Minerais de ferro do Ordovícico Inferior do Anticlinal de Valongo
The Lower Ordovician oolitic ironstones of Valongo anticline have abundant chamosite and/or siderite. True oolites are rare in the studied levels. Some pseudo-oolites are related to the presence of algae, as evidenced by cathodoluminescence. Iron came from emerged areas and deposited during transgre...
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| Formato: | article |
| Idioma: | por |
| Publicado em: |
2011
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| Texto completo: | https://hdl.handle.net/10216/52536 |
| País: | Portugal |
| Oai: | oai:repositorio-aberto.up.pt:10216/52536 |
| Resumo: | The Lower Ordovician oolitic ironstones of Valongo anticline have abundant chamosite and/or siderite. True oolites are rare in the studied levels. Some pseudo-oolites are related to the presence of algae, as evidenced by cathodoluminescence. Iron came from emerged areas and deposited during transgression of Early Ordovician, in a shallow platform protected by barriers, with exhalativesedimentary vent in reducing environment rich in organic matter |
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