Mahyra Tedeschi

Federal University of Minas Gerais | UFMG · Departamento de Geologia

The investigation of key minerals including zircon, apatite, titanite, rutile, monazite, xenotime, allanite, baddeleyite and garnet can retain critical information about petrogenetic and geodynamic processes and may be utilised to understand complex geological histories and the dynamic evolution of the continental crust. They act as small but often...

Deciphering the provenance of paraderived rocks that underwent high-to ultrahigh (HT-UHT) temperature metamorphism is a challenging task. Such metamorphic conditions can generate protracted zircon U–Pb age records of unclear meaning. However, the combination of U–Pb and Lu–Hf in zircon geochronology might be used as a powerful tool in order to retr...

Free download before September 21, 2023, on (https://authors.elsevier.com/c/1hWat3BkFSZ~A4) By comparison with igneous rock assemblages of well-exposed modern magmatic arcs and their typical calc-alkaline, magnesian, I-type signatures, many deeply eroded magmatic arcs have been characterized worldwide, unraveling ancient plate margins. Since the 19...

Detrital heavy minerals have helped address geologically complex issues such as the nature and origin of the early terrestrial crust, the growth and evolution of the continental crust, as well as the onset of plate tectonics, together with paleogeographic reconstructions and supercontinent cycles. With the advent of in situ analytical techniques an...

The study of magmatic and metamorphic processes is challenged by geological complexities like geochemical variations, geochronological uncertainties, and the presence/absence of fluids and/or melts. However, by integrating petrographic and microstructural studies with geochronology, geochemistry, and phase equilibrium diagrams investigations of dif...

The ultra-high pressure metamorphic rocks of the West Gondwana Orogen are the earliest evidence of deep subduction on Earth. The West Gondwana Orogen resulted from the closure of the Pharusian-Goianides Ocean in the Late Neoproterozoic, leading to the formation of the Santa Quitéria Continental Magmatic Arc (SQCMA) in NE Brazil and the Forquilha Ec...

The structural framework of the Alto Pajeú Terrane, Borborema Province (NE Brazil) records a complex tectonic evolution related to the Neoproterozoic amalgamation of Western Gondwana. Combined, multiscale geophysical and litho-structural datasets for the Central Borborema Province constrain the regional crustal architecture. Magnetic and radiometri...

Key minerals, including zircon, apatite, titanite, rutile, monazite, xenotime, allanite and garnet, can retain critical information about petrogenetic and geodynamic processes. This Special Publication showcases snapshots of the latest developments using key minerals in igneous, metamorphic and detrital rocks through current-state reviews, contribu...

Orógenos colisionais funcionam como cápsulas do tempo que podem registrar grandes eventos geológicos que ocorreram durante a evolução da Terra. A reconstituição dos diferentes estágios de tais eventos depende, entretanto, de uma série de fatores, como a composição favorável do protólito e as condições de preservação. A reconstrução de trajetórias P...

The assessment of detrital zircon age records is a key method in basin analysis, but it is prone to several biases imposing isotopic disturbances that may compromise accurate sedimentary provenance investigations. High to ultrahigh temperature (HT-UHT) metamorphism (especially if > 850 °C) is herein presented as a natural cause of bias in provenanc...

Unraveling the tectonic evolution of Precambrian high-grade rocks is often challenging owing to widespread metamorphic overprint under high to ultra-high temperature conditions. These situations require the use of isotopic methods. We present a petrochronological investigation using U–Pb, and Lu–Hf data of zircon grains extracted from a biotite-bea...

Abstract can be found at http://dx.doi.org/10.46427/gold2022.8849

Deciphering the tectono-metamorphic evolution of Precambrian terranes can be difficult due to reworking by later superimposed events. Whole-rock elemental and isotopic geochemistry and zircon U-Pb geochronology are often employed in those studies, but these approaches are often not sensitive to the presence of multiple events and medium-grade metam...

