Anatexia de crosta inferior e média e geração de granitos na Nappe de Empurrão Socorro-Guaxupé, SE do Brasil uma síntese preliminar

Janasi, Valdecir de Assis; Vasconcellos, A. C. B. C.

doi:10.11606/issn.2317-8078.v0i18p63-65

Cited by 1 publication

(1 citation statement)

References 3 publications

(3 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Temperatures over 950 C are due to mangerite intrusions, which were emplaced in the southern part of the study area. These mangerite magmas probably caused re-equilibration of the mineral parageneses during their emplacement (Janasi and Vasconcellos 1996). Campos Neto and Caby (1999) estimated P±T conditions of 900 C and 12 kbar followed by partial re-equilibration at 850 C and 7.5 kbar.…”

Section: Geological Settingmentioning

confidence: 99%

Exhumation of high‐pressure granulites of the Guaxupé Complex, southeastern Brazil

Lama¹,

Zanardo

Oliveira

et al. 2000

Geological Journal

View full text Add to dashboard Cite

This paper describes tectonic and metamorphic features of Precambrian rocks from the Guaxupe Â Complex and Varginha Shear Zone (VSZ) near the city of Guaxupe Â in the southern part of the Sa Äo Francisco Craton, southeastern Brazil. The VSZ separates the metasediments of Araxa Â Group to the north from the granulites of Guaxupe Â Complex to the south. The sinistral transcurrent VSZ crosses the entire area striking approximately E±W, bending towards SE in the eastern part. Because of this bend, transpressional movement occurred, facilitating the exhumation of the garnet-rich rocks of the deepest exposed part of the granulitefacies terrane.In the garnet granulites the highest pressure±temperature conditions recorded are approximately 1040 C and 14.4 kbar. The rocks underwent decompression from 14.0 kbar to 8.0 kbar, cooling from 980 C to 710 C, the retrograde path following the boundary between the kyanite and sillimanite stability ®elds. This interval is interpreted to record the uplift of the lower crustal granulite-facies terrane and re-equilibration during magmatic intrusions. For the felsic granulites an interval of 700±810 C and 8.0±11.5 kbar was attained, also pointing to regional decompression.The granulites of the Guaxupe Â Complex comprise a medium-to high-pressure lower-crustal terrane, with local occurrences of higher-pressure garnet-rich gneisses, which were uplifted along a transpressional segment of the VSZ. Figure 1. Schematic geological map and location of the research area (adapted from Fonseca et al. 1979).232e. a. del lama et al.

show abstract

Section: Geological Settingmentioning

confidence: 99%