Sedimentologic to metamorphic processes recorded in the high-pressure/low-temperature Mesozoic Rosetta Marble of Anatolia     

F. Scheffler  R. Oberhänsli  A. Pourteau  A. Immenhauser  O. Candan 《International Journal of Earth Sciences》2016,105(1):225-246

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The Inorganic Carbon Chemistry in Coastal and Shelf Waters Around Ireland     

Triona McGrath  Evin McGovern  Rachel R. Cave  Caroline Kivimäe 《Estuaries and Coasts》2016,39(1):27-39

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Barium Isotopic Compositions of Geological Reference Materials          下载免费PDF全文

Kirsten van Zuilen  Thomas F. Nägler  Thomas D. Bullen 《Geostandards and Geoanalytical Research》2016,40(4):543-558

The interest in variations of barium (Ba) stable isotope amount ratios in low and high temperature environments has increased over the past several years. Characterisation of Ba isotope ratios of widely available reference materials is now required to validate analytical procedures and to allow comparison of data obtained by different laboratories. We present new Ba isotope amount ratio data for twelve geological reference materials with silicate (AGV‐1, G‐2, BHVO‐1, QLO‐1, BIR‐1, JG‐1a, JB‐1a, JR‐1 and JA‐1), carbonate (IAEA‐CO‐9) and sulfate matrices (IAEA‐SO‐5 and IAEA‐SO‐6) relative to NIST SRM 3104a. In addition, two artificially fractionated in‐house reference materials BaBe12 and BaBe27 (δ^137/134Ba = ?1.161 ± 0.049‰ and ?0.616 ± 0.050‰, respectively) are used as quality control solutions for the negative δ‐range. Accuracy of our data was assessed by interlaboratory comparison between the University of Bern and the United States Geological Survey (USGS). Data were measured by MC‐ICP‐MS (Bern) and TIMS (USGS) using two different double spikes for mass bias correction (¹³⁰Ba–¹³⁵Ba and ¹³²Ba–¹³⁶Ba, respectively). MC‐ICP‐MS measurements were further tested for isobaric and non‐spectral matrix effects by a number of common matrix elements. The results are in excellent agreement and suggest data accuracy.  相似文献   

Non-stationary emission of the blazar S4 0954+658 over a wide range of wavelength     

A. E. Volvach  V. S. Bychkova  M. G. Larionov  N. S. Kardashev  L. N. Volvach  V. V. Vlasyuk  O. I. Spiridonova  A. Lähteenmäki  M. Tornikoski  M. F. Aller  H. D. Aller  G. Pooley  L. Carrasco  A. Porras  E. Recillas 《Astronomy Reports》2016,60(12):1035-1045

Data from long-term multi-frequency monitoring are used to analyze variations in the flux density of the active galactic nucleus S4 0954+658. These data were obtained at the CrimeanAstrophysical Observatory, the Metsähovi Radio Observatory of Aalto University, the University of Michigan Radio Astronomy Observatory, the Cavendish Laboratory of Cambridge University, the Special Astrophysical Observatory, and the National Institute of Astrophysics, Optics, and Electronics; 0.1–300-GeV data from the Fermi space gamma-ray observatory were also used. Radio data at 4.8, 8, 14.5, 15, 22.2, and 36.8 GHz are considered together with optical and near-infrared data in the R, J, H, and K filters.  相似文献   

The Plankogel detachment of the Eastern Alps: petrological evidence for an orogen‐scale extraction fault          下载免费PDF全文

