Locality Attributes and Networks Serving to Reveal Amazonian Urbanization beyond the Cities     

Ana Paula Dal'Asta  Silvana Amaral 《Geographical review》2019,109(2):199-223

Beyond the Amazonian cities, distinct spatial units arranged in networks compose an extended urban space, usually invisible to government agencies and public polities. This article empirically reveals this space by studying the localities’ characteristics and connections. In southwestern Pará, Brazil, 236 communities were sampled using field expeditions. Variables related to the locality organization, history, health and education services, urban infrastructure, and land use were explored in a fuzzy cluster analysis. Local production and consumption flows were considered in the locality network analysis. The fuzzy analysis allowed identifying a hierarchy of localities for which the geographical location influences the spatial distribution patterns of five groups. On the other hand, consumption and production networks identified different locality's articulations, with persistent dependence on cities. These results characterize extensive urbanization at the local level and highlights the participation of the local populations configuring the Amazonian territory.  相似文献   

New triaromatic steroids distinguish Paleozoic from Mesozoic oil     

Silvana M. Barbanti  J. Michael MoldowanDavid S. Watt  E. Kolaczkowska 《Organic Geochemistry》2011,42(4):409-424

Certain biomarkers in petroleum provide information on of the geologic age of its source rock and these can also be used to track the evolution, radiation and relationships between taxa and as proxies for paleoenvironmental reconstruction. Triaromatic 23,24-dimethylcholesteroids (TA-DMC), which undoubtedly derive from 23,24-dimethylcholesterols in dinoflagellates, haptophytes and diatoms, provide a useful parameter to distinguish Paleozoic from Mesozoic and younger oil and rock extracts at higher specificity than previously proposed biomarkers. In this report, we present a study of the relative abundance of a novel series of TA-DMC in source rock extracts and crude oil from different global localities and ages. Based on their taxon specificity for important primary producers, such biogeochemicals also have implications for paleoenvironmental studies, including paleoclimate and global change, such as radiations following the Permian-Triassic boundary mass extinction.  相似文献   

Detrital zircon U–Pb ages and whole-rock geochemistry of the Neoproterozoic Paulistana and Santa Filomena complexes,Borborema Province,northeastern Brazil: implications for source area composition,provenance, and tectonic setting     

Felipe H. Santos  Wagner S. Amaral  Evilarde C. Uchôa Filho  Douglas T. Martins 《International Geology Review》2017,59(15):1861-1884

The Paulistana and Santa Filomena Complexes are situated in the southern part of the Borborema Province (northeastern Brazil), in the Riacho do Pontal Orogen, and represent meta-volcano-sedimentary sequences. We present compositional variations in the metasedimentary rocks and new U–Pb detrital zircon data. Major and trace elements indicate that the metasedimentary rocks from the Paulistana and Santa Filomena Complexes are composed mostly of immature to mature sediments derived from felsic-intermediate sources with moderate to slightly high chemical weathering. The geochemical signatures of the sediment protoliths for both complexes are characteristic of continental magmatic arc settings with minor contribution from recycled sediment sources. The source area for the Paulistana Complex rocks follow the compositional trend between calc-alkaline granites and granodiorites, whereas the Santa Filomena Complex rocks have a more restricted composition trending to more granodioritic sources. For the Paulistana Complex, two main source ages were identified: (1) Tonian (ca. 950 Ma – sample RPE-58) and Tonian–Stenian (ca. 1.0 Ga – sample RPE-103). These data coupled with geochemical information suggest that the Cariris Velhos arc system was the main source area for the Paulistana Complex. Regarding the Santa Filomena metasedimentary rocks, potential source-areas include: (1) Neoarchaean rocks (~2.6 Ga) represented by the adjacent basement rocks of the Riacho do Pontal Orogen; (2) Rhyacian–Orosirian rocks (2.2–2.0 Ga) of the Riacho do Pontal Orogen and the Pernambuco–Alagoas terrain, which include an augen-gneiss with arc-related geochemical signature; (3) Statherian granites (1.7–1.6 Ga); and (4) Cariris Velhos crust (1000–920 Ma). The metasedimentary rocks of the Paulistana Complex were deposited in a rift stage (ca. 900 Ma), which is related to the break-up of the Rodinia supercontinent. The metasedimentary rocks of the Santa Filomena Complex most probably were deposited in another rift stage (ca. 750–700 Ma) and could be correlatives of the rift formation of the Canindé Domain (Sergipano Orogen).  相似文献   

