The genetic relationship between mafic dike swarms and plutonic reservoirs in the mesozoic of central chile (30°–33°45′S): insights from AMS and geochemistry     

Christian Creixell  Miguel Ángel Parada  Diego Morata  Pierrick Roperch  César Arriagada 《International Journal of Earth Sciences》2009,98(1):177-201

Five mafic dike swarms between 30° and 33°45′S were studied for their geochemical signature and kinematics of magma flow directions by means of AMS data. In the Coastal Range of central Chile (33°−33°45′S), Middle Jurassic dike swarms (Concón and Cartagena dike swarms, CMDS and CrMDS, respectively) and an Early Cretaceous dike swarm (El Tabo Dike Swarm, ETDS) display the presence of dikes of geochemically enriched (high-Ti) and depleted (low-Ti) basaltic composition. These dikes show geochemical patterns that are different from the composition of mafic enclaves of the Middle Jurassic Papudo-Quintero Complex, and this suggests that the dikes were injected from reservoirs not related to the plutonic complex. The mantle source appears to be a depleted mantle for Jurassic dikes and a heterogeneous-enriched lithospheric mantle for Cretaceous dikes. In the ETDS, vertical and gently plunging magma flow vectors were estimated for enriched and depleted dikes, respectively, which suggest, together with variations in dike thickness, that reservoirs were located at different depths for each dike family. In the Elqui Dike Swarm (EDS) and Limarí Mafic Dike Swarm (LMDS), geochemical patterns are similar to those of the mafic enclaves of the Middle Jurassic plutons. In the LMDS, east to west magma flow vectors are coherent with injection from neighbouring pluton located to the east. In the EDS, some dikes show geochemical and magma flow patterns supporting the same hypothesis. Accordingly, dikes do not necessarily come from deep reservoir; they may propagate in the upper crust from coeval shallow pluton chamber. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

Velocity dispersion estimates of APM galaxy clusters     

M. Victoria Alonso  Carlos Valotto  Diego G. Lambas  Hernán Muriel 《Monthly notices of the Royal Astronomical Society》1999,308(3):618-622

We present 83 new galaxy radial velocities in the field of 18 APM clusters with redshifts between 0.06 and 0.13. The clusters have Abell identifications and the galaxies were selected within 0.75  h ⁻¹ Mpc in projection from their centres. We derive new cluster velocity dispersions for 13 clusters using our data and published radial velocities.
We analyse correlations between cluster velocity dispersions and cluster richness counts as defined in Abell and APM catalogues. The correlations show a statistically significant trend although with a large scatter, suggesting that richness is a poor estimator of cluster mass irrespectively of cluster selection criteria and richness definition. We find systematically lower velocity dispersions in the sample of Abell clusters that do not fulfil APM cluster selection criteria, suggesting artificially higher Abell richness counts owing to contamination by projection effects in this subsample.  相似文献   

Three-dimensional nonlinear random wave groups in intermediate water depth     

Felice Arena  Alfredo Ascanelli  Vincenzo Nava  Diego Pavone  Alessandra Romolo 《Coastal Engineering》2008,55(12):1052-1061

High waves at ocean occur during a complex space–time evolution of wave groups. In this paper the nonlinear structure of three-dimensional sea wave groups at intermediate water depth is investigated. To this purpose, the Boccotti's Quasi-Determinism theory is firstly applied to describe the linear wave groups when a given exceptionally high crest occurs. Then, the second-order correction to the linear solution is derived for the general condition of three-dimensional wave groups, at a finite water depth. Several numerical applications, finally, have been carried out in order to show how both the spectral bandwidth and the directional spreading modify the nonlinear high waves at different water depth.  相似文献   

Embedded beam element with interaction surface for lateral loading of piles          下载免费PDF全文

Diego F. Turello  Federico Pinto  Pablo J. Snchez 《国际地质力学数值与分析法杂志》2016,40(4):568-582

This paper presents a numerical formulation of a three dimensional embedded beam element for the modeling of piles, which incorporates an explicit interaction surface between soil and pile. The formulation is herein implemented for lateral loading of piles but is able to represent soil–pile interaction phenomena in a general manner for different types of loading conditions or ground movements. The model assumes perfect adherence between beam and soil along the interaction surface. The paper presents a comparison of the results obtained by means of the present formulation and by means of a previously formulated embedded pile element without interaction surface, as well as reference semi‐analytical solutions and a fully 3D finite element (FE) model. It is seen that the proposed embedded element provides a better convergence behavior than a previously formulated embedded element and is able to reproduce key features of a full 3D FE model. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Fake quakes in Italy through parametric catalogues and seismological compilations: case histories and typologies     

