Pre-vegetation fluvial floodplains and channel-belts in the Late Neoproterozoic–Cambrian Santa Bárbara group (Southern Brazil)

2014 ◽  
Vol 300 ◽  
pp. 49-61 ◽  
Author(s):  
André Marconato ◽  
Renato Paes de Almeida ◽  
Bruno Boito Turra ◽  
Antônio Romalino dos Santos Fragoso-Cesar
Keyword(s):  
Southern Brazil ◽  
Santa Barbara ◽  
Late Neoproterozoic

Santa Bárbara Formation (Early Paleozoic, Caçapava do Sul, southern Brazil): Petrographic and Sm–Nd isotopic provenance parameters

2008 ◽  
Vol 26 (4) ◽  
pp. 485-497 ◽  
Author(s):  
André Weissheimer de Borba ◽  
Ana Maria Pimentel Mizusaki ◽  
Anderson José Maraschin ◽  
Diogo Rodrigues Andrade da Silva
Keyword(s):  
Early Paleozoic ◽  
Southern Brazil ◽  
Santa Barbara

scholarly journals Late sodic metasomatism evidences in bimodal volcanic rocks of the Acampamento Velho Alloformation, Neoproterozoic III, southern Brazil

2007 ◽  
Vol 79 (4) ◽  
pp. 725-737 ◽  
Author(s):  
Delia Del Pilar M. de Almeida ◽  
Vitor P. Pereira ◽  
Adriane Machado ◽  
Henrique Zerfass ◽  
Ricardo Freitas
Keyword(s):  
Volcanic Rocks ◽  
Alkali Feldspar ◽  
Southern Brazil ◽  
Santa Barbara ◽  
Crystallization Sequence ◽  
Mafic Rocks ◽  
Mineralogical Study ◽  
Felsic Volcanic ◽  
Felsic Volcanic Rocks ◽  
Felsic Rocks

A mineralogical study was carried out in mafic and felsic volcanic rocks of the Acampamento Velho Alloformation at Cerro do Bugio, Perau and Serra de Santa Bárbara areas (Camaquã Basin) in southern Brazil. The Acampamento Velho bimodal event consists of two associations: lower mafic at the base and upper felsic at the top. Plagioclase and alkali-feldspar were studied using an electronic microprobe, and magnetite, ilmenite, rutile, illite and alkali-feldspar were investigated through scanning electron microscopy. The rocks were affected by a process of late sodic autometasomatism. In mafic rocks, Ca-plagioclase was transformed to albite and pyroxenes were altered. In felsic rocks, sanidine was partially pseudomorphosed, generating heterogeneous alkali-feldspar. In this association, unstable Ti-rich magnetite was replaced by rutile and ilmenite. In mafic rocks, the crystallization sequence was: (1) Ti-rich magnetite (?), (2) pyroxene and Ca-plagioclase, (3) albite (alteration to Ca-plagioclase), (4) sericite, chlorite and calcite (alteration to pyroxene), and kaolinite (alteration to plagioclase/albite). In felsic rocks: (1) zircon, (2) Ti-rich magnetite, (3) sanidine, (4) quartz. The introduction of late Na-rich fluids, generated the formation of (5) heterogeneous alkali-feldspar, (6) ilmenite and rutile from the Ti-rich magnetite, (7) albite in the spherulites. Finally, alteration of sanidine, vitroclasts and pumice to (8) illite.

The role of post-collisional strike-slip tectonics in the geological evolution of the late Neoproterozoic volcano-sedimentary Guaratubinha Basin, southern Brazil

2017 ◽  
Vol 80 ◽  
pp. 29-46 ◽  
Author(s):  
Leonardo M. Barão ◽  
Barbara Trzaskos ◽  
Fernando F. Vesely ◽  
Luís Gustavo de Castro ◽  
Francisco J.F. Ferreira ◽  
...  
Keyword(s):  
Strike Slip ◽  
Southern Brazil ◽  
Geological Evolution ◽  
Late Neoproterozoic

Validation of a screening instrument for postpartum depression in Southern Brazil

2009 ◽  
pp. 1-11
Author(s):  
Carlos Zubaran ◽  
Katia Foresti ◽  
Marina Verdi Schumacher ◽  
Aline Luz Amoretti ◽  
Lucia Cristina Muller ◽  
...  
Keyword(s):  
Postpartum Depression ◽  
Screening Instrument ◽  
Southern Brazil
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