Alpine metamorphism of low-grade schists from the Slavonian Mountains (Croatia): new P-T and geochronological constraints     

Dražen Balen  Hans-Joachim Massonne  Iva Lihter 《International Geology Review》2018,60(3):288-304

Low-grade schists from the Slavonian Mountains (Tisia Mega-Unit, Mt Papuk, Croatia), previously assigned to Precambrian to Lower Palaeozoic metamorphism, have been subjected to geochemical investigations, P-T modelling, and in situ age dating of monazite. The studied fine-grained metasediments consist of chlorite (5–15 vol.%), K white-mica (40–55 vol.%), quartz (20–35 vol.%), feldspar (albite 15–20 vol.%), opaques (<2 vol.%), and accessory minerals. According to their whole-rock geochemistry, the detritus of the former sediments came from upper crustal felsic rocks as they occur, for instance, at Mt Papuk. The schists show a complex microtectonic fabric, including well-developed schistosity systems. P-T pseudosections in the system MnNCKFMASHTO, constructed for typical schists of the study area, resulted in peak P-T conditions of 445–465 °C and 4.6–6.0 kbar for a sample from Kutjevo (eastern part of the study area) and 450–460 °C and 5.2–6.0 for a Vranovo sample (western part). Electron microprobe (EMP) dating of monazite in the schists gave a weighted average age of 109.0 ± 13.1 Ma (2σ) eventually with three subgroups of ages at 225 ± 63 (two analyses), 114 ± 24 and 83 ± 22 Ma. We conclude that the metamorphism of the studied schists at depths of c. 20 km is due to an Alpine collisional event.  相似文献   

High-P (P = 1.5–1.8 GPa) blueschist from Elba: Implications for underthrusting and exhumation of continental units in the Northern Apennines     

Samuele Papeschi  Giovanni Musumeci  Hans-Joachim Massonne  Francesco Mazzarini  Eric James Ryan  Giulio Viola 《Journal of Metamorphic Geology》2020,38(5):495-525

The Acquadolce Subunit on the Island of Elba, Italy, records blueschist facies metamorphism related to the Oligocene–early Miocene stages of continental collision in the Northern Apennines. The blueschist facies metamorphism is represented by glaucophane- and lawsonite-bearing metabasite associated with marble and calcschist. These rock types occur as lenses in a schistose complex representing foredeep deposits of early Oligocene age. Detailed petrological analyses on metabasic and metapelitic protoliths, involving mineral and bulk-rock chemistry coupled with P–T and P–T–X(Fe₂O₃) pseudosection modelling using PERPLE_X, show that the Acquadolce Subunit recorded nearly isothermal exhumation from peak pressure–temperature conditions of 1.5–1.8 GPa and 320–370°C. During exhumation, peak lawsonite- and possibly carpholite- or stilpnomelane-bearing assemblages were overprinted and partially obliterated by epidote-blueschist and, subsequently, albite-greenschist facies metamorphic assemblages. This study sheds new light on the tectonic evolution of Adria-derived metamorphic units in the Northern Apennines, by showing (a) the deep underthrusting of continental crust during continental collision and (b) rapid exhumation along ‘cold’ and nearly isothermal paths, compatible with syn-orogenic extrusion.  相似文献   

From Kyoto via Moscow to nowhere?     

Zbigniew W. Kundzewicz  Hans-Joachim Schellnhuber  Anastasia Svirejeva-Hopkins 《Climate Policy》2013,13(1):81-90

Abstract

Since the World Climate Change Conference held in the autumn of 2003 in Moscow, Russian Federation, the fate of international climate policy architecture designed around the Kyoto Protocol hangs in the balance. After the withdrawal of the USA from the Kyoto Protocol, the condition of its ratification cannot be met without the Russian Federation. There has been a considerable uncertainty as to Russia's intentions regarding ratification of Kyoto. In this contribution, an attempt is made to identify the Russian motives and concerns, and explain their attitudes regarding the Kyoto Protocol. Pressures against and for ratification are discussed. Finally, a few comments are made about the future of the efforts to solve the global environmental problem of protecting the Earth's climate.  相似文献   

Technical risks and best available technology (BAT) of hydraulic fracturing in unconventional natural gas resources     

Hans-Joachim Uth 《Environmental Earth Sciences》2014,72(6):2163-2171

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Über einige Beziehungen zwischen Befischungsintensität,Befischungskoeffizient und Ertrag     

Hans-Joachim Elster 《Aquatic Sciences - Research Across Boundaries》1949,11(3-4):352-360

Zusammenfassung Erh?ht man die Intensit?t der Befischung in einem Gew?sser, so steigt der durchschnittliche Fangertrag nicht im selben Verh?ltnis, sondern um so langsamer, je h?her die Befischungsintensit?t schon vorher war. Diese Beziehungen werden mathematisch formuliert. Es werden Tabellen aufgestellt, die den neuen Befischungskoeffizienten in Abh?ngigkeit vom alten und die ?nderung des Ertrages pro Fischer bzw. pro Befischungseinheit nach dem Wechsel der Befischungsintensit?t zu berechnen gestatten. Schlie?lich werden die einschr?nkenden Bedingungen besprochen, unter denen diese theoretischen Beziehungen in der Praxis angewendet werden k?nnen.

