Exotic accessory minerals in layered chromitites of the Campo Formoso complex (Brazil)
Fuente:
Redalyc
Saved in:
| Main Author: | |
|---|---|
| Format: | Artículo científico |
| Language: | en |
| Published: |
Universitat de Barcelona
2006
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1876482785756053504 |
|---|---|
| author | F. Zaccarini |
| author_facet | F. Zaccarini |
| contents | Exotic accessory minerals in layered chromitites of the Campo Formoso complex (Brazil) F. Zaccarini G. Garuti R.F. Martin Ciencias de la Tierra Pb Brazil Apatite Monazite Chromitites The Campo Formoso stratiform intrusive complex, in Bahia State, Brazil, considered to be of Paleoproterozoicage, consists of a tabular body of ultramafic rocks about 40 km long and 100-1100 m wide. Thick horizons ofchromitite are exploited and the deposits are the richest in Brazil. The complex was intruded by the Campo Formosocalc-alkaline batholith, emplaced by the result of the Transamazonian collision-related orogeny. The peridotitewas firstly thoroughly serpentinized, then affected by a renewed cycle of hydrothermal alteration as thebatholith cooled, leading in the roof zone to emerald mineralization around roof pendants. An even later influxof fluid led to the formation of talc, silica and carbonates, such that the ultramafic rocks were locally convertedto listwanite. The chromitite sequences are highly unusual in containing rather exotic minerals, such as monazite-(La), monazite-(Ce), apatite, galena, bismuthinite, antimony, and three unknown minerals of stoichiometryPbSb2, Pb6 Sb and PbSb4, all associated with the clinochlore. The latter phases may have formed duringhydrothermal activity in the system Pb-Sb. The presence of these exotic minerals in chromitite, which makesthis occurrence unique in the world, strongly support the hypothesis that the La, Ce, P, Pb, Bi and Sb weremetasomatically added to the Campo Formoso chromitite horizons by hydrothermal fluids emanating from thenearby Campo Formoso calc-alkaline batholith as it cooled. 2006 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50540404 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.4 Vol.4 |
| format | Artículo científico |
| id | redalyc_50540404 |
| institution | Redalyc |
| language | en |
| publishDate | 2006 |
| publisher | Universitat de Barcelona |
| spellingShingle | Exotic accessory minerals in layered chromitites of the Campo Formoso complex (Brazil) F. Zaccarini Ciencias de la Tierra Pb Brazil Apatite Monazite Chromitites Exotic accessory minerals in layered chromitites of the Campo Formoso complex (Brazil) F. Zaccarini G. Garuti R.F. Martin Ciencias de la Tierra Pb Brazil Apatite Monazite Chromitites The Campo Formoso stratiform intrusive complex, in Bahia State, Brazil, considered to be of Paleoproterozoicage, consists of a tabular body of ultramafic rocks about 40 km long and 100-1100 m wide. Thick horizons ofchromitite are exploited and the deposits are the richest in Brazil. The complex was intruded by the Campo Formosocalc-alkaline batholith, emplaced by the result of the Transamazonian collision-related orogeny. The peridotitewas firstly thoroughly serpentinized, then affected by a renewed cycle of hydrothermal alteration as thebatholith cooled, leading in the roof zone to emerald mineralization around roof pendants. An even later influxof fluid led to the formation of talc, silica and carbonates, such that the ultramafic rocks were locally convertedto listwanite. The chromitite sequences are highly unusual in containing rather exotic minerals, such as monazite-(La), monazite-(Ce), apatite, galena, bismuthinite, antimony, and three unknown minerals of stoichiometryPbSb2, Pb6 Sb and PbSb4, all associated with the clinochlore. The latter phases may have formed duringhydrothermal activity in the system Pb-Sb. The presence of these exotic minerals in chromitite, which makesthis occurrence unique in the world, strongly support the hypothesis that the La, Ce, P, Pb, Bi and Sb weremetasomatically added to the Campo Formoso chromitite horizons by hydrothermal fluids emanating from thenearby Campo Formoso calc-alkaline batholith as it cooled. 2006 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50540404 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.4 Vol.4 |
| title | Exotic accessory minerals in layered chromitites of the Campo Formoso complex (Brazil) |
| topic | Ciencias de la Tierra Pb Brazil Apatite Monazite Chromitites |
| url | https://www.redalyc.org/articulo.oa?id=50540404 |