A deglaciation model of the Oberhasli,Switzerland          下载免费PDF全文

Christian Wirsig  Jerzy Zasadni  Susan Ivy‐Ochs  Marcus Christl  Florian Kober  Christian Schlüchter 《第四纪科学杂志》2016,31(1):46-59

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Ugandan geosites          下载免费PDF全文

A. Schumann  A. Muwanga  T. Lehto  M. Staudt  T. Schlüter  V. Kato  A. Namboyera 《Geology Today》2015,31(2):59-67

Geosites are important and/or unique geological or geographical features of significance. Typically they comprise geological, palaeontological, as well as archaeological sites. Geosites should be regarded as deserving to be preserved and protected, either from the elements or from destructive human activities, both for the community and future generations. A good knowledge of geological heritage, and a healthy respect for it, is an important factor in the holistic approach for sustainable development. Very often, these sites bear a multi‐faceted ‘story’, which may date back from very recent times to billions of years ago. As such, geosites are of great educational and scientific value. In Africa, such sites have not been receiving the attention they deserve. Only a few countries on the continent acknowledge their importance. Within the framework of a Sustainable Management of Mineral Resources Project (SMMRP), geological mapping, geochemical surveys and mineral resources assessment in selected areas of Uganda have been completed under the umbrella of the Geological Survey of Finland (GTK), and the Department of Geological Survey and Mines (DGSM, Uganda). Apart from recording ‘hard‐tough’ geology, 62 geosites were documented in 2010 and 2011. For the first time, such sites have been incorporated in the new geological maps of the country (at a scale of 1: 250 000). It is possible that this is the first time that such places have been shown on geological maps of Africa. Currently, the extreme north‐east of the country is being geologically mapped by DGSM, with the eventuality of more possible geosites being discovered.  相似文献   

Cosmogenic isotope burial dating of fluvial sediments from the Lower Rhine Embayment,Germany     

Andreas Dehnert  Oliver Kracht  Frank Preusser  Naki Akçar  Hans Axel Kemna  Peter W. Kubik  Christian Schlüchter 《Quaternary Geochronology》2011,6(3-4):313-325

Cosmogenic isotope burial dating, using ¹⁰Be and ²⁶Al, was applied to Plio–Pleistocene fluvial successions from the Lower Rhine Embayment, Germany. The approach consists of three principal steps: (1) measurement of cosmogenic nuclides in depth profiles, (2) modelling of hypothetical nuclide concentrations based on a first-order conceptualisation of the geological context and the principal succession of depositions and subsequent erosional and burial phases, and (3) using parameter estimation to identify values for the a priori unknown model parameters (burial age, initial nuclide concentrations, terrace erosion rates) that result in minimal disagreement between hypothetical and measured nuclide concentrations.The Late Pliocene Kieseloolite Formation was dated to 3650 ± 1490 ka and the Early Pleistocene Waalre Formation to 900 ± 280 ka. The unconformably overlying Upper Terrace Formation revealed ages of 740 ± 210 ka and 750 ± 250 ka for the two different sites. These findings are in good agreement with independent age control derived by bio-, magneto-, and litho-stratigraphy. Furthermore, identifiability and uncertainty analysis reveal a relationship between burial depth and sensitivity of isotope concentrations to burial age and erosion rate. Our results indicate that using shallower buried samples would enable a considerably more robust estimation of the burial age and the terrace erosion rate. Uncertainties arose mainly from nuclide measurements, and not from the uncertainties derived from modelling or insufficient knowledge of nuclide production and decay properties.  相似文献   

Response to citation by Gerhard Wörner     

Hans-Ulrich Schmincke 《International Journal of Earth Sciences》2014,103(1):5-6

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Land subsidence pattern controlled by old alpine basement faults in the Kashmar Valley, northeast Iran: results from InSAR and levelling     

Jan Anderssohn  Hans-Ulrich Wetzel  Thomas R. Walter  Mahdi Motagh  Yahya Djamour  Hermann Kaufmann 《Geophysical Journal International》2008,174(1):287-294

Fluid storage systems, such as oil, gas, magma or water reservoirs, are often controlled by the host rock structure and faulted terrain. In sedimentary basins, where no direct information about underlying structure is available, the pattern of ground deformation may allow us to assess the buried fault arrangement. We provide an example in the semi-arid area of Iran, in the Kashmar Valley, a region subject to land subsidence due to water overexploitation. Geodetically determined subsidence rates in the Kashmar Valley exceed 15–30 cm yr⁻¹. The pattern of surface deformation is strongly non-uniform and displays NE–SW elongated bowls of subsidence. The trend resembles old Cretaceous-to-Tertiary faults that evolved during early alpine tectonic deformation. Although these early alpine structures are considered tectonically inactive in the present day, the observed land subsidence pattern indicates significant structural control on the geometry of the aquifer basin and its deformation during reservoir drainage.  相似文献   