We present the first evidence of Archean oceanic crust submitted to Proterozoic high-pressure (HP) metamorphism in the South American Platform. Sm-Nd and Lu-Hf isotopic data combined with U-Pb geochronological data from the Campo Grande area, Rio Grande do Norte domain, in the Northern Borborema Province, reflect a complex Archean (2.9 Ga and 2.6 G...

Two arc systems have been described within the Neoproterozoic Ribeira Belt: the inner continental magmatic arc and the outer intra-ocean magmatic arc. New geochemical and U-Pb and Lu-Hf (LA-ICPMS) data from zircons of the Marceleza-Leopoldina stocks, belonging to the inner magmatic arc system, in the boundary region between the Ribeira and Araçuaí...

A systematic investigation of amphibolites and a metaultramafite granofels was carried out in the southernmost Brasília Orogen, part of the reworked margin of the São Francisco paleocontinent. These rocks occur interleaved within Neoproterozoic metasediments and the Archean-Paleoproterozoic basement. The amphibolites from the Andrelândia, Liberdade...

The investigation of ultrahigh temperature (UHT) metamorphic rocks, and their corresponding (pressure)-temperature-time (P-T-t) history is critical to distinguish between arc- or collision-related metamorphism. This is a very challenging task if mineral assemblages are highly retrogressed and isotopic systems are disturbed. Garnet-free granulites l...

Assembled during the Rhyacian-Orosirian boundary, the Congo-São Francisco palaeocontinent remained linked by a continental bridge from ca. 2 Ga to the Atlantic Ocean opening in the Cretaceous. To the south of that bridge, precursor basins and orogenic outcomes encompassed by the Neoproterozoic-Cambrian Araçuaí-Ribeira orogenic system (AROS) and its...

The identification of markers of subduction zones in orogenic belts requires the estimation of paleo-geothermal gradients through pressure-temperature-time (P-T-t) estimates in mafic rocks that potentially derive from former oceanic units once. However, such markers are rare in supracrustal sequences specially in deeply eroded and weathered Pre...

Este volume consiste de um estudo detalhado da região do médio rio Jequitinhonha, parte da Província Pegmatítica Oriental do Brasil, situada no nordeste de Minas Gerais, principal área produtora e detentora das reservas de lítio do Brasil, além de conter também um levantamento bibliográfico de outras áreas com ocorrências de minerais de lítio no pa...

Described half a century ago, the Galiléia tonalite represents a milestone in the discovery of plate margin magmatic arcs in the Araçuaí-Ribeira orogenic system (southeastern Brazil). In the 1990’s, analytical studies on the Galiléia tonalite finally revealed the existence of a Late Neoproterozoic calc-alkaline magmatic arc in the Araçuaí orogen. M...

The Araçuaí orogen of southeastern Brazil together with the West Congo belt of central West Africa form the Araçuaí-West Congo orogen generated during closure of a terminal segment of the Neoproterozoic Adamastor Ocean. Corresponding to an embayment in the São Francisco-Congo Craton, this portion of the Adamastor was only partially floored by ocean...

A região englobada pelas folhas Caldas e Poços de Caldas localiza-se no lobo setentrional da nappe Socorro-Guaxupé. Esta constitui uma pilha alóctone interpretada como representante do arco magmático Paranapanema, compondo parte do sistema de nappes do Orógeno Brasília Meridional cavalgado sobre o Cráton do São Francisco durante a Orogenia Brasilia...

The Araçuaí orogen (SE Brazil) together with its counterpart located in Africa, the West Congo belt, represent a confined orogenic edifice, which evolved inside an embayment shaped into the São Francisco–Congo palaeocontinent. This embayment was partially floored by oceanic crust, as indicated by the occurrence of Late Cryogenian to Ediacaran ophio...

A Folha Andrequicé (SE.23-Z-A-I) localiza-se na porção central de Minas Gerais, setor centro-sul da Bacia do São Francisco. O mapeamento geológico na escala 1:100.000 permitiu a individualização, da base para o topo, das formações Córrego dos Borges (MPcb), Jequitaí (NP1j), Serra de Santa Helena (NP3sh), Lagoa do Jacaré (NP3lj), Serra da Saudade (N...