Registros magmáticos extensionais e colisionais no Terreno Apiaí, sul-sudeste do Brasil: integração de dados U-PB - Zircão

The aim of this work is the presentation of a synthesis of available geochronological data for the basement inliers and metavolcano-sedimentary sequences which occur in the southern part of the Apiaí Terrane, south-southeastern Brazil. These data, especially those obtained during the last decade, have made substantial modifications to the tectonic scenario of south-southeastern Brazil with the recognition of the presence of extensional basins (continental rifts) with magmatism and sedimentation at the late Paleoproterozoic (1790 - 1750 Ma) and of the Mesoproterozoic (1600 - 1450 Ma). These processes started at the late Paleoproterozoic in the Betara, Perau and Apiai Mirim Nuclei, and the basins became widerduring the Mesoproterozoic with the deposition of the Betara, Perau, Votuverava and Água Clara metavolcano-sedimentary sequences. A different pattern is found for the Itaicoca Sequence which occupies the northern part of the Apiaí Terrain. Here two rock associations of different ages are found. The first is a metamorphosed carbonate platform association with subalkaline, tholeiitic metabasic rocks with minimum deposition ages at the end of the Mesoproterozoic or beginning of the Neoproterozoic (Itaiacoca Sequence; 1030 - 900 Ma), while the second mainly contains metapsammites and metavolcanic rocks including ultrapotassic trachytes deposited during the Cryogenian-Ediacaran transition between 645 and 628 Ma (Abapã Sequence). It is then proposed that the present scenario of the Apiaí Terrane be representative of the distinct tectono-sedimentary histories, reflecting a polycyclic evolution. In the Mesoproterozoic, stable conditions prevailed, withthe deposition of the majority of the sequences (Lajeado, Água Clara, Betara, Perau, Votuverava) in a passive margin context, succeded by a Tonian extensional phase (deposition of the Itaiacoca Sequence). In the Ediacaran the region was transformed into an unstable active margin, with the predominance of magmatic arcs (Três Córregos, Cunhaporanga and Agudos Grandes) and restricted sedimentation (Abapã, Antinha and Iporanga Sequences).O principal objetivo deste trabalho é apresentar uma síntese dos dados geocronológicos disponíveis para as sequências metavulcano-sedimentares e núcleos de embasamento que ocorrem na porção sul do Terreno Apiaí, sul-sudeste do Brasil. Os dados obtidos, principalmente na última década, têm modificado substancialmente o cenário tectônico do sul-sudeste brasileiro, identificando a presença de bacias extensionais (rifts continentais) com magmatismo e sedimentação associada do final do Paleoproterozoico (1790 - 1750 Ma) e do Mesoproterozoico (1600 - 1450 Ma). O desenvolvimento desses processos parecem ter se iniciado no final do Paleoproterozoico (Núcleos Betara, Perau e Apiaí Mirim), evoluindo para bacias mais amplas durante o Mesoproterozoico com a deposição das sequências metavulcanossedimentares Betara, Perau, Votuverava e Água Clara. Padrão distinto é observado para a Sequência Itaiacoca, que ocupa a porção setentrional do Terreno Apiaí. O estudo geológico-geocronológico caracterizou a existência de dois conjuntos litológicos temporalmente distintos, o primeiro representado por uma associação plataformal metacarbonática, que inclui rochas metabásicas de natureza toleítica/subalcalina, com idades mínimas de deposição relacionadas ao final do Mesoproterozoico/início do Neoproterozoico (Sequência Itaiacoca: 1.030-900 Ma). O segundo conjunto é representado principalmente por rochas metapsamíticas com metavulcânicas associadas, incluindo traquitos ultrapotássicos, depositados na transição Criogeniano/Ediacarano (Sequência Abapã: 645-628 Ma). O presente cenário sugere histórias tectono-sedimentares distintas para o Terreno Apiaí, refletindo uma evolução policíclica. Durante o Mesoproterozoico predominaram condições relativamente estáveis com a deposição de grande parte das sequências metavulcanossedimentares (Lajeado, Água Clara, Betara, Perau, Votuverava), num contexto de margem passiva, sucedidos pela deposição da Sequência Itaiacoca, associada a regimes extensionais do Toniano. No Ediacarano prevaleceram condições instáveis, de margem ativa, caracterizadas por restrita sedimentação (Sequências Abapã, Antinha e Iporanga) e colocação dos batólitos graníticos Três Córregos, Cunhaporanga e Agudos Grandes, representantes de arcos magmáticos

