⁴⁰Ar/³⁹Ar-chronologische und mineralogische Untersuchungen zur Sericitisierung von Plagioklasen VON KIRSCH ....ARKOSES DE MARICÁ ET D'AUTRES MARICAS DA GAMA VASCO The main lithological units which occur in the "Cabo Frio TectonicFragment" are orthogneisses and paragneisses. The orthogneisses have granitic-granodioritic-tonalitic compositions, with amphibolitic enclaves andintercalations and are cutted by granitic aplites. The paragneisses aremetapelites, with intercalations of amphibolite, quartzites and calc-silicaterocks, metamorphosed in upper amphibolite facies, in intermediate pressureconditions. Geochemically, the orthogneisses correspond to a metaluminoushigh-K calc-alkalic series, with monzogabbro, quartz-monzodiorite andmonzonite compositions. Otherwise, the petrography indicates a low-K calc-alkalic series, suggesting a pre-collisional granitoids series related to oceaniccrust subduction. A divergence between the compositions obtained by the petrography and geochemistry can be the result of problems in the analyses of alkalies. The amphibolites, associated to the orthogneisses, also present calc-alkalic metaluminous character, with basaltic and andesitic compositions,suggestive of orogenic emplacement. The paragneisses show compositionsvarying between lithoarenite and arkoses, with peraluminous character, probably deposited in a continental arc or ative continental marginenvironment MORRA VASCUS VON GAMA MORRA PIM ...ESCREVE-SE PIM OU PIN Ó PIMPIM .... Publicat per Para a Posteridade e mais Além a 10:43 Envia per correu electrònic BlogThis! Comparteix a Twitter Comparteix a Facebook Comparteix a Pinterest Etiquetes de comentaris: bordejando a escarpa sudeste da Serra dos Órgãos limites da região anômala, entre Maricá e Macaé, que será denominada informalmente "Fragmento Tectônico Cabo Frio

Contribution à l'étude de l'altération du mica muscovite dans les schistes sériciteux

ALTERAÇÃO HIPOGÉNICA 

MONTMORILONITE  DEPOIS DA PLAGIOCLASE 

ARGÍLICA AVANÇADA INDICA CONTACTO 

COM FLUIDOS QUENTES 150 A 350ºC 

DE pH MUY BAIXO 

RESÍDUOS INSOLÚVEIS ENRIQUECIDOS

COM ALUMÍNIO E MINERAIS ALUMINOSOS 

CAULINITE PIROFILITE QUARTZO TAMBÉM APARECE

SERICITIZAÇÃO...MOSCOVITE E OUTROS SOVIETES 

MINERALIZADOS COMO A CUNHALITE 

PROPILÍTICA ....EPÍDOTO....E PI DO TÓ