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dc.contributor.authorFoucaud, Yann
dc.contributor.authorFilippov, Lev
dc.contributor.authorLechenard, Bénédicte
dc.contributor.authorMarion, Philippe
dc.date.accessioned2021-06-02T10:11:06Z
dc.date.available2021-06-02T10:11:06Z
dc.date.issued2018
dc.identifierONIX_20210602_10.5772/intechopen.71674_387
dc.identifier.urihttps://library.oapen.org/handle/20.500.12657/49273
dc.description.abstractThe Tabuaço tungsten deposit (Northern Portugal) is hosted in the Cambrian Douro Group metasediments, at the northern margin of the Beira-Tabuaço granitic complex. The hosting schisto-calcareous Lower Cambrian Bateiras Formation underwent a contact metamorphism induced by the intrusion of the granitic complex. The skarnification led to the crystallisation of scheelite (CaWO4). Two different skarn facies are encountered: ‘Lower Skarn’ and ‘Main Skarn’ both corresponding to the exoskarn. The ‘Main Skarn’ is mainly composed of vesuvianite (Ca10Mg2Al4(SiO4)5(Si2O7)2(OH)4), feldspars and fluorite. Zoisite, grossular, fluorapatite and scheelite are also present, as well as malayaite and cassiterite. Scheelite is disseminated and often occurs in association with fluorite, albite and vesuvianite. The ‘Lower Skarn’ level contains predominantly diopsidic pyroxene, quartz, zoisite, grossular and feldspars. Scheelite appears both laminated and disseminated, in association with fluorite and vesuvianite in minor proportions. The ‘Main Skarn’ is located in the Garnet, Pyroxene zone, while the ‘Lower Skarn’ corresponds to the Pyroxene, Garnet zone. Pyroxene has a global hedenbergite Hd40 composition. A major phase of albitisation destabilised fluorite, scheelite, vesuvianite, garnet and pyroxene. A late stage of chloritisation is associated with the exhumation. The processing of the Tabuaço ore has been adapted to the Ca-bearing rich paragenesis and to the scheelite mean size.
dc.languageEnglish
dc.subject.classificationthema EDItEUR::P Mathematics and Science::PN Chemistry::PNV Chemistry of minerals, crystals and gemsen_US
dc.subject.otherskarn, scheelite, texture, paragenesis, processing
dc.titleChapter Geology, Textural Study, Ore Genesis and Processing of the Tabuaço Tungsten Deposit (Northern Portugal)
dc.typechapter
oapen.identifier.doi10.5772/intechopen.71674
oapen.relation.isPublishedBy09f6769d-48ed-467d-b150-4cf2680656a1
oapen.relation.isFundedByH2020-SC5-2014-one-stage
oapen.grant.number641650
oapen.grant.acronymFAME


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