Lumineszenz-Datierung der Löss-Paläoboden-Sequenz in der Kiesgrube Gaul/Weilbach, Südhessen

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, chronostratigraphyLumineszenz-Datierung der Löss-Paläoboden-Sequenz in der Kiesgrube Gaul/Weilbach, Südhessen Kurzfassung: Eine mächtige Löss-Paläoboden-Sequenz des Mittel- und Spätpleistozäns ist in der Kiesgrube Gaul östlich von Weilbach im südlichen Taunusvorland aufgeschlossen. Lösse der letzten drei Glazialzyklen, mit zwischengeschalteten Paläoböden, sind aufgeschlossen. Sieben Proben wurden mit der Lumineszenz-Datierungsmethode, basierend auf einem post-IR IRSL Messprotokoll, untersucht, um einen verlässlicheren chronologischen Rahmen für diese Sedimente zu etablieren. Die „fading“ korrigierten IR50 und die pIRIR225 Alter sind für fast alle Proben in guter Übereinstimmung. Die IRSL Alter reichen von 23.7 ± 1.6 ka bis >350 ka und deuten an, dass der älteste Löss während des marinen Isotopenstadiums (MIS) 10 oder früher abgelagert wurde, und dass die Weilbacher Humuszonen sehr wahrscheinlich während einer späten Phase des MIS 7 gebildet wurden. Lösse über dem fCc Horizont wurden sehr wahrscheinlich während des MIS 6 abgelagert, was darauf hindeutet, dass die Reste des Paläobodens nicht mit dem letzten Interglazial korrelieren. Die beiden obersten Proben deuten darauf hin, dass der jüngste Löss während dem letzten Pleniglazial (Oberwürm, MIS 2) abgelagert wurde. Mit dem pIRIR225 Signal konnten Alter bis ~350 ka für die Proben der Löss-Paläoboden-Sequenz in der Kiesgrube Gaul gemessen werden

Luminescence Dating of Fluvial Deposits from the Weser Valley, Germany

Luminescence dating was applied on coarse-grained monomineralic potassium-rich feld-spar and polymineralic fine-grained minerals of five samples derived from fluvial deposits of the Riv-er Weser in northwestern Germany. We used a pulsed infrared stimulated luminescence (IRSL) single aliquot regenerative (SAR) dose protocol with an IR stimulation at 50°C for 400 s (50 μs on-time and 200 μs off-time). In order to obtain a stable luminescence signal, only off-time IRSL signal was rec-orded. Performance tests gave solid results. Anomalous fading was intended to be reduced by using the pulsed IRSL signal measured at 50°C (IR50), but fading correction was in most cases necessary due to moderate fading rates. Fading uncorrected and corrected pulsed IR50 ages revealed two major fluvial aggradation phases during the Late Pleistocene, namely during marine isotope stage (MIS) 5d (100 ± 5 ka) and from late MIS 5b to MIS 4 (77 ± 6 ka to 68 ± 5 ka). The obtained luminescence ages are consistent with previous 230Th/U dating results from underlying interglacial deposits of the same pit, which are correlated with MIS 7c to early MIS 6

Odour and H2S degradation in a full scale biofilter with a mineral based organic coated filter media

[Abstract] In order to minimize the odorous emissions from sludge storage tanks on the waste water treatment plant «Niederrad» of the city of Frankfurt/Main, about 12.000 m3/h of foul air has to be treated. Due to high Hydrogen-Sulphide (H2S) loads, the installed standard biofilter systems failed operation after one year. Thus, one of the existing filter beds was filled with a mineral based organic coated material; the other one was re-filled at the same time with a standard biofilter media to allow a comparative study. In a long term monitoring program from May 2006 to June 2007, both media were compared regarding degradation of H2S and odour. The one-year measurement program revealed that the mineral high performance media performs much better then the standard organic media

Luminescence dating of the loess/palaeosol sequence at the gravel quarry Gaul/Weilbach, Southern Hesse (Germany)

