Trans-alkaline magmatism in the Serrinha–Pedro Velho Complex,Borborema Province,NE Brazil and its correlations with the magmatism in eastern Nigeria

The Solânea Complex (572 ± 8 Ma) comprises various intrusions that total 200 km². It cuts Palaeoproterozoic migmatized orthogneisses of the Serrinha–Pedro Velho Complex, which is part of the São José do Campestre Massif, North Tectonic Domain of the Borborema Province, NE Brazil. It is a post-collisional intrusion constituted of coarse-grained biotite–amphibole monzogranites, fine-grained leucogranites and diorites. Major, trace and rare earth elements data, used to constrain the origin and nature of these rocks, indicate that the monzogranites display chemical features of weakly peraluminous ferro-potassic trans-alkaline granitoids, similar to coeval occurrences described in eastern Nigerian. Sm–Nd data together with the whole rock geochemical data suggest that: (I) the monzogranites were generated by partial melting of tonalitic gneiss from the lower crust, leaving behind a granulitic residue; (II) the diorites originated by partial melting of an enriched lithospheric mantle; (III) the evolution of the Solânea Complex involved magma mixing between the monzogranites and diorites. K-feldspar and amphibole fractionation appear to have occurred during the evolution of the monzogranites.Leucogranites constituting an elliptical shaped intrusion (80 km²), the Dona Inês Pluton, are intruded to the north of the Solânea Complex. They also occur as small intrusions cross-cutting the border of the Solânea Complex. Geochemical and isotopic data suggest that the leucogranites were generated by melting of crustal Palaeoproterozoic rocks. Rb–Sr data gave an age of 544 ± 16 Ma.Trans-alkaline magmatism is associated with ductile–brittle deformation in the Serrinha–Pedro Velho Complex of the São José do Campestre Massif. This event follows the peak of an extensional-related high-temperature metamorphism (upper amphibolite to granulite facies), with estimated age of 578 to 574 Ma. If a pre-Gondwana reconstruction is considered, this event is seen to extend to the African side of Gondwana in eastern Nigeria.     

Wave observations from an array of directional buoys over the southern Brazilian coast

It is well known that the majority of buoy measurements are located around the US coast and along some Europeans countries. The lack of long-term and densely spaced in situ measurements in the Southern Hemisphere in general, and the South Atlantic in particular, hinders several investigations due to the lack of detailed metocean information. Here, we present an effort to overcome this limitation, with a dense network of buoys along the Brazilian coast, equipped with several meteorological and oceanographic sensors. Out of ten currently operational buoys, three are employed to present the main characteristics of waves in the Southern part of the network. For the first time, sensor characteristics and settings are described, as well as the methods applied to the raw wave data. Statistics and distributions of wave parameters, swell propagating events, comparison with a numerical model and altimeters and a discussion about the occurrence of freak waves are presented.     

Water tank and numerical model studies of flow over steep smooth two-dimensional hills

The present work investigates the role of different treatments of the lower boundary condition on the numerical prediction of flows over two-dimensional, smooth, steep hills. Four different law of the wall formulations are tested when a large recirculating region is formed on the lee side of the hill. Numerical implementation of the near-wall functions was made through a finite elements code. The standard κ–ε model was used to close the averaged Navier–Stokes equations. Results are validated through original data obtained in a water tank. Measurements resorted to laser Doppler anemometry. The experiment provide detailed data for the characterization of the reverse flow in the region between the separation and the reattachment points, with emphasis on the near wall region. The experimental wall shear stress distribution is compared with the results provided by the different laws of the wall showing good agreement. The numerical predictions are shown to vary markedly between different formulations.     

