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| Format: | Artículo científico |
| Language: | en |
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Academia Brasileira de Ciências
2007
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| Online Access: | https://www.redalyc.org/articulo.oa?id=32779213 |
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| _version_ | 1866815435958124544 |
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| author | Gislaine Amorés Battilani |
| author_facet | Gislaine Amorés Battilani |
| contents | The occurrence of microdiamonds in Mesoproterozoic Chapada Diamantina intrusive rocks - Bahia / Brazil Gislaine Amorés Battilani Newton S. Gomes Wilson J. Guerra Multidisciplinaria (Ciencias Naturales y Exactas) microdiamonds intrusive rocks Mesoproterozoic Tombador Formation Serra do Espinhaço The origin of diamonds from Serra do Espinhaço in Diamantina region (State of Minas Gerais) and in Chapada Diamantina,Lençóis region (State of Bahia) remains uncertain, even taking into account the ample research carried outduring the last decades. The lack of typical satellite minerals in both districts makes a kimberlitic source for thesediamonds uncertain. In mid 18th century the occurrence of a metamorphosed igneous rock composed of martite,sericite and tourmaline was described in Diamantina region and named hematitic phyllite, considered by some researchersas a possible diamond source. Similar rocks were found in Lençóis and examined petrographically and theirheavy mineral concentration was investigated by means of scanning electron microscopy (SEM). Petrographic analysesindicated an igneous origin for these rocks and SEM analyses showed the discovery of microdiamonds. Geochronologicalstudies using the Ar/Ar technique in muscovites yielded minimum ages of 1515 ± 3 Ma, which may correlatewith 1710 ± 12 Ma from U-Pb method in igneous zircons from the hematitic phyllites. Both rock types also have thesame mineral and chemical composition which leads to the conclusion that the intrusive rocks were protolith of thehematitic phyllites. This first discovery of microdiamonds in intrusive rocks opens the possibility of new investigationmodels for diamond mineralization in Brazilian Proterozoic terrains 2007 artículo científico 0001-3765 https://www.redalyc.org/articulo.oa?id=32779213 en http://www.redalyc.org/revista.oa?id=327 Anais da Academia Brasileira de Ciências application/pdf Academia Brasileira de Ciências Anais da Academia Brasileira de Ciências (Brasil) Num.2 Vol.79 |
| format | Artículo científico |
| id | redalyc_32779213 |
| language | en |
| publishDate | 2007 |
| publisher | Academia Brasileira de Ciências |
| spellingShingle | The occurrence of microdiamonds in Mesoproterozoic Chapada Diamantina intrusive rocks - Bahia / Brazil Gislaine Amorés Battilani Multidisciplinaria (Ciencias Naturales y Exactas) microdiamonds intrusive rocks Mesoproterozoic Tombador Formation Serra do Espinhaço The occurrence of microdiamonds in Mesoproterozoic Chapada Diamantina intrusive rocks - Bahia / Brazil Gislaine Amorés Battilani Newton S. Gomes Wilson J. Guerra Multidisciplinaria (Ciencias Naturales y Exactas) microdiamonds intrusive rocks Mesoproterozoic Tombador Formation Serra do Espinhaço The origin of diamonds from Serra do Espinhaço in Diamantina region (State of Minas Gerais) and in Chapada Diamantina,Lençóis region (State of Bahia) remains uncertain, even taking into account the ample research carried outduring the last decades. The lack of typical satellite minerals in both districts makes a kimberlitic source for thesediamonds uncertain. In mid 18th century the occurrence of a metamorphosed igneous rock composed of martite,sericite and tourmaline was described in Diamantina region and named hematitic phyllite, considered by some researchersas a possible diamond source. Similar rocks were found in Lençóis and examined petrographically and theirheavy mineral concentration was investigated by means of scanning electron microscopy (SEM). Petrographic analysesindicated an igneous origin for these rocks and SEM analyses showed the discovery of microdiamonds. Geochronologicalstudies using the Ar/Ar technique in muscovites yielded minimum ages of 1515 ± 3 Ma, which may correlatewith 1710 ± 12 Ma from U-Pb method in igneous zircons from the hematitic phyllites. Both rock types also have thesame mineral and chemical composition which leads to the conclusion that the intrusive rocks were protolith of thehematitic phyllites. This first discovery of microdiamonds in intrusive rocks opens the possibility of new investigationmodels for diamond mineralization in Brazilian Proterozoic terrains 2007 artículo científico 0001-3765 https://www.redalyc.org/articulo.oa?id=32779213 en http://www.redalyc.org/revista.oa?id=327 Anais da Academia Brasileira de Ciências application/pdf Academia Brasileira de Ciências Anais da Academia Brasileira de Ciências (Brasil) Num.2 Vol.79 |
| title | The occurrence of microdiamonds in Mesoproterozoic Chapada Diamantina intrusive rocks - Bahia / Brazil |
| topic | Multidisciplinaria (Ciencias Naturales y Exactas) microdiamonds intrusive rocks Mesoproterozoic Tombador Formation Serra do Espinhaço |
| url | https://www.redalyc.org/articulo.oa?id=32779213 |