Relationship between volcanic ash fallouts and seismic tremor: quantitative assessment of the 2015 eruptive period at Cotopaxi volcano,Ecuador     

Benjamin Bernard  Jean Battaglia  Antonio Proaño  Silvana Hidalgo  Francisco Vásconez  Stephen Hernandez  Mario Ruiz 《Bulletin of Volcanology》2016,78(11):80

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QuakeIST<Superscript>®</Superscript> earthquake scenario simulator using interdependencies     

Francisco Mota de Sá  Mónica Amaral Ferreira  Carlos Sousa Oliveira 《Bulletin of Earthquake Engineering》2016,14(7):2047-2067

Earthquakes are a permanent threat to urban environments worldwide. The communication of the related risk demands accurate damage model simulations and an interactive visualization of results. The aim of this paper is to provide a realistic problem-solving environment for earthquake discussions among decision makers, stakeholders, and the general public. QuakeIST^® is an integrated earthquake simulator developed by Instituto Superior Técnico (Lisbon University), oriented towards the performance of risk calculations concerning damage propagations that use the Disruption Index concept. This software imports data stored in a GIS environment, handles different ground motion scenarios, and deals with a complex situation of different soils and vulnerabilities of various layers of civil structures (buildings, lifelines, and other urban structures). It models interdependencies between several infrastructures and between infrastructures and the urban tissue. The computer programme is very versatile, written in separate modules, allowing an experimented user to incorporate new formulations. Results can be treated with any statistical application and most common GIS commercial environments can produced their geographic visualization. Current progress and new upcoming are briefly described at the end of the paper.  相似文献   

GEOGRAPHY IN MEXICO     

Jerry P. Schofer  Silvana Levi  Efrain Pena Villada  Andrzej M. Zeronski 《The Professional geographer》1990,42(3):380-382

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Effects of vegetation and sewage load on mangrove crab condition using experimental mesocosms     

Valter Amaral  Gil Penha-Lopes  José Paula 《Estuarine, Coastal and Shelf Science》2009

Constructed wetlands, especially mangroves, have been studied for their usefulness in sewage treatment but the effects of mangrove vegetation and a sewage load on mangrove macrofauna have been given little attention. Ocypodid crabs are important components of mangrove forests and constitute good bioindicators of the functioning of the ecosystem as a whole. In constructed mangrove mesocosms, three vegetation treatments (bare substratum, and Avicennia marina and Rhizophora mucronata seedlings) were subjected to 0, 20, 60 and 100% sewage loads from a nearby hotel. The physiological condition of introduced Uca annulipes and Uca inversa was evaluated in terms of their RNA/DNA ratio after one, five and twelve months, and used as an indicator of ecological function in the system. Crab condition in 0% sewage load was similar to that of wild crabs throughout, suggesting no significant effects of the mesocosms on their RNA/DNA ratio. Overall, both species coped well with the administered sewage loads, suggesting good ecological function in the system. Both species manifested similar patterns in RNA/DNA ratio, being more affected by seasonal fluctuations than by sewage load and vegetation presence and type. Higher RNA/DNA ratios were recorded in the long compared to the short rainy season. Sewage enhanced crab condition in the bare substratum and R. mucronata treatments, especially after one year, probably as a result of enhanced food availability. Uca inversa may be more sensitive to sewage pollution than U. annulipes. In A. marina, no difference in crab condition was observed between sewage loads, and this mangrove yielded the best reduction in sewage impacts. Our results support the usefulness of constructed mangrove areas in sewage treatment, especially if planted with A. marina and inhabited by physiologically healthy ocypodid crabs to enhance the system's performance.  相似文献   