A comparison of seismic risk maps for Italy

National seismic risk maps are an important risk mitigation tool as they can be used for the prioritization of regions within a country where retrofitting of the building stock or other risk mitigation measures should take place. The production of a seismic risk map involves the convolution of seismic hazard data, vulnerability predictions for the building stock and exposure data. The seismic risk maps produced in Italy over the past 10 years are compared in this paper with recent proposals for seismic risk maps based on state-of-the-art seismic hazard data and mechanics-based vulnerability assessment procedures. The aim of the paper is to open the discussion for the way in which future seismic risk maps could be produced, making use of the most up-to-date information in the fields of seismic hazard evaluation and vulnerability assessment.     

Spatial modelling of commercial spaces in medium-sized cities

The pattern of commercial spaces in a city has never been the consequence of chance. Retailers have always searched for the ‘best location’, but the notion of what exactly constitutes the ‘best location’ has changed over the decades. It is no longer a question of being close-to-market. It depends on an amount of social, economic and even morphological aspects of urban life, not to mention intrinsic aspects of the retail sector itself, namely new types of stores, products and purchase and payment options. Consequently, the methods retailers have employed to determine ‘best location’ have also evolved, and today increasingly complex mathematical and geospatial models are in use. It should then be safe to assume that commercial geography has changed and therefore, commercial hierarchies need to be re-invented, or at least challenged. A current trend in the literature is revealing more than ever the influence of commerce in the spatial and morphological re-configuration of cities. Thus, the understanding of modern retail patterns may be a key issue in interpreting and regulating the processes of urban, social and economic development. Using as test-beds four Portuguese medium-sized cities, commercial and morphological data was collected, analysed and compared, applying spatial analysis techniques. Similar patterns were found between the four cities, which led to the proposal of two geospatial commercial distribution models, one for the city-centre and one for the suburbia. These models shed a new light on the structure of Portuguese medium-size cities, and may well be valid in other medium and small towns across Europe.     

Earthquake loss estimation of residential buildings in Pakistan

Pakistan is an earthquake-prone region due to its tectonic setting resulting in high hazard with moderate-to-strong ground motions and vulnerability of structures and infrastructures, leading to the loss of lives and livelihood, property damage and economic losses. Earthquake-related disaster in Pakistan is a regular and serious threat to the community; however, the country lack tools for earthquake risk reduction through early warning (pre-earthquake planning), rapid response (prompt response at locations of high risk) and pre-financing earthquake risk (property insurance against disaster). This paper presents models for physical damageability assessment and socioeconomic loss estimation of structures in Pakistan for earthquake-induced ground motions, derived using state-of-the-art earthquake loss estimation methodologies. The methodologies are being calibrated with the site-specific materials and structures response, whereas the derived models are tested and validated against recent observed earthquakes in the region. The models can be used to develop damage scenario for earthquakes (assess damaged and collapsed structures, casualties and homeless) and estimate economic losses, i.e., cost of repair and reconstruction (for a single earthquake event as well as all possible earthquakes). The models can provide help on policy- and decision-making toward earthquake risk mitigation and disaster risk reduction in Pakistan.     

Geochemical modelling of the tonalitic and trondhjemitic granulites from the Itabuna-Salvador-Curaçá Block,Bahia, Brazil

The studied tonalitic and trondhjemitic granulites are located in the SSE granulitic domain of the São Francisco craton, Bahia, Brazil, where they represent most of the southern part of the Archean and Paleoproterozoic Itabuna-Salvador-Curaçá Block (ISCB). Chemically, the tonalitic and trondhjemitic granulites belong to a low-K calc-alkaline suite; their REE patterns are steep with strong LREE/HREE fractionation and no significant Eu anomaly. Garnet-bearing mafic granulites that occur as enclaves in the tonalitic and trondhjemitic granulites were derived from basalts and/or gabbros of tholeiitic affinity. Geochemical modelling showed that the tonalitic and trondhjemitic granulites were produced by moderate fractional crystallization of an assemblage of hornblende and plagioclase, with subordinate amounts of magnetite, apatite, allanite and zircon. The garnet-bearing mafic granulites would be the source of the magmas that generated these rocks. Partial melting left a residue made up of plagioclase, garnet, orthopyroxene and hornblende.