Encontrados 3 documentos, a visualizar página 1 de 1
The provenance of Late Ediacaran and Early Ordovician siliciclastic rocks in th...
Pereira, M.F.; Linnemann, U.; Hofmann, M.; Chichorro, M.; Solá, A.R; Medina, J.; Silva, J.B.U–Pb geochronology of detrital zircon from Late Ediacaran (Beiras Group greywackes) and Early Ordovician (Sarnelhas arkosic quartzites and Armorican quartzites of Penacova) sedimentary rocks of the southwest Central Iberian Zone (SW CIZ) constrain the evolution of northern Gondwana activepassive margin transition. The LAICPMS U–Pb data set (375 detrital zircons with 90–110% concordant ages) is dominated by Neop...
North-Gondwana assembly, break-up and paleogeography: U–Pb isotope evidence fro...
Pereira, M.F.; Solá, A.R.; Chichorro, M.; Lopes, L.; Gerdes, A.; Silva, J.B.The Estremoz Anticline in the Ossa-Morena Zone (SW Iberia) includes upper Ediacaran detrital rocks uncon- formably overlain by lower Cambrian detrital and carbonate rocks. The spectra of detrital zircon U–Pb ages dominated by Cryogenian and Ediacaran ages (with a typical gap in Mesoproterozoic ages) of the upper Edi- acaran greywackes and lower Cambrian arkosic sandstones indicate provenance from sources placed...
Different meanings for cummingtonite-hornblende association in plutonic rocks (...
Solá, A. R.; Moita, P.; Santos, J. F.; Neiva, A. M. R.; Ribeiro, M. L.Cummingtonite-grunerite series is frequently related with metamorphism or volcanic environments but rarely described as belonging to a plutonic assemblage [1]. Recently, in Iberian Massif (Portugal), there have been several references [2,3,4,5] of this Fe-Mg amphibole intimately associated with Ca amphiboles (mainly hornblende) on plutonic rocks. Different textural relations between two amphibole types have bee...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||