Eine mächtige Löss-Paläoboden-Sequenz des Mittel- und Spätpleistozäns ist in der Kiesgrube Gaul östlich von Weilbach im südlichen Taunusvorland aufgeschlossen. Lösse der letzten drei Glazialzyklen, mit zwischengeschalteten Paläoböden, sind aufgeschlossen. Sieben Proben wurden mit der Lumineszenz-Datierungsmethode, basierend auf einem post-IR IRSL Messprotokoll, untersucht, um einen verlässlicheren chronologischen Rahmen für diese Sedimente zu etablieren. Die „fading“ korrigierten IR50 und die pIRIR225 Alter sind für fast alle Proben in guter Übereinstimmung. Die IRSL Alter reichen von 23.7 ± 1.6 ka bis >350 ka und deuten an, dass der älteste Löss während des marinen Isotopenstadiums (MIS) 10 oder früher abgelagert wurde, und dass die Weilbacher Humuszonen sehr wahrscheinlich während einer späten Phase des MIS 7 gebildet wurden. Lösse über dem fCc Horizont wurden sehr wahrscheinlich während des MIS 6 abgelagert, was darauf hindeutet, dass die Reste des Paläobodens nicht mit dem letzten Interglazial korrelieren. Die beiden obersten Proben deuten darauf hin, dass der jüngste Löss während dem letzten Pleniglazial (Oberwürm, MIS 2) abgelagert wurde. Mit dem pIRIR225 Signal konnten Alter bis ~350 ka für die Proben der Löss-Paläoboden-Sequenz in der Kiesgrube Gaul gemessen werden

Combining 10Be surface exposure and OSL dating to reconstruct Holocene lake-level fluctuations: a case study at Tangra Yumco (southern Tibet)

Abstract HKT-ISTP 2013 B

Сложность алгоритмов криптографической системы Эль–Гамаля и ихэффективность

Objective. - Electrical remodeling as well as atrial contractile dysfunction after the conversion of atrial fibrillation (AF) to sinus rhythm (SR) are mainly caused by a reduction of the inward L-type Ca2+ current (ICaL). We investigated whether the expression of L-type Ca2+-channel subunits was reduced in atrial myocardium of AF patients. Methods. - Right atrial appendages were obtained from patients undergoing coronary artery bypass graft surgery (CAD, n = 35) or mitral valve surgery (MVD, n = 37). Seventeen of the CAD patients and 18 of the MVD patients were in chronic (>3 months) AF, whereas the others were in SR. The protein expression of the L-type Ca2+-channel subunits {alpha}1C and {beta}2 was quantified by western blot analysis. Furthermore, we measured the density of dihydropyridine (DHP)-binding sites of the L-type Ca2+ channel using 3H-PN220-100 as radioligand. Results. - Surprisingly, the {alpha}1C and the {beta}2-subunit expression was not altered in atrial myocardium of AF patients. Also, the DHP-binding site density was unchanged. Conclusion. - The protein expression of the L-type Ca2+-channel subunits {alpha}1C or {beta}2 is not reduced in atrial myocardium of AF patients. Therefore, the reduced ICaL might be due to downregulation of other accessory subunits ({alpha}2{delta}), expression of aberrant subunits, changes in channel trafficking or alterations in channel function

Aeolianite and barrier dune construction spanning the last two glacial-interglacial cycles from the southern Cape coast, South Africa

The southern Cape region of South Africa has extensive coastal aeolianites and barrier dunes. Whilst previously reported, limited knowledge of their age has precluded an understanding of their relationship with the climatic and sea-level fluctuations that have taken place during the Late Quaternary. Sedimentological and geomorphological studies combined with an optical dating programme reveal aeolianite development and barrier dune construction spanning at least the last two glacial–interglacial cycles. Aeolianite deposition has occurred on the southern Cape coast at ca 67–80, 88–90, 104–128, 160–189 and >200 ka before the present. Using this and other published data coupled with a better understanding of Late Quaternary sea-level fluctuations and palaeocoastline configurations, it is concluded that these depositional phases appear to be controlled by interglacial and subsequent interstadial sea-level high stands. These marine transgressions and regressions allowed onshore carbonate-rich sediment movement and subsequent aeolian reworking to occur at similar points in the landscape on a number of occasions. The lack of carbonates in more recent dunes (Oxygen Isotope Stages 1/2 and 4/5) is attributed not to leaching but to changes to carbonate production in the sediment source area caused by increased terrigenous material and/or changes in the balance between the warm Agulhas and nutrient-rich Benguela ocean current