S. Schorn  K. Stüwe 《Journal of Metamorphic Geology》2016,34(2):147-166

The so‐called Plankogel detachment is an east‐west trending, south‐dipping low‐angle structure that juxtaposes the high‐P rocks of the eclogite type locality of the eastern European Alps against amphibolite facies rocks to the south. It occurs in both the Saualpe and Koralpe Complex in eastern Austria. During Cretaceous intracontinental subduction, the footwall and the hangingwall units of the Plankogel detachment were buried to different crustal levels as inferred by pseudosection modelling and conventional thermobarometry: ~23–24 kbar and 640–690 °C for the eclogite facies units in the footwall of the detachment and ~12–14 kbar and 550–580 °C for the amphibolite facies metapelites in the hangingwall. Despite the different peak metamorphic conditions, both sides of the detachment display a common overprint at conditions of ~10 kbar and 580–650 °C. From this, we infer a two‐stage exhumation process and suggest that this two‐stage process is best interpreted tectonically in terms of slab extraction during Eoalpine subduction. The first stage of exhumation occurred due to the downward (southward) extraction of a lithospheric slab that was localized in the trace of the Plankogel detachment. The later stage, however, is attributed to more regional erosion‐ or extension‐driven processes. Since the Plankogel detachment is geometrically related to a crustal‐scale shear zone further north (the Plattengneiss shear zone), we suggest that both structures are part of the same extraction fault system along which the syn‐collisional exhumation of the Eoalpine high‐P units of the Eastern Alps occurred. The suggested model is consistent with both the mylonitic texture of the Plattengneiss shear zone and the overall ambiguous shear sense indicators present in the entire region.  相似文献   

Seismic rupture during the 1960 Great Chile and the 2010 Maule earthquakes limited by a giant Pleistocene submarine slope failure     

Jacob Geersen  David Völker  Jan H. Behrmann  Dirk Kläschen  Wilhelm Weinrebe  Sebastian Krastel  Christian Reichert 《地学学报》2013,25(6):472-477

Determining factors that limit coseismic rupture is important to evaluate the hazard of powerful subduction zone earthquakes such as the 2011 Tohoku‐Oki event (Mw = 9.0). In 1960 (Mw = 9.5) and 2010 (Mw = 8.8), Chile was hit by such powerful earthquakes, the boundary of which was the site of a giant submarine slope failure with chaotic debris subducted to seismogenic zone depth. Here, a continuous décollement is absent, whereas away from the slope failure, a continuous décollement is seismically imaged. We infer that underthrusting of inhomogeneous slide deposits prevents the development of a décollement, and thus the formation of a thin continuous slip zone necessary for earthquake rupture propagation. Thus, coseismic rupture during the 1960 and 2010 earthquakes seems to be limited by underthrusted upper plate mass‐wasting deposits. More generally, our results suggest that upper plate dynamics and resulting surface processes can play a key role for determining rupture size of subduction zone earthquakes.  相似文献   

Bücher- und Zeitschriftenschau     

St. 《International Journal of Earth Sciences》1910,1(6):346-350

Ohne Zusammenfassung  相似文献   

Early Weichselian interstadial (MIS 5c) summer temperatures were higher than today in northern Fennoscandia     

Minna Väliranta  Hilary H. Birks  Karin Helmens  Stefan Engels  Mikko Piirainen 《Quaternary Science Reviews》2009,28(9-10):777-782

Only fragmentary biostratigraphical interstadial data exist from northern European high latitudes. The palaeoenvironmental interpretations for the early part of the Last Glaciation in northern Fennoscandia are mainly based on palynological evidence that suggests open birch woodland and a sub-arctic climate. Plant macrofossils from the Sokli sediment sequence in Finnish Lapland provide different evidence of interstadial climate conditions. The assemblage includes several species that currently have considerably more southern distribution ranges. This indicates that ca 100,000 years ago summer temperatures were warmer than today. The mean minimum July temperature may have been as high as 16 °C and the effective temperature sum may have been 1000 in day-degree units (d.d.), the modern values being 13 °C and 650 d.d., respectively. The contemporary astronomical forcing mechanisms may have resulted in a weaker north–south temperature gradient and a longer growing period, creating more favourable climate conditions compared with today.  相似文献   

The framing of climate change and development: A comparative analysis of the Human Development Report 2007/8 and the World Development Report 2010     

Des Gasper  Ana Victoria Portocarrero  Asuncion Lera St.Clair 《Global Environmental Change》2013,23(1):28-39

