Magmatism-related localized deformation in the mantle: a case study   总被引：2，自引：0，他引：2  

Gy?rgy?Falus  Martyn?R.?Drury  Hermann?L.?M.?van?Roermund  Csaba?SzabóEmail author 《Contributions to Mineralogy and Petrology》2004,146(4):493-505

A deformed composite peridotite-pyroxenite xenolith in Pliocene alkali basalts from the Pannonian Basin (Szentbékkálla, Bakony—Balaton Highland Volcanic Field) has been studied in detail. A narrow shear zone of intense deformation marked by porphyroclast elongation and recrystallization runs along the peridotite-pyroxenite contact. The xenolith contains a large volume of euhedral olivine neoblasts and tablet grains of olivine away from the shear zone interpreted as products of annealing and recrystallization in the presence of grain boundary fluid. Estimates of the time required for growth of recrystallized olivine grains suggest that the annealing took place in situ in the mantle and not during transport of the xenolith in the basalt magma. The grain boundary fluid present during recrystallization was a vapor rich silicate-melt different from the host basaltic melt that entrained the xenolith. This study demonstrates that high-stress deformation zones and associated fluid-assisted recrystallization, which are common features in kimberlite mantle xenoliths, also occur in some mantle xenoliths from alkali basalts. The suggested high-stress deformation zones in the mantle beneath the Pannonian Basin may be produced by paleoseismic events in the lithosphere associated with faulting related to the ascent of basalt magma.Editorial responsibility: J. Hoefs

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Csaba SzabóEmail: Phone: +36-1-2090555Fax: +36-1-3812108

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Die Grundlagen der Deckenhypothese im südlichen Hunsrück     

Hans Cloos  Hermann Scholtz 《International Journal of Earth Sciences》1930,21(5):289-293

Zusammenfassung Eine neue Kartierung der Mitteldevoninsel von Stromberg im südlichen Hunsrück ließ die Frage offen, ob sie ein Fenster in einer Decke sei oder das Ergebnis ortständiger Zusammenfaltung. Dagegen führte die Aufsuchung und Messung von Faltenachsen zu eindeutigen Ergebnissen. Die Achsen fallen allerseits gegen und unter das Gebiet jüngerer Gesteine und schließen also ein Fenster und einen Deckenbau an dieser Stelle aus. Andere Tatsachen, die eine solche Annahme notwendig machten, sind nicht bekannt. Der Bau des Gebietes läßt eine einfachere Deutung aus den örtlichen Verhältnissen zu.Beobachtungen und Folgerungen vonCloos undScholtz, Text vonCloos.  相似文献   

Neue Hilfsmittel für den geologisch-paläontologischen Unterricht     

Hermann Schmidt 《International Journal of Earth Sciences》1928,19(5):423-424

Ohne Zusammenfassung  相似文献   

Tektonische Untersuchungen an Westerwälder Vulkanen     

Hermann Scholtz 《International Journal of Earth Sciences》1928,19(6):439-447

Ohne Zusammenfassung  相似文献   

Geochemische Untersuchungen zur Genese der Strontianitlagerstätten des Münsterlandes     

Hermann Harder 《Contributions to Mineralogy and Petrology》1964,10(2):198-215

Strontianite in Münsterland occurs along with calcite and very little pyrite in discordant gangues in campan limestone and marl. Most investigators hold descent lateral secretion as the probable explanation for its existence. Determination of the strontium in the limestone and in the shell fragments of fossils proved that no change in the strontium content took place towards the gangue, no matter how far one goes, and that consequently a lateral secretion is to be excluded as a possible cause of this development in the deposit area.—The Sr containing solution was introduced from below. The possibilities of the origination of this solutions are discussed: The strontianite is very pure; it contains only 3–9% CaCO₃ (effecting a diminuation of x-ray diffraction data), a maximum of 0,02% BaCO₃, 0,005% MnCO₃ and 0,007% FeCO₃. Pb, Zn, Cu etc. are in the strontianite as well as in the whole gangue material in amounts, which cannot be detected through testing. This determination excludes the possibility, that barren residual liquors of hydrothermal ore veins are being dealt with. Otherwise, for example, traces of lead, copper etc. and a higher barium content would be expected. Deeper continuations of the hydrothermal ore veins cannot be traced. It is thought possible that brine containing strontium from the upper permian salt of Northern Germany led to the segregation of strontianite in the limestone banks. The succession of precipitation (1. calcite, 2. strontianite) is an argument for the transport of Sr in brine solutions. SrCO₃ in NaCl solution is more soluble than CaCO₃. It is contrary in pure water. The leaching of the strontium in permian salts is obviously a lateral secretion.  相似文献   