Middle Jurassic stromatactis mud-mounds in the Pieniny Klippen Belt (Carpathians) — A possible clue to the origin of stromatactis     

R. Aubrecht  J. Schlögl  M. Krobicki  H. Wierzbowski  B.A. Matyja  A. Wierzbowski 《Sedimentary Geology》2009,213(3-4):97-112

Four occurrences of Jurassic stromatactis mud-mounds were found in the Czorsztyn Unit of the Pieniny Klippen Belt (Western Carpathians) — in western Slovakia (Slavnické Podhorie, Babiná), and in the Transcarpathian Ukraine (Priborzhavskoe and Veliky Kamenets). Their stratigraphic range is from Bajocian to Callovian. The mounds consist of micropeloidal mudstones, wackestones to packstones with a fauna including pelecypods, brachiopods, ammonites and crinoids. Spicules and skeletons of siliceous sponges are abundant in every section. All of the mounds contain networks of stromatactis cavities that are partially filled with radiaxial fibrous calcite (RFC) and locally by internal sediments. At Slavnické Podhorie, the sparry masses that fill stromatactis cavities are weathered out and show casts of sponges. Parallel study of the weathered casts and their cross-sections in slabs showed that they bear all the signs of stromatactis (relatively flat bottoms and digitate upper parts, RFC initial fillings and eventual blocky calcite later filling). Almost no original sponge structures were preserved. This strongly supports the possible sponge-related origin for stromatactis cavities.  相似文献   

Lateglacial and early Holocene dynamics of adjacent valley glaciers in the Western Swiss Alps     

Inga Schindelwig  Naki Akçar  Peter W. Kubik  Christian Schlüchter 《第四纪科学杂志》2012,27(1):114-124

The Alps play a pivotal role for glacier and climate reconstructions within Europe. Detailed glacial chronologies provide important insights into mechanisms of glaciation and climate change. We present 26 ¹⁰Be exposure dates of glacially transported boulders situated on moraines and ice‐moulded bedrock samples at the Belalp cirque and the Great Aletsch valley, Switzerland. Weighted mean ages of ～10.9, 11.1, 11.0 and 9.6 ka for the Belalp, on up to six individual moraine ridges, constrain these moraines to the Egesen, Kartell and Schams stadials during Lateglacial to early Holocene times. The weighted mean age of ～12.5 ka for the right‐lateral moraine of the Great Aletsch correlates with the Egesen stadial related to the Younger Dryas cooling. These data indicate that during the early Holocene between ～11.7 and ～9.2 ka, glaciers in the Swiss Alps seem to have been significantly affected by cold climatic conditions initiated during the Younger Dryas and the Preboreal Oscillation. These conditions resulted in glacier margin oscillations relating to climatic fluctuations during the second phase of the Younger Dryas – and continuing into Boreal times – as supported by correlation of the innermost moraine of the Belalp Cirque to the Schams (early) Holocene stage. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

A statistical analysis of climate variability and ecosystem response in the German Bight     

Merja H. Schlüter  Agostino Merico  Karen H. Wiltshire  Wulf Greve  Hans von Storch 《Ocean Dynamics》2008,58(3-4):169-186

We compiled homogeneous long-term time series comprising 39 variables representing the German Bight and for the period 1975–2004. A diverse set of variables was selected to cover multiple trophic levels and different environmental forcing thus to examine long-term changes in this coastal region. Previous studies have hypothesised the presence of regime shifts in observations extending over the entire North Sea. Focusing on a smaller spatial scale, and closer to the coast, we investigated the major modes of variability in the compiled time series using principal component analysis. The results obtained confirm a previously identified regime shift in the North Sea in 1987/1988 and suggest that the German Bight is dominantly characterised by long-term modes of variability. In the German Bight, the shift of 1987/1988 is driven primarily by temperature, Gulf Stream index, frost days and Secchi depth. Changes in some of the ecosystem variables (plankton and fish) appear to be related to changes in these driving variables. In particular, we documented strong positive correlations between the long-term trend showed by the first principal component and herring, Noctiluca scintillans, and, to a lesser extent, Pleurobrachia pileus. Two gadoids, namely cod and saithe, showed negative correlations with the observed long-term mode of variability. Changes in the sum of five small calanoid copepods were, however, less marked. Phosphate and ammonium exhibited a decreasing trend over the last 30 years. Diatoms and Calanus helgolandicus did not show evidence of changes in concert to this trend. Specific analyses of the data divided into three different subsets (biological, climatic and chemical) characterise the climate of the German Bight as highly dynamic also on short timescales (a few years) as compared to much smoother biological and chemical components. The dynamic regime of the German Bight taken together with a low correlation between the major mode of variability and phytoplankton and zooplankton data suggests that the lower trophic levels of this ecosystem are remarkably resilient.  相似文献   