The Human Development Report 2007/8 (HDR) and the World Development Report 2010 (WDR) are both devoted to the connections between climate change and development. The reports provide very different perspectives on where the key challenges reside. Their policy proposals are also different, but much less so. Using a combination of frame and content analysis complemented with attention to how these institutions and their knowledge production processes operate, the paper develops a structured comparison of the problem-framing and solution-framing in the Overviews of the two reports. It compares the reports’ conceptions of development; their normative content and the roles given to human rights; the pathways and solutions the agencies defend, and how protective they are of the poor; the status given to proposed market solutions; what types of information and expert perspective are prioritized and why, and which issues are neglected. Following its stress on human rights and ethical principles, the HDR does not unsettle the market driven solutions to climate change that dominate the global policy arena. Different policy instruments and a fuller institutionalization of its human rights concerns is required, in organizations, processes, methodologies and knowledge networks that could move the ideas forward and continually press for their use. This may require a different model of report preparation.  相似文献   

Würmian deglaciation of western Lake Geneva (Switzerland) based on seismic stratigraphy     

Julien Fiore  Stéphanie Girardclos  André Pugin  Georges Gorin  Walter Wildi 《Quaternary Science Reviews》2011,30(3-4):377-393

Western Lake Geneva (le Petit-Lac) was filled during the Quaternary over a major erosion surface truncating the cemented, folded and thrusted Tertiary sediments of the foreland Alpine basin. The carving of the lake occurred during Quaternary glaciations with ice originating from the Rhone valley catchment basin flowing in two branches oriented SW and NE over the Swiss Plateau. Lake Geneva is situated on the South-Western branch of this paleo ice-cap.For the first time, a dense grid of high-resolution seismic profiles (airgun 5-inch³, airgun 1-inch³ and echosounder) has imaged the whole Quaternary sequence, providing a paleoenvironmental interpretation and a detailed reconstruction of the Rhone glacier retreat stages during glacial events that led to the formation of western Lake Geneva.The Quaternary sequence filling up the bedrock valley is exceptionally thick with up to 220 m of deposits and consists of glacial, glacio-lacustrine and lacustrine sediments. Fourteen seismic units have been defined (units U1–U14). Unit U1 represents the remnants of glacial deposits older than the last glacial cycle, preserved in the deepest part of the lake and in secondary bedrock valleys. Unit U2 represents gravel and sands deposited by meltwater circulation at the bottom of the glacial valley. Unit U3 is a thick, stratified unit marking the beginning of the deglaciation, when the Rhone glacier became thinner and buoyant and allowed the formation of a subglacial lake. Younger glacial units (units U4, U5, U7, U9, U11) are acoustically chaotic sediments deposited subglacially under the water table (undermelt tills), while the glacier was thinning. These glacial units are bounded by synform erosion surfaces corresponding to readvances of the glacier.The transition from a glacial to a glacio-lacustrine environment started with the appearance of a marginal esker-fan system (unit U6). Esker formation was followed by a small advance–retreat cycle leading to the deposition of unit U7. Then, the ice front receded and stratified sediments were deposited in a glacio-lacustrine environment (units U8, U10 and U12). This retreat was punctuated by two readvances – Coppet (unit U9) and Nyon (unit U11) – producing large push moraines and proglacial debris flows. Finally, a lacustrine environment with a characteristic lake current pattern and mass movement deposits took place (units U13 and U14).Except for unit U1, the sedimentary sequence records the Würmian deglaciation in a fjord-like environment occupied by a tidewater glacier with a steep, calving ice front. The presence of an esker-fan system reveals the importance of subglacial meltwater flow in continental deglaciation. Push-moraines and erosion surfaces below the glacier indicate at least 5 readvances during the deglaciation thus revealing that oscillations of ice front are the key process in deglaciation of perialpine fjord-lakes. The dating of these continental glacier fluctuations would allow correlation with oceanic and ice records and help to understand the climatic mechanisms between oceans and continents.  相似文献