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| Calsteren, P.W.C. van. |
| High beat-flow foci on the Earth have been named ‘hot-spots’ and are commonly correlated with ‘mantle-plumes’ in the deep. A mantle plume may be described as a portion of mantle material with a higher heat content than its surroundings. The intrusion of a mantle-plume is inferred to be similar to the intrusion of a salt diapir and the process of diapirism is discussed. The theoretical mechanistic and thermal effects of hot diapirs and the tectonic and metamorphic implications are discussed. Two sets of diapirs, i.e. a first order diapir equal to a mantle-plume and, originating from it, second order diapirs causing hot spots, are invoked to give a reasonable explanation for the Palaeozoic evolution of the continental lithosphere of Western Galicia (NW... |
| Tipo: Article / Letter to the editor |
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| Ano: 1981 |
URL: http://www.repository.naturalis.nl/record/506019 |
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| Arps, C.E.S.; Calsteren, P.W.C. van; Hilgen, J.D.; Kuijper, R.P.; Tex, E. den. |
| In Galicia occur several polymetamorphic complexes that contain mafic and ultramafic rocks. Mafic volcanics and gabbros are situated in or near the complexes. An episode of metamorphism and granitization encompassed the generation of the volcanics and gabbros. Gravity surveys revealed the existence of deep roots below polymetamorphic complexes. Geochronological investigations yielded Palaeozoic ages from about 500 Ma for the generation of ultramafic rocks and calcalkaline granite series, till ages of around 300 Ma for postkinematic alkaline and calcalkaline granites. A model involving mantle-plume diapirism and rejuvenation of the lower crust is proposed for the Early Palaeozoic evolution of the continental lithosphere of Galicia. An excursion route is... |
| Tipo: Article / Letter to the editor |
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| Ano: 1978 |
URL: http://www.repository.naturalis.nl/record/505595 |
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| Calsteren, P.W.C. van. |
| Mafic and ultramafic rocks from a high-grade complex at Cabo Ortegal in NW Spain were investigated in the field and in the laboratory by means of petrological, isotope-geochronological and geochemical methods. Isotope-geochronological methods were applied to orthogneisses from a high-grade complex near Mellid and from the blastomylonitic graben between Malpica and Tuy, a mica-bearing eclogite lens from the same graben, and to a two-mica granite from the area near La Guardia. A gravity survey was carried out in part of the belt of sub-circular complexes surrounding the Ordenes basin. The geochronological investigations revealed ages of about 500 Ma to 320 Ma for older elements in the Hercynian basement of Galicia. Geochemical investigations in the Cabo... |
| Tipo: Article / Letter to the editor |
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| Ano: 1978 |
URL: http://www.repository.naturalis.nl/record/505688 |
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| Calsteren, P.W.C. van. |
| This catalogue contains information on the meteorite collections presently on display or on storage in The Netherlands. It is organized in three separate listings. The first and shortest listing gives the meteorite names grouped according to their classification. The second listing is the main body of this catalogue and gives the meteorite names in alphabetical order with specific information on place and date of fall or find, classification, chemical and structural composition, registration number and weight. This information is mainly based on the 'Catalogue of Meteorites' by Hey (1966) and the 'Appendix to the Catalogue of Meteorites' by Hutchison, Bevan & Hall (1977). The third listing gives the meteorite names and their classification grouped... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 39.54. |
| Ano: 1979 |
URL: http://www.repository.naturalis.nl/record/317503 |
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