Tectonic setting of the recent damaging seismic series in the Southeastern Betic Cordillera,Spain     

Emilio Rodríguez-Escudero  José J. Martínez-Díaz  José A. Álvarez-Gómez  Juan M. Insua-Arévalo  Ramón Capote del Villar 《Bulletin of Earthquake Engineering》2014,12(5):1831-1854

In this work we analyze the tectonic setting of the recent damaging seismic series occurred in the Internal Zones of the eastern Betic Cordillera (SE Spain) and surrounding areas, the tectonic region where took place the 11th May 2011 Mw 5.2 Lorca earthquake. We revisit and make a synthesis of the seven largest and damaging seismic series occurred from 1984 to 2011. We analyze their seismotectonic setting, and their geological sources under the light of recent advances in the knowledge on active faults, neotectonics, seismotectonics and stress regime, with special attention focused on the Lorca Earthquake. These seismic series are characterized by two types of focal mechanisms, produced mainly by two sets of active faults, NNW–SSE to NNE–SSW small (no larger than 20–30 km) extensional faults with some strike slip component, and E–W to NE–SW large strike slip faults (more than 50 km long) with some compressional component (oblique slip faults). The normal fault earthquakes related to the smaller faults are dominant in the interior of large crustal tectonic blocks that are bounded by the large E–W to NE–SW strike-slip faults. The strike slip earthquakes are associated to the reactivation of segments or intersegment regions of the large E–W to NE–SW faults bounding those crustal tectonic blocks. Most of the seismic series studied in this work can be interpreted as part of the background seismicity that occurs within the crustal blocks that are strained under a transpressional regime driven by the major strike slip shear corridors bounding the blocks. The seismotectonic analysis and the phenomenology of the studied series indicate that it is usual the occurrence of damaging compound earthquakes of M  \(\sim \)  5.0 associated with triggering processes driven by coseismic stress transfer. These processes mainly occur in the seismic series generated by NNW–SSE to NNE–SSW faults. These mechanical interaction processes may induce a higher frequency of occurrence of this kind of earthquakes than considered in traditional probabilistic seismic hazard assessments and it should be taken into account in future seismic hazard assessments.  相似文献   

Adsorption of Arsenite from Groundwater Using Titanium Dioxide          下载免费PDF全文

Miriam Z. López Paraguay  José Apolinar Cortes  Juan F. Pérez‐Robles  María T. Alarcón‐Herrera 《洁净——土壤、空气、水》2014,42(6):713-721

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Immobilisation of Pb and Zn in Soils Using Stabilised Zero‐valent Iron Nanoparticles: Effects on Soil Properties          下载免费PDF全文

María Mar Gil‐Díaz  Araceli Pérez‐Sanz  María Ángeles Vicente  María Carmen Lobo 《洁净——土壤、空气、水》2014,42(12):1776-1784

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Upper Carboniferous retroarc volcanism with submarine and subaerial facies at the western Gondwana margin of Argentina     

M. Koukharsky  L. Kleiman  M. Etcheverría  S. Quenardelle  F. Bercowski 《Journal of South American Earth Sciences》2009,27(4):299-308

During Late Carboniferous times a continental magmatic arc developed at the western margin of Gondwana in South America, as several marine sedimentary basins were formed at the same time in the retroarc region. North of 33°S, at Cordón Agua del Jagüel, Precordillera of Mendoza, Argentina, a volcanic sequence crops out which was emplaced in a submarine environment with some subaerial exposures, and it is intercalated in marine sediments of Agua del Jagüel Formation, which fills of one of these retroarc basins. This paper presents, for the first time, a facies analyses together with geochemical and isotopic data of this volcanic suite, suggesting its deposition in an ensialic retroarc marine basin. The volcanic succession comprises debris flows with either sedimentary or volcanic fragments, base surge, resedimented massive and laminated dacitic–andesitic hyaloclastite, pillow lava, basic hyaloclastite and dacitic–andesitic lavas and hyaloclastite facies. Its composition is bimodal, either basaltic or dacitic–andesitic. The geochemistry data indicate a subalkaline, low K calk-alkaline and metaluminous affinity. The geochemistry of the basalts points to an origin of the magmas from a depleted mantle source with some crustal contamination. Conversely, the geochemistry of the dacites–andesites shows an important participation of both crustal components and subduction related fluids. A different magmatic source for the basalts than for the dacites–andesites is also supported by Sr and Nd isotopic initial ratios and Nd model ages. The characteristics of this magmatic suite suggest its emplacement in an extensional setting probably associated with the presence of a steepened subduction zone at this latitude during Upper Carboniferous times.  相似文献   