Biogeochemical ocean-atmosphere transfers in the Arabian Sea   总被引：2，自引：2，他引：2  

S. Wajih A. Naqvi  Hermann W. Bange  Stuart W. Gibb  Catherine Goyet  Angela D. Hatton  Robert C. Upstill-Goddard 《Progress in Oceanography》2005,65(2-4):116

Transfers of some important biogenic atmospheric constituents, carbon dioxide (CO₂), methane (CH₄), molecular nitrogen (N₂), nitrous oxide (N₂O), nitrate , ammonia (NH₃), methylamines (MAs) and dimethylsulphide (DMS), across the air–sea interface are investigated using published data generated mostly during the Arabian Sea Process Study (1992–1997) of the Joint Global Ocean Flux Study (JGOFS). The most important contribution of the region to biogeochemical fluxes is through the production of N₂ and N₂O facilitated by an acute, mid-water deficiency of dissolved oxygen (O₂); emissions of these gases to the atmosphere from the Arabian Sea are globally significant. For the other constituents, especially CO₂, even though the surface concentrations and atmospheric fluxes exhibit extremely large variations both in space and time, arising from the unique physical forcing and associated biogeochemical environment, the overall significance in terms of their global fluxes is not much because of the relatively small area of the Arabian Sea. Distribution and air–sea exchanges of some of these constituents are likely to be greatly influenced by alterations of the subsurface O₂ field forced by human-induced eutrophication and/or modifications to the regional hydrography.  相似文献   

Late-Pleistocene and mid-Holocene environmental changes in highland valley head areas of Santa Catarina state, Southern Brazil   总被引：1，自引：0，他引：1  

Marcelo A.T. de Oliveira  Hermann Behling  Luiz C.R. Pessenda 《Journal of South American Earth Sciences》2008,26(1):55-67

Low resolution of the continental sedimentary record is a common source of skepticism about the application of geomorphology and sedimentology to Quaternary studies. In spite of this, when supported by independent proxy data, geomorphology and sedimentology may favor palaeo-hydrologic interpretation. This paper associates geomorphologic, stratigraphic, sedimentologic, isotopic, palynologic and geochronologic data. The research was conducted in valley head sites in southern Brazilian highlands, under mild subtropical climate. The results point to environmental changes, the ages of which coincide to Marine Isotopic Stages (MIS) 5b, 3, 2 and 1. Although late-Pleistocene temperatures and precipitation were lower than those of today, the study valley heads seem to have sustained locally wetter environments, which fed shallow soil–water saturated zones. These saturated zones are believed to have expanded during transitions between stadial and interstadial states, contributing to hillslope erosion and sedimentation regardless of the sign of the climatic change. The interior organization of holocenic slope-wash deposits suggests that the mid-Holocene climate was drier than today’s and was under the influence of seasonally contrasting precipitation regimes. The predominance of overland flow-related sedimentary records suggests that an excess of precipitation over evaporation influenced local palaeo-hydrology. This palaeo-hydrologic condition seems to have been recurrent and also explains the alternating periods of pedogenesis and sedimentation.  相似文献   

Socotra Island,Yemen: field survey of the 2004 Indian Ocean tsunami     

Hermann M. Fritz  Emile A. Okal 《Natural Hazards》2008,46(1):107-117

The tsunami of 26th December 2004 severely affected Yemen’s Socotra Island with a death at a distance of 4,600 km from the epicenter of the Magnitude 9.0 earthquake. Yemen allowed a detailed assessment of the far-field impact of a tsunami in the main propagation direction. The UNESCO mission surveyed 12 impacted towns on the north and south shores covering from the east to the west tip of Socotra. The international team members were on the ground in Yemen from 11 to 19 October 2006. The team measured tsunami run-up heights and inundation distances based on the location of watermarks on buildings and eyewitness accounts. Maximum run-up heights were typically on the order of 2–6 m. Each measurement was located by means of global positioning systems (GPS) and photographed. Numerous eyewitness interviews were recorded on video. The tsunami impact on Socotra is compared with other locations along the shores of the Indian Ocean.  相似文献   

Experimental subsolidus phase relations in the system CaCO3–CaMg(CO3)2 up to 6.5 GPa and implications for subducted marbles     

Jörg Hermann  Ulrike Troitzsch  Dean Scott 《Contributions to Mineralogy and Petrology》2016,171(10):84

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Correspondence     

Mrs Kathleen Sherrard  Dr Hermann Jaeger 《Australian Journal of Earth Sciences》2013,60(2):351-352

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