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The Serra Leste region, located in the northeast portion of Carajás Mineral Province (PA), hosts important chrome-PGE, Au–Pd–Pt, Cu–Mo–Au, iron, and manganese deposits and occurrences related to different geological settings. We present a regional prospective model with focus on PGE mineralizations based on airborne geophysics (magnetometry, gamma-ray spectrometry and time domain electromagnetometry) and geological data. Geological and geophysics data analysis indicate a plausible correspondence between areas with meta-mafic–ultramafic rocks and low values in gamma spectrometry, mainly for the thorium channel. The meta-ultramafic units of the complexes, the main host rock of the PGE mineralization, are well defined by analytic signal from the anomalous magnetic field and by the apparent conductance anomalies derived from the GEOTEM system. The combination of the derivative products with updated geological data of the Serra Leste region and PGE-Luanga deposit enable to establish a regional prospective model for PGE and the identification of new targets within the studied area.  相似文献   
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Summary. The Gubbio section, in the Umbrian Apennines, yielded a sequence of Upper Cretaceous polarity zones precisely corresponding to the sea-floor magnetic anomalies of that age; the Gubbio polarity zones have been dated with planktonic foraminifera. As a test of the validity of the Gubbio reversal sequence, we have studied the section at Moria, 16 km to the north. The polarity sequence at Moria closely agrees with the sequence at Gubbio; only the two thinnest polarity subzones were not found. Comparison of polarity zone thicknesses in the two sections gives an excellent correlation. Declinations in the upper part of the Moria section are somewhat erratic, suggesting the possibility of detachment surfaces and relative structural rotations at these levels. Remanent magnetic intensity varies in a cyclical pattern that is unmistakably the same in the Gubbio and Moria sections. The results from the Moria section provide strong confirmation of the validity of the magnetic polarity sequence established at Gubbio.  相似文献   
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A type III solar burst was observed at seven frequencies between 3.5 MHz and 80 kHz by the Michigan experiment aboard the IMP-6 satellite. From the data we can determine burst direction-of-arrival as well as time-of-arrival. We predict these quantities using simple models whose parameters we vary to obtain a good fit to the observations. We find that between 3.5 MHz and 230 kHz the observed radiation was emitted at the fundamental of the local plasma frequency while below 230 kHz it was emitted at the second harmonic. The exciter particles that produced the burst onset and burst peak have velocities of 0.27 and 0.12, respectively, in units of the velocity of light.  相似文献   
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Development of a system of indicators for sustainable port management   总被引:2,自引:0,他引:2  
The 1998 project ECOPORT, “Towards A Sustainable Transport Network”, developed by the Valencia Port Authority (VPA), established the bases for implementing an Environmental Management System (EMS) in industrial harbours. The use of data and information shall always be required to develop an efficient EMS. The objective of the present research (INDAPORT) study is to propose a system of sustainable environmental management indicators to be used by any port authorities. All activities performed within a port area are analysed for any potential environmental impacts and risks.

An environmental analysis of port activities has been carried out with the objective of designing the indicators system. Twenty-one corresponding activities have been identified for large industrial ports. Subsequently, the same methodology developed to date will be later applied to other Spanish and European ports. The study has been developed by using an original system and a methodology, which simultaneously use stage diagrams and systemic models (material and energy flow charts). Multi-criteria analysis techniques were used to evaluate potential impacts (identification of factors and evaluation of impacts).  相似文献   

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A single confidently dated species of cephalopod is so far known in the Tremadocian of the southern Central Andean Basin (NW Argentina and southern Bolivia). This species belongs to the Eothinoceratidae and has a strong affinity mainly with Avalonia. During the Floian, a notable increase in diversity took place, with the appearance of a variety of families represented by several genera, in particular, within the Family Eothinoceratidae. In addition to the previously described species from southern Bolivia, we evaluate the other records of that family from the Central Andean Basin, and propose the following new taxa: Saloceras sikus sp. nov., Saloceras quena sp. nov., Mutveiceras gen. nov., and Mutveiceras cienagaensis sp. nov. We also describe Margaritoceras diploide, Margaritoceras sp., and Mutveiceras sp. From a palaeogeographic perspective, the cephalopod fauna shows affinities mainly with those of England, Wales, and the Montagne Noire (cold water Gondwana and peri‐Gondwana). As with other cephalopod faunas of mid to high palaeolatitudes, eothinoceratids occur along with other cephalopods forming assemblages of low morphological diversity. We interpret the forms described here as demersal with a subvertical poise, but capable of making rapid buoyancy changes, living in a wide spectrum of shallow offshore to shoreface settings. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
119.
One of the main sources of uncertainty in estimating climate projections affected by global warming is the choice of the global climate model (GCM). The aim of this study is to evaluate the skill of GCMs from CMIP3 and CMIP5 databases in the north-east Atlantic Ocean region. It is well known that the seasonal and interannual variability of surface inland variables (e.g. precipitation and snow) and ocean variables (e.g. wave height and storm surge) are linked to the atmospheric circulation patterns. Thus, an automatic synoptic classification, based on weather types, has been used to assess whether GCMs are able to reproduce spatial patterns and climate variability. Three important factors have been analyzed: the skill of GCMs to reproduce the synoptic situations, the skill of GCMs to reproduce the historical inter-annual variability and the consistency of GCMs experiments during twenty-first century projections. The results of this analysis indicate that the most skilled GCMs in the study region are UKMO-HadGEM2, ECHAM5/MPI-OM and MIROC3.2(hires) for CMIP3 scenarios and ACCESS1.0, EC-EARTH, HadGEM2-CC, HadGEM2-ES and CMCC-CM for CMIP5 scenarios. These models are therefore recommended for the estimation of future regional multi-model projections of surface variables driven by the atmospheric circulation in the north-east Atlantic Ocean region.  相似文献   
120.
We present field and seismic evidence for the existence of Coniacian–Campanian syntectonic angular unconformities within basal foreland basin sequences of the Austral or Magallanes Basin, with implications for the understanding of deformation and sedimentation in the southern Patagonian Andes. The studied sequences belong to the mainly turbiditic Upper Cretaceous Cerro Toro Formation that includes a world‐class example of conglomerate‐filled deep‐water channel bodies deposited in an axial foredeep depocentre. We present multiple evidence of syntectonic deposition showing that the present internal domain of the fold‐thrust belt was an active Coniacian–Campanian wedge‐top depozone where deposition of turbidites and conglomerate channels of Cerro Toro took place. Cretaceous synsedimentary deformation was dominated by positive inversion of Jurassic extensional structures that produced elongated axial submarine trenches separated by structural highs controlling the development and distribution of axial channels. The position of Coniacian‐Campanian unconformities indicates a ca. 50–80 km advance of the orogenic front throughout the internal domain, implying that Late Cretaceous deformation was more significant in terms of widening the orogenic wedge than all subsequent Andean deformation stages. This south Patagonian orogenic event can be related to compressional stresses generated by the combination of both the collision of the western margin of Rocas Verdes Basin during its closure, and Atlantic ridge push forces due to its accelerated opening, during a global‐scale plate reorganization event.  相似文献   
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