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| Meerbeke, G.L.E. van; Hilgen, J.D.; Floor, P.. |
| Probably Lower Paleozoic quartzo-pelitic schists with bands of feldspathic schists, white and black quartzites, graphite schists and amphibolites have been folded twice. Hercynian regional metamorphism led to porphyroblastic growth of chlorite, albite, biotite, garnet, staurolite mainly between F1 and F2. Andalusite porphyroblasts are related to Hercynian granite intrusions of varying age with respect to F2. An isograd map of biotite, garnet, staurolite and andalusite is presented. Structures elucidating the relations between deformation phases and metamorphic mineral growth are discussed. |
| Tipo: Article / Letter to the editor |
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| Ano: 1973 |
URL: http://www.repository.naturalis.nl/record/505769 |
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| Floor, P.. |
| The investigated area forms part of the crystalline basement of the southwestern half of the Iberian peninsula (Hesperian Massif). In it, Precambrian paragneisses of predominantly greywacke composition surround granite-gneisses with whole-rock Rb-Sr ages of 486-500 m.y. Hercynian granites are intrusive into the older rocks. It is argued that the paragneisses underwent a Barrovian type regional metamorphism (probably low P-T portion of the almandine-amphibolite facies) in the Precambrian, were locally thermometamorphosed by some types of the Cambro-Ordovician granite complex, while in the hercynian orogeny they were again subjected to regional metamorphism, but now of the Abukuma-type (andalusite-cordierite-muscovite subfacies of cordierite-amphibolite... |
| Tipo: Article / Letter to the editor |
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| Ano: 1967 |
URL: http://www.repository.naturalis.nl/record/505786 |
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| Floor, P.. |
| A review is given of pre-hercynian metasediments and granites (including per-alkaline aegirineriebeckite granites) found in W. Galicia. These rocks were subsequently deformed and metamorphosed by the hercynian orogeny. Evidence in favour of the existence of a pre-hercynian metamorphism that affected the metasediments is presented. Some special relations between granite-gneisses and metasediments, e.g., the development of thermo-metamorphic aureoles around some pre-hercynian granites and the influence of sodium-metasomatism from riebeckite gneiss upon rocks surrounding them are discussed. La presente contribución trata exclusivamente de las regiones investigadas por la Escuela de Leiden, menos la zona de Cabo Ortegal descrita por D. E. Vogel en una... |
| Tipo: Article / Letter to the editor |
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| Ano: 1967 |
URL: http://www.repository.naturalis.nl/record/505825 |
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