IUPA: a tool for the evaluation of the general usefulness of practices for adaptation to climate change and variability   总被引：1，自引：0，他引：1  

P. Debels  C. Szlafsztein  P. Aldunce  C. Neri  Y. Carvajal  M. Quintero-Angel  A. Celis  A. Bezanilla  D. Martínez 《Natural Hazards》2009,50(2):211-233

A prototype multi-purpose index is proposed for use in the evaluation of practices for adaptation to climate variability and change. The Index of Usefulness of Practices for Adaptation (IUPA) allows the user to assign weights and scores to a set of user-defined evaluation criteria. Individual criterion scores are aggregated into a final index value. Both the final value and the individual parameter scores provide useful information for improved decision making in the context of climate change. An innovative aspect of IUPA is that guidance is given to the user through the inclusion of recommendations on evaluation criteria and criterion-specific weight factors. These have been defined by a panel of experts from the Latin-American and Caribbean Region (LAC). Application of the index is demonstrated for an existing adaptation practice from the Coquimbo Region, Chile. The IUPA tool is recommended for use in the evaluation of adaptation practices in their design, implementation and post-implementation phase. It is practical for a quick first assessment or when limited financial resources are available, making the tool especially useful for practitioners in the developing world. The index is flexible both from the perspective of its construction and use. Additional expert opinions can easily be included in the future versions of the tool.  相似文献   

Implications of geomorphological research for recent and prehistoric avalanches and related hazards at Huascaran,Peru   总被引：2，自引：0，他引：2  

Jan Klimeš  Vít Vilímek  Marek Omelka 《Natural Hazards》2009,50(1):193-209

Detailed research of superficial deposits below the northern peak of Huascaran (Cordillera Blanca) provides new information on the limits of a paleo-avalanche originating from this mountain. Geomorphological mapping of the sediments identified glacial deposits, deposits from historical rock-debris avalanches and huge boulders from a paleo-avalanche. Schmidt Hammer rock-hardness tests were used to distinguish between the several generations of rock-debris avalanches, but largely failed to distinguish between the much older moraine and the paleo-avalanche sediments. Thus, only the field geomorphological mapping proved to be reliable for identifying the limits of the paleo-avalanche. The limits identified as granite boulders deposited over volcanic rocks were found to extend 30 m further up the opposite valley slope than previously had been mapped. This larger extent implies a greater volume and/or greater mobility for the prehistoric event.  相似文献   

From emplacement to unroofing: thermal history of the Jiazishan gabbro, Sulu UHP terrane, China     

W. Siebel  M. Danišík  F. Chen 《Mineralogy and Petrology》2009,96(3-4):163-175

On the eastern extremity of the Jiaodong peninsula, China, shoshonitic magmas have been injected into the supracrustal rocks of the Sulu ultra-high pressure (UHP) terrane during the crustal exhumation phase. These granitoids (collectively termed the Shidao igneous complex or Jiazishan alkaline complex) show geochemical and isotopic signatures of an enriched subcontinental lithospheric mantle and intruded soon after the subducted Yangtze crust had reached peak metamorphic pressure conditions (240–220 Ma). We have applied various geochronometers to an alkali-gabbro sample from the Jiazishan pluton and the results allow reconstruction of the Triassic-to-present thermal history. Initial rapid cooling of the gabbro at crustal depths is indicated by the close agreement between the Sm-Nd mineral isochron age (228?±?36 Ma) and the Rb-Sr biotite age (207?±?1) Ma. This interpretation is confirmed by previously published U-Pb zircon ages (225–209 Ma), and ⁴⁰Ar/³⁹Ar amphibole and K-feldspar ages (～214 Ma) from the Jiazishan syenites. A titanite fission-track age of 166?±?8 Ma (closure temperature range 285–240°C) records widespread Jurassic magmatism in the Jiaodong peninsula, indicating that the gabbro reached upper crustal levels before it was reheated by nearby Jurassic plutons. A subsequent cooling and reheating event is indicated by an apatite fission-track age of 106?±?6 Ma which coincides with the emplacement of the adjacent Weideshan pluton (108?±?2 Ma) and postdates a period of regional lithospheric thinning beneath eastern China. A period of slow cooling (or thermal stability) from late Cretaceous to early Tertiary, documented by an apatite (U-Th)/He age of 39?±?5 Ma, was followed by a final stage of more enhanced cooling since the late Eocene. Results of this work imply that the eastern Sulu terrane has experienced a complex cooling and reheating history. Our data are consistent with a model of initial rapid cooling (sudden exhumation) of the UHP terrane, driven by the release of buoyancy forces, followed by two progressively slower cooling intervals (both after renewed crustal reheating) during the Jurassic and Cretaceous.  相似文献   

