Léxico Estratigráfico do Brasil |
| Unidade: | PEDRA BRANCA 2, Arenito |
| Idade: | Devoniano |
| UF: | GO, |
| Termo(s): | ND, |
| Local tipo: | Rio Tocantis a jusante de Tupiratins, estado de Goiás. |
| Autor(es): | MOORE, B., 1963; |
| Citação Original: | |
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The three main lithological types are described in the Stratigraphic Summary and presented diagramatically in the Composite Stratigraphic column. The most distinctive features of the upper "pedra branca" sandstone are the poorly sorted angular grains, the mica content and the white kaolonitic matrix. The "tillite" zone consiste of polygenic unsorted, possibly striated inclusions in an unstratified clayey sand matrix. The basal sandstone contains gritty bands but generally is finer grained and bether sorted than the upper horizon. A detailed analysis of Cabeças sandstone grain sizes is included in Appendix III. (Pág. 28). |
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| Comentário: | |
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MOORE, op. cit., descreve o Arenito Pedra Branca da seguinte forma: "Sandstone, pedra branca"; off-white, medium to coarse grained, poor to fair sorting, angular or sub-angular, arkosic, seattered black tourmaline grains; matrix light gray, kaolinitic, micro-micaceous, powdery, scattered large angular quartz granules and small pebbles medium bedding, cross-bedded. |
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| Bibliografia: | |
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MOORE, B. Geological reconnaissance of the South West corner of the Maranhão basin. Belém, PETROBRÁS, 1963. 79. Inédito. |
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| Compilador: | |
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Milton Brand Baptista (CPRM) |
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