New Early Cretaceous palaeomagnetic pole from Córdoba Province (Argentina): revision of previous studies and implications for the South American database     

Silvana E. Geuna  & Haroldo Vizán† 《Geophysical Journal International》1998,135(3):1085-1100

A continental sequence of red beds and interbedded basaltic layers crops out in the Sierra Chica of Córdoba Province, Argentina (31.5°S, 64.4°W). This succession was deposited in a half-graben basin during the Early Cretaceous. We have carried out a palaeomagnetic survey on outcrops of this basin (147 sites in seven localities). From an analysis of IRM acquisition curves and detailed demagnetization behaviour, three different magnetic components are identified in the volcanic rocks: components A, B and X are carried by single- or pseudo-single-domain (titano) magnetite, haematite and multidomain magnetite, respectively. Component A is interpreted as a primary component of magnetization because it passes conglomerate, contact, tilt and reversal tests. The carrier of the primary magnetization, fine-grained (titano)magnetite, is present in basalts with a high degree of deuteric oxidation. This kind of oxidation is interpreted to have occurred during cooling. Components B and X are discarded because they are interpreted as recent magnetizations. In the sedimentary rocks, haematite and magnetite are identified as the carriers of remanence. Both minerals carry the same component, which passes a reversal test. The calculated palaeomagnetic pole, based on 55 sites, is Lat. 86.0°S, Long. 75.9°E ( A ₉₅=3.3, K =35). This palaeomagnetic pole supersedes four with anomalous positions reported in previous papers.  相似文献   

Delicious guinea pigs: Seasonality studies and the use of fat in the pre-Columbian Andean diet     

Silvana A. Rosenfeld   《Quaternary International》2008,180(1):127

In the Nearctic ecozone (temperate, subarctic, and arctic environments) hunter–gatherers often have to rely on diets with inadequate caloric intakes during certain times of the year. Although the Neotropic ecozone has different and less extreme conditions, it can also be nutritionally challenging. While the tropical forests offer a more stable diet (in terms of carbohydrates, proteins, and fat availability), high altitude biomes, such as the central Andes, can challenge human populations to metabolize proteins properly in certain times of the year. Guinea pigs (Cavia porcellus) may have been incorporated in the Andean diet because they represented an additional source of fat, especially when carbohydrates were short in supply.  相似文献   

Focal mechanism inversion in the Giudicarie–Lessini seismotectonic region (Southern Alps, Italy): Insights on tectonic stress and strain     

Alfio Vigan  Gianni Bressan  Giorgio Ranalli  Silvana Martin 《Tectonophysics》2008,460(1-4):106-115

A set of 41 focal mechanisms (1989–2006) from P-wave first polarities is computed from relocated seismic events in the Giudicarie–Lessini region (Southern Alps). Estimated hypocentral depths vary from 3.1 to 20.8 km, for duration magnitudes (M_D) in the range 2.7–5.1. Stress and strain inversions are performed for two seismotectonic zones, namely G (Giudicarie) and L (Lessini). This subdivision is supported by geological evidence, seismicity distribution, and focal mechanism types. The available number of data (16 in G, 22 in L) does not make possible any further subdivisions. Seismotectonic zones G and L are undergoing different kinematic regimes: thrust with strike-slip component in G, and strike-slip in L. Principal stress and strain axes in each sub-region show similar orientations. The direction of maximum horizontal compressive stress is roughly perpendicular to the thrust fronts along the Giudicarie Belt in zone G, and compatible with right-lateral strike-slip reactivation of the faults belonging to the Schio-Vicenza system in zone L. On the whole, kinematic regimes and horizontal stress orientations show a good fit with other stress data from focal mechanisms and breakouts and with geodetic strain rate axes.  相似文献