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Summary By increasing the intensity of fishing in a lake the average catch will not increase in the same ratio, but the slower the higher the intensity of fishing has been before. These relations are brought to a mathematical formula. Tabels are made which allow to compute the new coefficient of fishing depending on the old and the change of the catch per fisherman, resp. per unity of fishery after the changing of the intensity of fishing. After all one is treating the restrictive conditions by which these theoretical relations may be employed in practice. Die Arbeit wurde Herrn Oberregierungsrat Dr. F.Lücke, Direktor des Instituts für Fischverarbeitung in Hamburg-Altona, zum 60. Geburtstag gewidmet.

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Sustainable management of mixed demersal fisheries in the North Sea through fleet-based management a proposal from a biological perspective     

Ratz  Hans-Joachim; Bethke  Eckhard; Dorner  Hendrik; Beare  Doug; Groger  Joachim 《ICES Journal of Marine Science》2007,64(4):652-660

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Chemical composition of crustal xenoliths from southwestern Syria: Characterization of the upper part of the lower crust beneath the Arabian plate     

Abdulrahman Al-Safarjalani  Sobhi Nasir  Thomas Fockenberg  Hans-Joachim Massonne 《Chemie der Erde / Geochemistry》2009,69(4):359-375

The chemical bulk rock composition of 37 xenoliths, brought from depths of 25–30 km to the surface by penetrating Cenozoic alkali basaltic magma, from the Shamah Harrat, southwestern Syria, was determined by XRF spectroscopy. The geochemical character of these xenoliths points to original marls and within-plate igneous rocks. To obtain the mean chemical composition of the corresponding upper portion of the lower crust, the compositions of the 37 xenoliths were averaged and a leucogranitic and upper crustal component was added to account for assimilation by the Cenozoic magmas. This mean is more basic (SiO₂—50.5 wt%) and richer in HFSE, LREE, and LILE compared to compositions of the lower crust given by Taylor and McLennan [1985. The Continental Crust: Its Composition and Evolution. Blackwell, Oxford, 312pp.] and Rudnick and Gao [2005. Composition of the continental crust. In: Rudnick, R.L. (Ed.), The Crust. Treatise on Geochemistry, vol. 3. Elsevier, Amsterdam, pp. 1–64]. Calculations of the seismic compressional-wave velocity from our compositional mean, using the PERPLE_X computer software, yielded values around 6.85 km/s, which are in accordance with reported seismic studies for the corresponding depth levels (6.7–7.1 km/s).  相似文献   

Chemistry of chromium spinel in high-Mg rocks from the Morungava Intrusion,Cretaceous Paraná Igneous Province,southernmost Brazil     

Pinto  Viter Magalhães  Massonne  Hans-Joachim  Wildner  Wilson  Hartmann  Léo Afraneo  Debruyne  David  Theye  Thomas 《Mineralogy and Petrology》2019,113(6):765-782

Mineralogy and Petrology - Mafic-ultramafic intrusions within continental flood basalt terrains are frequently associated with Cu-Ni-PGE mineralization. This study aims to constrain the...  相似文献   

Search for strange attractors in magnetic field data: An example from a tertiary volcanic area near Bonn, Germany     

Sabrina Leonardi  Hans-Joachim Kümpel 《Journal of Geodynamics》1996,21(4):329-338

Spatial variations of the magnetic field, measured at the Earth's surface, are mainly due to geological inhomogeneities within the crust. The present state of the crust, in turn, reflects its past dynamical processes and evolution. We analyzed the magnetic field intensity along a few but densely sampled profiles in a Tertiary volcanic province near Bonn, Germany. The aim was to find out whether the variation of the magnetic intensity can be related to a deterministic, although chaotic, generating system or to a stochastic one. In the former case, the geodynamical history would depend on a few degrees of freedom, whereas in the latter case, the parameters to take into account were so many that a statistic approach appears to be more suitable. Since strange attractors do not emerge from the analyzed data, we exclude the presence of a chaos generating system. Autocorrelation functions and a rescaled-range analysis, on the other hand, reveal and quantify a certain degree of correlation among successive data points and allow calculation of a range of spectral exponents in log-log diagrams, which are clearly distinct from those of white noise and Brownian motion. Only one of the profiles exhibits similarity to uncorrelated or white noise. In this case, the signal variations do not result from the local geology but from a buried gas pipe-line, aligned subparallel to that profile. If self-organized crustal evolution generally produces signatures that can be described as correlated noise, within a limited bandwidth of spectral exponents, erraneous or disturbed data could eventually be discriminated from records containing purely natural data by applying analysis tools of the dynamic system theory together with autocorrelation tests.  相似文献   

Antagonistic structures in border areas: Local milieux and local politics in the Polish-German twin city Gubin/Guben     

Ulf Matthiesen  Hans-Joachim Bürkner 《GeoJournal》2001,54(1):43-50

Cross-border communication and co-operation at the Eastern fringe of the European Union seems so far to have been a matter of political initiative and a lot of good will at the levels of national, regional and local governance. This article maintains that everyday culture must be given more notice when cross-border activities are regarded at the local level, especially in twin cities. The case of the German-Polish twin city Guben/Gubin reveals a strong tendency towards a new divergence of thought and action between formal and informal levels of action, namely the level of local politics and governance and the level of local everyday milieux. While the politics of Euroregions, local administrations and local governments is very often directed towards establishing symbolic gestures of border-crossing and mutual understanding, social milieux at the ‘base’ of local societies are rather driven by a paradoxical mixture of hope, anxiety, resentments and prejudice, thus producing contradictions and even conflict with official political initiative. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献