurt am Main and Hesse, 1954-1967