scholarly journals The Troia–Pedra Branca mafic–ultramafic complex, Borborema Province, Brazil: Record of 2.04 Ga post–collisional Alaskan–type magmatism and PGE mineralization

2021 ◽  
Vol 4 (2) ◽  
pp. 147-178
Author(s):  
Felipe Grandjean da Costa ◽  
◽  
Wagner Amaral ◽  
Hector Barrueto ◽  
João Naleto ◽  
...  
Keyword(s):  
Borborema Province ◽  
Pge Mineralization ◽  
Ultramafic Complex

Tsumoite (BiTe) and associated Ni-PGE mineralization from Gondpipri mafic-ultramafic complex, Bastar Craton, Central India: mineralogy and genetic significance

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
M. Dora ◽  
H. Singh ◽  
A. Kundu ◽  
M. Shareef ◽  
K. Randive ◽  
...  
Keyword(s):  
Total Concentration ◽  
Central India ◽  
Olivine Gabbro ◽  
Pge Mineralization ◽  
Ultramafic Complex ◽  
Mineral Assemblages ◽  
Hydrothermal Remobilization ◽  
Two Stages ◽  
Host Rocks

AbstractThis paper reports the occurrence of Tsumoite (a bismuth telluride) in the Heti Cu-Ni-PGM prospect, Gondpipri mafic-ultramafic complex, Central India. The Gondpipri complex consists of several tectonically dismembered gabbronorite-gabbro-anorthositic gabbro — olivine gabbro -websterite disposed in ∼10 km long tonalite-trondhjemitegranodiorite (TTG) and charnockite-enderbite suite of rocks. The mineralization occurs in the sulphide zone hosted by gabbro variants. The host rocks have been deformed and metamorphosed to granulite grade and subjected to various degrees of hydrothermal alteration. The mineralization comprises chalcopyrite, pentlandite, pyrrhotite, cubanite, millerite, and pyrite. In addition to these, occur (1) tsumoite (2) PGM in the form of moncheite, merenskyite, Pd-mellonite, and Pt-Pd-Te-Bi-Fe-S alloy.The present study indicates that the mineralization occurs in two stages related to: (i) magmatic and (ii) hydrothermal remobilization and transport of Cu-rich sulphides, tsumoite and PGM, and their re-deposition in hydrosilicate alteration zones. It is possible that the mineralization at Heti formed at different stages of bismuth activity under variable fS2, T, and fTe2 conditions due to change in total concentration of Te and S and /or cooling. Since the role of S is limited, Te and cooling are important factor influencing mineralogy and composition of tsumoite and associated mineralization. Mineralization occurs in two different modes of occurrences. The early mineralisation occur as blebs, specks and dissemination of sulphides, viz. pyrrhotite, chalcopyrite, pentlandite and minor pyrite ± PGM, whereas later mineralisation occur as stringers, minor veins of sulphides viz. pyrite, millerite, cubanite, sijenite, tsumoite and ± PGM.Mineral assemblages and textural relationships at Heti has indicated precipitation of tsumoite and associated PGM along fractures and secondary silicates, which confirms their hydrothermal origin.

Alaskan-type nature and PGE mineralization of the Wuxing mafic–ultramafic complex in eastern part of the Central Asian Orogenic belt

2020 ◽  
Vol 123 ◽  
pp. 103566
Author(s):  
Meng-Meng Cui ◽  
Ben-Xun Su ◽  
Jing Wang ◽  
Kai-Yun Chen ◽  
Patrick Asamoah Sakyi ◽  
...  
Keyword(s):  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Central Asian ◽  
Pge Mineralization ◽  
Ultramafic Complex

PETROLOGICAL AND GEOCHEMICAL CHARACTERIZATION OF THE SAN JUAN DE OTATES ULTRAMAFIC COMPLEX, LEÓN, GUANAJUATO: TECTONIC IMPLICATIONS

2020 ◽  
Author(s):  
Nathalia Pineda rodriguez ◽  
◽  
Vanessa Colás ◽  
Vanessa Colás ◽  
José María González-Jiménez ◽  
...  
Keyword(s):  
San Juan ◽  
Geochemical Characterization ◽  
Tectonic Implications ◽  
Ultramafic Complex

Unraveling sedimentary precursors and metal enrichment of high-grade metamorphosed manganese-rich rocks from the Borborema Province, northeastern Brazil

2021 ◽  
pp. 104283
Author(s):  
Felipe Holanda dos Santos ◽  
Wagner da Silva Amaral ◽  
Kurt Konhauser ◽  
Douglas Teixeira Martins ◽  
Marco Paulo de Castro ◽  
...  
Keyword(s):  
Northeastern Brazil ◽  
High Grade ◽  
Metal Enrichment ◽  
Borborema Province

scholarly journals Decratonization by rifting enables orogenic reworking and transcurrent dispersal of old terranes in NE Brazil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Carlos E. Ganade ◽  
Roberto F. Weinberg ◽  
Fabricio A. Caxito ◽  
Leonardo B. L. Lopes ◽  
Lucas R. Tesser ◽  
...  
Keyword(s):  
Shear Zones ◽  
Boundary Region ◽  
The North ◽  
Pan African ◽  
Juvenile Material ◽  
Oceanic Basin ◽  
Borborema Province ◽  
Isotopic Model ◽  
Late Neoproterozoic

AbstractDispersion and deformation of cratonic fragments within orogens require weakening of the craton margins in a process of decratonization. The orogenic Borborema Province, in NE Brazil, is one of several Brasiliano/Pan-African late Neoproterozoic orogens that led to the amalgamation of Gondwana. A common feature of these orogens is that a period of extension and opening of narrow oceans preceded inversion and collision. For the case of the Borborema Province, the São Francisco Craton was pulled away from its other half, the Benino-Nigerian Shield, during an intermittent extension event between 1.0–0.92 and 0.9–0.82 Ga. This was followed by inversion of an embryonic and confined oceanic basin at ca. 0.60 Ga and transpressional orogeny from ca. 0.59 Ga onwards. Here we investigate the boundary region between the north São Francisco Craton and the Borborema Province and demonstrate how cratonic blocks became physically involved in the orogeny. We combine these results with a wide compilation of U–Pb and Nd-isotopic model ages to show that the Borborema Province consists of up to 65% of strongly sheared ancient rocks affiliated with the São Francisco/Benino-Nigerian Craton, separated by major transcurrent shear zones, with only ≈ 15% addition of juvenile material during the Neoproterozoic orogeny. This evolution is repeated across a number of Brasiliano/Pan-African orogens, with significant local variations, and indicate that extension weakened cratonic regions in a process of decratonization that prepared them for involvement in the orogenies, that led to the amalgamation of Gondwana.

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