Search results for "BELT"
showing 10 items of 204 documents
Vestiges of the Mesoproterozoic Events in the Neoproterozoic Mozambique Belt: the East African Perspective in the Rodinia Puzzle
2003
Abstract Most of the geological and palaeogeographical models consider the Neoproterozoic supercontinent Gondwana (∼650-550 Ma) as the direct offspring of the disintegrated Mesoproterozoic supercontinent Rodinia (∼1300-750 Ma). One of the main classical sutures along which the dispersing Rodinia fragments were fused into a new supercontinent (Godwana) is identified as the Mozambique belt of East Africa. The calc-alkaline magmatism (∼1200-950 Ma) in northern Mozambique, southern Malawi and southern Tanzania is regarded as the sole evidence for fragmentation of Rodinia, which is traced within this Neoproterozoic orogenic belt. There are no unequivocal Mesoproterozoic (Kibaran) sediments in th…
Shear-zone patterns and eclogite-facies metamorphism in the Mozambique belt of northern Malawi, east-central Africa: implications for the assembly of…
2002
Abstract We report on the first occurrence of Pan-African eclogite from the Mozambique belt of northern Malawi, east-central Africa. We describe aspects of (1) the pattern of Pan-African transcurrent and subhorizontal shear zones and how these shear zones relate to eclogite-facies metamorphism and (2) the P – T – t evolution of the eclogite. Finally, we discuss the significance of eclogite-facies metamorphism and shear-zone deformation for the assembly of Gondwana. The first major deformation event involved sinistral and dextral transcurrent and top-ESE shearing and occurred at ∼580–550 Ma. Transcurrent and top-ESE shearing resulted from ESE–WNW horizontal crustal shortening and commenced u…
Pan-African granulite formation in the Kabye Massif of northern Togo (West Africa): Pb−Pb zircon ages
2000
Metamorphic zircons from seven granulite facies orthogneisses of tonalitic composition (ender- bites), collected from four different nappes of the Kabye Massif in the Dahomeyide belt of northern Togo, were dated by the Pb-Pb evaporation method. They yielded consistent Neoproterozoic ages with a mean of 612.5 0.8 Ma, interpreted to reflect the peak of regional granulite facies metamorphism following Pan-African continental collision between the West African and Benin-Nigerian plates. These results sup- port previous ages obtained by various chronometers on high-grade rocks from the same suture zone and from surrounding units in Togo, Benin and Ghana. They are also similar to zircon ages fr…
The Argille Varicolori Unit of Lucania (Italy): a record offscraping and gravity sliding in the Mesozoic-Tertiary Lagonegro Basin, southern Apennines
2006
Detailed geological mapping and new stratigraphic and structural data collected in the Lucania area of the southern Apennines allowed us to assess the deformation history of 11 Monte-Corleto Perticara zone, in the High Agri Valley (Lucanian Apennines, southern Italy) where red and green shales (known as Argille Varicolori or Argille scagliose) crop out. Our observations suggest that: (1) 'chaotic' facies within the Argille Varicolori may be attributed to a broken formation generated by overthrusting of Apenninic Platform units onto already deformed Lagonegro basin strata; (2) gravity sliding phenomena at the thrust front enhanced the development of debris flow and the emplacement of olistos…
Connecting Existing Cemeteries Saving Good Soils (for Livings)
2019
Background: Urban sprawl consumes and degrades productive soils worldwide. Fast and safe decomposition of corpses requires high-quality functional soils, and land use which competes with both agriculture and buildings. On one hand, cremation does not require much land, but it has a high energy footprint, produces atmospheric pollution, and is unacceptable to some religious communities. On the other hand, as exhumations are not practiced, “green burials” require more surface area than current burial practices, so a new paradigm for managing land use is required. Conclusions: In this paper, we propose a concept for ‘green belt communalities’ (i.e., ecological corridors with multiple, yet flex…
New Perspectives on Ecological Networks
2017
This chapter introduces the theme of ecological networks, exploring the reference theoretical bases within the International academic debate, and proposing a reflection on how protected areas should no longer be considered as the sum of different components, but rather as a network. In relation to this aspect, the transnational and national models of ecological networks, carried out in the different European countries, are analyzed, through a detailed, updated study of relevant national and international documents. Particular attention is given to the European ecological Natura 2000 network that constitutes the official framework for European policies on protected natural areas. The work hi…
Transport planning as suggested in John Claudius Loudon’s 1829 plan for London
2017
ABSTRACTWe consider Scottish landscape gardener J.C. Loudon’s already well-documented 1829 plan for a system of successive green belts around London. Our perspective will be that of transport planning, given his recommendations on street layout and public transport provision. Our contention is that Loudon’s design for the Metropolis would have been theoretically inoperative if it had not been for its transport network. Beside other forward-thinking aspects already demonstrated by researchers, Loudon’s plan is remarkable for setting out a design for an integrated Metropolis based on road planning and the then barely nascent technology of railways.
On Lp resolvent estimates for Laplace–Beltrami operators on compact manifolds
2014
In this article we prove Lp estimates for resolvents of Laplace–Beltrami operators on compact Riemannian manifolds, generalizing results of Kenig, Ruiz and Sogge (1987) in the Euclidean case and Shen (2001) for the torus. We follow Sogge (1988) and construct Hadamard's parametrix, then use classical boundedness results on integral operators with oscillatory kernels related to the Carleson and Sjölin condition. Our initial motivation was to obtain Lp Carleman estimates with limiting Carleman weights generalizing those of Jerison and Kenig (1985); we illustrate the pertinence of Lp resolvent estimates by showing the relation with Carleman estimates. Such estimates are useful in the constructi…
Historical Origins of the nine-point conic -- The Contribution of Eugenio Beltrami
2020
In this paper, we examine the evolution of a specific mathematical problem, i.e. the nine-point conic, a generalisation of the nine-point circle due to Steiner. We will follow this evolution from Steiner to the Neapolitan school (Trudi and Battaglini) and finally to the contribution of Beltrami that closed this journey, at least from a mathematical point of view (scholars of elementary geometry, in fact, will continue to resume the problem from the second half of the 19th to the beginning of the 20th century). We believe that such evolution may indicate the steady development of the mathematical methods from Euclidean metric to projective, and finally, with Beltrami, with the use of quadrat…
The N Variscan margin of the Ruhr coal district (Western Germany): structural style of a buried thrust front?
1988
The Ruhr coal district represents part of an external fold and thrust belt of the Variscan orogen in central Europe. Extensive mining exposed molasse-type, coal-bearing clastic sequences of Upper Carboniferous age, deformed by folding and thrusting. Thrusts range in scale from decameters to 40 kilometers along strike but displacements are below 2.5 km. They are distributed in various stratigraphic levels and no regional detachment horizon is exposed. Displacement is mainly towards NW (towards the foreland) but also towards SE. The thrusts are bound to stockwerk-tectonics and die out towards depth frequently antithetic to the exposed strata. Folds vary in wavelength from decameters to more t…