Extensional and colisional magmatic records in the Apiai Terrane, south-southeastern Brazil: integration of geochronological U-Pb zircon ages

The aim of this work is the presentation of a synthesis of available geochronological data for the basement inliers and metavolcano-sedimentary sequences which occur in the southern part of the Apiai Terrane, south-southeastern Brazil. These data, especially those obtained during the last decade, have made substantial modifi cations to the tectonic scenario of south-southeastern Brazil with the recognition of the presence of extensional basins (continental rifts) with magmatism and sedimentation at the late Paleoproterozoic (1790 - 1750 Ma) and of the Mesoproterozoic (1600 - 1450 Ma). These processes started at the late Paleoproterozoic in the Betara, Perau and Apiai Mirim Nuclei, and the basins became wider during the Mesoproterozoic with the deposition of the Betara, Perau, Votuverava and gua Clara metavolcano-sedimentary sequences. A different pattern is found for the Itaicoca Sequence which occupies the northern part of the Apiai Terrain. Here two rock associations of different ages are found. The fi rst is a metamorphosed carbonate platform association with subalkaline, tholeiitic metabasic rocks with minimum deposition ages at the end of the Mesoproterozoic or beginning of the Neoproterozoic (Itaiacoca Sequence; 1030 - 900 Ma), while the second mainly contains metapsammites and metavolcanic rocks including ultrapotassic trachytes deposited during the Cryogenian-Ediacaran transition between 645 and 628 Ma (Abapa Sequence). It is then proposed that the present scenario of the Apiai Terrane be representative of the distinct tectono-sedimentary histories, refl ecting a polycyclic evolution. In the Mesoproterozoic, stable conditions prevailed, with the deposition of the majority of the sequences (Lajeado, gua Clara, Betara, Perau, Votuverava) in a passive margin context, succeded by a Tonian extensional phase (deposition of the Itaiacoca Sequence). In the Ediacaran the region was transformed into an unstable active margin, with the predominance of magmatic arcs (Tres Corregos, Cunhaporanga and Agudos Grandes) and restricted sedimentation (Abapa, Antinha and Iporanga Sequences)

Major shear zones of southern Brazil and Uruguay: escape tectonics in the eastern border of Rio de La plata and Paranapanema cratons during the Western Gondwana amalgamation

The Mantiqueira Province represents a series of supracrustal segments of the South-American counterpart formed during the Gondwana Supercontinent agglutination. In this crustal domain, the process of escape tectonics played a conspicuous role, generating important NE-N-S-trending lineaments. The oblique component of the motions of the colliding tectonic blocks defined the transpressional character of the main suture zones: Lancinha-Itariri, Cubato-Arcadia-Areal, Serrinha-Rio Palmital in the Ribeira Belt and Sierra Ballena-Major Gercino in the Dom Feliciano Belt. The process as a whole lasted for ca. 60 Ma, since the initial collision phase until the lateral escape phase predominantly marked by dextral and subordinate sinistral transpressional shear zones. In the Dom Feliciano Belt, southern Brazil and Uruguay, transpressional event at 630-600 Ma is recognized and in the Ribeira Belt, despite less coevally, the transpressional event occurred between 590 and 560 Ma in its northern-central portion and between ca. 625 and 595 Ma in its central-southern portion. The kinematics of several shear zones with simultaneous movement in opposite directions at their terminations is explained by the sinuosity of these lineaments in relation to a predominantly continuous westward compression.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP-Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[03/13246-6]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP-Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[04/07837-4]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP-Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[05/58688-1

Deformation and geochronology of syntectonic granitoids emplaced in the Major Gercino Shear Zone, southeastern South America

