Matches in SemOpenAlex for { <https://semopenalex.org/work/W69875174> ?p ?o ?g. }
Showing items 1 to 61 of
61
with 100 items per page.
- W69875174 endingPage "38" @default.
- W69875174 startingPage "11" @default.
- W69875174 abstract "The present investigation seeks to study the areas with ornamental/dimension stone potential in the Esmolfe and Antas-Matanca granitic massif, in central northern Portugal. Both granites studied are calc-alkaline, undeformed, blue-grey in colour, medium-grained with a slightly porphyritic tendency. The textural characteristics of the granite massifs are relatively homogeneous although variations do occur. The Antas-Matanca facies shows some colour variations and heterogeneity in grain size. The Esmolfe facies is more homogeneous, coarser-grained, and lighter in colour, due to aggregates of feldspar crystals, than the Antas-Matanca facies. Superficial alteration of the Antas-Matanca facies is greater than in the Esmolfe facies. Due to the petrographic and textural characteristics of the granite under study, and small defects in terms of dimension stone production, the main limiting factor in defining favourable areas for dimension stone extraction is the fracture density pattern. Hence, this aspect is highlighted. In the Esmolfe massif, the main fracture orientation is N15-30o W (total population). In this system, 50% of the fracture spacing is < 1m although there is considerable dispersion. The total fracture population in the Antas-Matanca massif shows there to be two main orientation directions 40-50o and 150-160o that are sub vertical in nature. In both sets spacing is < 1m (65% of total). Fracture spacing in both massifs are considered moderate (1-2.5m) to ample (2.5-6.25m). Comparison of the class frequencies of distance between consecutive fractures shows that the distribution of intervals is similar in both the Esmolfe and Antas-Matanca massifs. However, if we compare the average distance frequencies between fractures in the scanlines, the spacing between fractures in Esmolfe appears to be greater than in Antas-Matanca. In Esmolfe, one third of the lines studied, the average spacing is < 2m. These factors, in conjunction with the textural homogeneity of the rock, mineralogical characteristics and other factors, such as favourable topographic conditions, easy access and large reserves demonstrate the high ornamental potential of these granites. The quarrying activity in Esmolfe is intense and chaotic which causes a high negative visual impact. The lack of technical management in the majority of quarries implies that rarely the more promising levels are ever 1 1 e Daniel P. S. de Oliveira Jose Vitor Lisboa Cadernos Lab. Xeoloxico de Laxe Coruna. 2005. Vol. 30, pp. 11-38 extracted resulting in the premature closure of the quarry. The Esmolfe granite is commercialised under various designations of which Cinza (grey) is the more common. It outcrops generally in large boulders that due to their dimension alone allow the installation of the quarries. Alteration profile is generally < 0.2m. The extraction activity of the Antas-Matanca massif is presently restricted to three quarries, being the granite commercialised under the designation Cinza (grey) or Cinzento Antas (Antas grey). The existence of extensive slabs of this facies with a reduced alteration profile creates very favourable conditions for dimension stone extraction. This study shows that the Esmolfe massif has potential for extraction in four areas located SW of Pedras Altas and S of Ponte do Ferreira. For the Antas-Matanca massif 5 areas are proposed, namely the outcrops nearby Pisao, Lameira area (station A24), Antas and Abrocedo areas. The importance of this study is clearly shown not only for territorial land planning uses, in the selection and hierarchisation of potential areas but also to better plan exploration methodologies (e.g. use of georadar or percussion drilling), if the raw material warrants it." @default.
- W69875174 created "2016-06-24" @default.
- W69875174 creator A5043105159 @default.
- W69875174 creator A5074593695 @default.
- W69875174 date "2005-01-01" @default.
- W69875174 modified "2023-09-27" @default.
- W69875174 title "Granitos de Esmolfe e Antas-Matança (Portugal): petrografia e influência da fracturação no estabelecimento de áreas potenciais para exploração de granito ornamental" @default.
- W69875174 hasPublicationYear "2005" @default.
- W69875174 type Work @default.
- W69875174 sameAs 69875174 @default.
- W69875174 citedByCount "1" @default.
- W69875174 countsByYear W698751742013 @default.
- W69875174 crossrefType "journal-article" @default.
- W69875174 hasAuthorship W69875174A5043105159 @default.
- W69875174 hasAuthorship W69875174A5074593695 @default.
- W69875174 hasConcept C109007969 @default.
- W69875174 hasConcept C114614502 @default.
- W69875174 hasConcept C114793014 @default.
- W69875174 hasConcept C127313418 @default.
- W69875174 hasConcept C142362112 @default.
- W69875174 hasConcept C144024400 @default.
- W69875174 hasConcept C146588470 @default.
- W69875174 hasConcept C149923435 @default.
- W69875174 hasConcept C151730666 @default.
- W69875174 hasConcept C15708023 @default.
- W69875174 hasConcept C160776313 @default.
- W69875174 hasConcept C17409809 @default.
- W69875174 hasConcept C199289684 @default.
- W69875174 hasConcept C2779670319 @default.
- W69875174 hasConcept C2779870107 @default.
- W69875174 hasConcept C2908647359 @default.
- W69875174 hasConcept C33923547 @default.
- W69875174 hasConcept C66882249 @default.
- W69875174 hasConceptScore W69875174C109007969 @default.
- W69875174 hasConceptScore W69875174C114614502 @default.
- W69875174 hasConceptScore W69875174C114793014 @default.
- W69875174 hasConceptScore W69875174C127313418 @default.
- W69875174 hasConceptScore W69875174C142362112 @default.
- W69875174 hasConceptScore W69875174C144024400 @default.
- W69875174 hasConceptScore W69875174C146588470 @default.
- W69875174 hasConceptScore W69875174C149923435 @default.
- W69875174 hasConceptScore W69875174C151730666 @default.
- W69875174 hasConceptScore W69875174C15708023 @default.
- W69875174 hasConceptScore W69875174C160776313 @default.
- W69875174 hasConceptScore W69875174C17409809 @default.
- W69875174 hasConceptScore W69875174C199289684 @default.
- W69875174 hasConceptScore W69875174C2779670319 @default.
- W69875174 hasConceptScore W69875174C2779870107 @default.
- W69875174 hasConceptScore W69875174C2908647359 @default.
- W69875174 hasConceptScore W69875174C33923547 @default.
- W69875174 hasConceptScore W69875174C66882249 @default.
- W69875174 hasIssue "30" @default.
- W69875174 hasLocation W698751741 @default.
- W69875174 hasOpenAccess W69875174 @default.
- W69875174 hasPrimaryLocation W698751741 @default.
- W69875174 isParatext "false" @default.
- W69875174 isRetracted "false" @default.
- W69875174 magId "69875174" @default.
- W69875174 workType "article" @default.