Behavior of Steroid Hormones and Conjugates During Wastewater Treatment – A Comparison of Three Sewage Treatment Plants     

Michael P. Schlüsener  Kai Bester 《洁净——土壤、空气、水》2008,36(1):25-33

The fate of the steroid hormones 17 β‐estradiol, estrone, estriol, 16 α‐hydroxyestrone, and β‐estradiol 17‐acetate, the hormone‐conjugates β‐estradiol 3‐sulfate and estrone 3‐sulfate, and the oral contraceptives 17 α‐ethinylestradiol and mestranol were studied during wastewater treatment as wastewater treatment plants are the major source contamination of urban surface waters with steroid hormones. The elimination efficiencies of three different concepts of WWTPs, i. e., activated sludge versus trickling filter, were compared over four weeks at different weather conditions. While larger WWTPs operating on activated sludge eliminated hormones more constantly than smaller WWTPs, heavy rainfall events led to a collapse of the elimination efficiency. By using trickling filter techniques for the treatment of wastewater an elimination of the steroid hormones could not be observed. Additionally, mass flows on a per person basis are compared. In the three experiments, which ran continuously for four weeks each, it turned out that the concentrations of ethinylestradiol and mestranol were below 6 ng/L in all samples. The inflow concentrations were 70 to 82 ng/L (estrone), 17 to 44 ng/L (estradiol), 61 to 130 ng/L (hydroxyestrone), 189 to 255 ng/L (estriol), 10 to 17 ng/L (estrone‐3‐sulfate) and about 28 ng/L (estradiol‐3‐ sulfate). While in the activated sludge treatment plants the elimination of estrone was 90 and 50%, respectively, estrone was formed from precursors in the trickling filter plant. A similar situation occurred for 17β‐estradiol, estrone 3‐sulfate, and estradiol 3‐sulfate. Hydroxyestrone was eliminated with similar efficiencies in all wastewater treatment plants (64 to 82%), as well as estriol (34 to 69%). Accordingly, the emissions of the wastewater treatment plants differed largely and were not attributed to the size of the respective plant, only.  相似文献   

Benthic organic carbon flux and oxygen penetration reflect different plankton provinces in the Southern Ocean     

Oliver Sachs  Eberhard J. Sauter  Michael Schlüter  Michiel M. Rutgers van der Loeff  Kerstin Jerosch  Ola Holby 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(8):1319-1335

For the investigation of organic carbon fluxes reaching the seafloor, oxygen microprofiles were measured at 145 sites in different sub-regions of the Southern Ocean. At 11 sites, an in situ oxygen microprofiler was deployed for the measurement of oxygen profiles and the calculation of organic carbon fluxes. At four sites, both in situ and ex situ data were determined for high latitudes. Based on this data set as well as on previous published data, a relationship was established for the estimation of fluxes derived by ex situ measured O₂ profiles. The fluxes of labile organic matter range from 0.5 to 37.1 mg C m^?2 d^?1. The high values determined by in situ measurements were observed in the Polar Front region (water depth of more than 4290 m) and are comparable to organic matter fluxes observed for high-productivity, upwelling areas like off West Africa. The oxygen penetration depth, which reflects the long-term organic matter flux to the sediment, was correlated with assemblages of key diatom species. In the Scotia Sea (～3000 m water depth), oxygen penetration depths of less than 15 cm were observed, indicating high benthic organic carbon fluxes. In contrast, the oxic zone extends down to several decimeters in abyssal sediments of the Weddell Sea and the southeastern South Atlantic. The regional pattern of organic carbon fluxes derived from microsensor data suggests that episodic and seasonal sedimentation pulses are important for the carbon supply to the seafloor of the deep Southern Ocean.  相似文献