太湖沉积物中重金属的地球化学形态及特征分析   总被引：24，自引：2，他引：22  

袁旭音  王爱华  许乃政 《地球化学》2004,33(6):611-618

用连续提取法分析了太湖沉积物5种重金属的地球化学形态,对地球化学形态的组成和地理特征进行了分析研究.重金属地球化学形态配分的共同特点是可交换态最低,残渣态最高.两种形态中Cd的可交换态最高,Cr的残渣态最高,可交换态最低.Cd的碳酸盐态较高,Cr的最低;Pb、Cd的Fe-Mn氧化态较高,Cu的偏低;Cu的有机态最高,Cd的最低;Zn的地球化学形态比例大都处于中间.地域上变化较大的元素是Cd和Cu,变化不明显的元素有Pb和Zn.化学成分中Fe2O3、MnO与重金属地球化学形态的相关性最好,TOC与Cu的形态相关系数最高.综合对比分析表明,太湖沉积物重金属的生物有效性以Cd为最高,其次为Pb.  相似文献   

CGCG 292-057: A Near-Distance Merger Galaxy with Double–Double Radio Lobes and X-shape Structure     

M. Jamrozy  D. Kozieł-Wierzbowska  S. Zoła  A. Kuźmicz  J. Machalski 《Journal of Astrophysics and Astronomy》2011,32(4):467-470

J1159+5820 is an extended radio galaxy with a quite unusual morphology, featuring two pairs of radio lobes. Such sources, called double–double radio galaxies, constitute a very rare class of extragalactic radio sources. Furthermore, the extended radio structure of this source shows an X-shape form. According to a much likely scenario, such a morphology is due to interrupting nuclear activity in its central active galactic nucleus. Interestingly, the host of this source is a near-distance bright galaxy named CGCG 292-057, which is clearly disturbed, with tidal features and shells as plausible signs of a recent merger.  相似文献   

Early Ordovician (Floian) ostracods from the Cordillera Oriental,Northwest Argentina     

María Jos Salas 《Geological Journal》2011,46(6):637-650

The ostracod fauna from the Floian (Lower Ordovician) strata of the Cordillera Oriental, Argentina (Acoite Formation) are documented. One new genus Acoitella and four species are recognized, two of which are new (Nanopsis victoria sp. nov. and Conchoprimitia frequens sp. nov.). The diversity of the Early Ordovician ostracod faunas of the Central Andean Basin is evaluated. Compared with other regions, the ostracod diversity, at generic and specific level, of the Cordillera Oriental was comparatively high during the Tremadocian (nine species recorded) and comparatively low during the Floian (four species recorded). The taxonomic composition of the fauna is similar during the entire Early Ordovician of the Cordillera Oriental, where it displays a high percentage of soanellids. The Floian assemblages are characterized by the dominance of the eridostracan C. frequens sp. nov. with a high percentage of nondimorphic palaeocopids: Nanopsis and two genera of the Soanellidae family (Saltite and Acoitella gen nov.). An ostracod shell bed is described and interpreted to be a parautochthonous assemblage, as a result of transport within the same habitat. The composition of the fauna, with the presence of Saltite and Nanopsis, shows significant affinities with East Gondwana. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献