Daniela Bellettati  Romano Camassi  Diego Molin 《地学学报》1993,5(5):488-495

The Italian catalogue contains many earthquakes of moderate to high epicentral intensity which are located in areas of low seismicity and near big cities. Some of them have been inserted in the catalogue after one historical record only. This study investigates many such events in the 1000–1690 time-window showing that a great number of them are fake. Starting by an operational definition of ‘fake quake’, this paper shows the procedures adopted, and the main results which contribute in a significant way to the reassessment of seismicity and seismic hazard.  相似文献   

Satellite galaxies and fossil groups in the Millennium Simulation     

Laura V. Sales  Julio F. Navarro †  Diego G. Lambas  Simon D. M. White  Darren J. Croton 《Monthly notices of the Royal Astronomical Society》2007,382(4):1901-1916

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The case for non-Gaussianity on cluster scales     

H. Mathis  J. M. Diego  J. Silk 《Monthly notices of the Royal Astronomical Society》2004,353(2):681-688

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Lightning climatology in Colombia     

Diaz  Fernando  Ortiz  Diego  Roman  Francisco 《Theoretical and Applied Climatology》2022,149(1-2):69-82

Theoretical and Applied Climatology - Colombia’s lightning climatology was studied using 16 years of high-resolution data from the Tropical Rainfall Measuring Mission Lightning Imaging Sensor...  相似文献   

Effects of the intertidal burrowing crab<Emphasis Type="Italic">Chasmagnathus granulatus</Emphasis> on infaunal zonation patterns,tidal behavior,and risk of mortality     

Mauricio?EscapaEmail author  Oscar?Iribarne  Diego?Navarro 《Estuaries and Coasts》2004,27(1):120-131

Rhythmic movements in response to tidal cycles are characteristic of infaunal inhabitant of intertidal soft-bottoms, allowing them to remain in the area with best living conditions. The effect of bioturbators as modifier of local environmental conditions and thus of gradients in intertidal habitats, has not been investigated yet. The Atlantic estuarine intertidal areas are dominated by the burrowing crabChasmagnathus granulatus that generates strong environmental heterogeneity by affecting the physical-chemical characteristics of the sediment. The comparison between intertidal areas with and without crab shows that sediments in the crab beds remain more humid, softer, and homogeneous across the intertidal and along the tidal cycle than areas without crabs. The densities of infauna were higher at high intertidal zones in crab beds than in similar areas without crabs. Infaunal organisms performed vertical movements into the sediment following the tidal cycle that were always of higher magnitude in habitats without crabs. Infaunal species tend to spend most of the time buried into the sediment in the crab bed. Migratory shorebirds use the Atlantic estuarine environments as stopover or wintering sites. They feed (mainly on polychaetes) in the low intertidal zones of both habitats (with and without crabs), but they also feed in the upper intertidal of the crab bed; polychaete per capita mortality rate is higher in the upper part of the crab bed. Environmental heterogeneity produced by crab disturbance has an effect on the infaunal behavior, risk of mortality, and the zonation pattern. This is another example of the ecosystem engineering ability of a burrowing intertidal species.  相似文献   

Taphonomic and archeological aspects of massive mortality processes in guanaco (Lama guanicoe) caused by winter stress in Southern Patagonia     

Juan Bautista Belardi  Diego Rindel   《Quaternary International》2008,180(1):38

The taphonomic and archeological implications of massive mortality patterns of guanaco (Lama guanicoe) populations due to winter stress are discussed, considering both local and regional scales. The presentation has its focus in the Lake Cardiel basin, Southern Patagonia, Argentina. Winter stress is not an unusual event in Patagonian ecosystems and it produces a seasonal and predictable output: a huge number of dead guanacos in certain loci.Five faunal assemblages formed in 2000 are discussed, three in rock shelters and two at open-air settings, considering guanaco individuals/bone preservation, age and sex structure, death positions, degree of interment, carnivore damages, trampling marks, and the association between guanaco individuals/bones and archeological material (mainly lithic artifacts). Conditions exist for the commingling of naturally formed guanaco bone assemblages and archeological materials. The taphonomic signature of this mortality pattern is analysed, and criteria developed that allow identification of the potential mixture between archeological material and modern guanaco bones. From an archeological point of view, the potential scavenging opportunities brought by these guanaco mortality events to hunter-gatherer populations are explored.In sum, the results of this study are twofold. First, it brings new data on the regional taphonomy of guanacos and its implications for the archeological record. Second, it invites consideration of these mass mortality events in the context of strategies employed by hunter-gatherer populations to cope with their environment.  相似文献