The Major Gercino Shear Zone is one of the NE-SW lineaments that separate the Neoproterozoic Dom Feliciano Belt, of Brazil and Uruguay, into two different domains: a northwestern supracrustal domain from a southeastern granitoid domain. The shear zone, striking NE, is composed of protomylonites to ultramylonites with mainly dextral kinematic indicators. In Santa Catarina State, southern Brazil, the shear zone is composed of two mylonite belts. The mylonites have mineral orientations produced under greenschist fades conditions at a high strain rate. Strong flattening and coaxial deformation indicate the transpressive character, while the role of pure shear is emphasized by the orientation of the mylonite belts in relation to the inferred stress field component. The quartz microstructures point out that different dynamic recrystallization regimes and crystal plasticity were the dominant mechanisms of deformation during the mylonitization process. Additionally, the fabrics suggest that the glide systems are activated for deformation conditions compatible with the metamorphism in the middle greenschist facies. Elongated granitoid intrusions belonging to two petrographically, geochemically and isotopically distinct rock associations occur between the two mylonite belts. The structures observed in the granites result from a deformation range from magmatic to solid-state conditions points to a continuum of magma straining during and just after its crystallization. Conventional U-Pb analysis of multi-crystal zircon fractions yielded essentially identical ages of 609 +/- 16 Ma and 614 +/- 2 Ma for the two granitic associations, and constrain the transpressive phase of the shear zone. K-Ar ages of biotites between 585 and 560 Ma record the slow cooling and uplift of the intrusions. Some K-Ar ages of micas in regional mylonites are similar, suggesting that thermo-tectonic activity was intense up to this time, probably related to the agglutination of the granite belt to the supracrustal belt NW of the MGSZ. (C) 2009 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.FAPESP[92/3729-3]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Extensional and Colisional Magmatic Records in the Apiaí Terrane, South-Southeastern Brazil: Integration of Geochronological U-Pb Zircon Ages

The aim of this work is the presentation of a synthesis of available geochronological data for the basement inliers andmetavolcano-sedimentary sequences which occur in the southern part of the Apiaí Terrane, south-southeastern Brazil.These data, especially those obtained during the last decade, have made substantial modifi cations to the tectonic scenarioof south-southeastern Brazil with the recognition of the presence of extensional basins (continental rifts) with magmatismand sedimentation at the late Paleoproterozoic (1790 - 1750 Ma) and of the Mesoproterozoic (1600 - 1450 Ma). Theseprocesses started at the late Paleoproterozoic in the Betara, Perau and Apiai Mirim Nuclei, and the basins became widerduring the Mesoproterozoic with the deposition of the Betara, Perau, Votuverava and Água Clara metavolcano-sedimentarysequences. A different pattern is found for the Itaicoca Sequence which occupies the northern part of the Apiaí Terrain.Here two rock associations of different ages are found. The fi rst is a metamorphosed carbonate platform association withsubalkaline, tholeiitic metabasic rocks with minimum deposition ages at the end of the Mesoproterozoic or beginning of theNeoproterozoic (Itaiacoca Sequence; 1030 - 900 Ma), while the second mainly contains metapsammites and metavolcanicrocks including ultrapotassic trachytes deposited during the Cryogenian-Ediacaran transition between 645 and 628 Ma(Abapã Sequence). It is then proposed that the present scenario of the Apiaí Terrane be representative of the distincttectono-sedimentary histories, refl ecting a polycyclic evolution. In the Mesoproterozoic, stable conditions prevailed, withthe deposition of the majority of the sequences (Lajeado, Água Clara, Betara, Perau, Votuverava) in a passive margincontext, succeded by a Tonian extensional phase (deposition of the Itaiacoca Sequence). In the Ediacaran the region wastransformed into an unstable active margin, with the predominance of magmatic arcs (Três Córregos, Cunhaporanga andAgudos Grandes) and restricted sedimentation (Abapã, Antinha and Iporanga Sequences)

Lower and Upper Neoproterozoic magmatic records in Itaiacoca Belt (Parana-Brazil): Zircon ages and lithostratigraphy studies

The Itaiacoca Belt is a sequence of metavolcanic and metasedimentary rocks that crop out east of Parana and southeast of Sao Paulo states, in southern Brazil. This geologic-geochronologic study supports division of the Itaiacoca Belt into two major lithologic sequences. The older is a carbonate platform sequence (dolomitic meta-limestones/metamarls/calc-phyllites/ carbonate phyllites) with minimum deposition ages related to the end of the Mesoproterozoic/beginning of the Neoproterozoic (1030-908 Ma:U-Pb, zircon of metabasic rocks). The younger sequence contains mainly clastics deposits (meta-arkoses/metavolcanics/metaconglomerates/metapelites) with deposition ages related to the Neoproterozoic (645-628 Ma:U-Pb,zircon of metavolcanic rocks). These ages are quite close to K-Ar ages (fine fraction) of the 628-610 Ma interval, associated with metamorphism and cooling of the Itaiacoca Belt. The contact between the dolomitic meta-limestones and meta-arkoses is marked by intense stretching and high-angle foliation, suggesting that the discontinuity between these associations resulted from shearing. It is proposed here that the term Itaiacoca Sequence, should represent the dolomitic meta-limestones, and the term Abapa Sequence represents the meta-arkoses/metavolcanics/phyllites. in a major tectonic context, these periods are related to the break-up of Rodinia Supercontinent (1030-908 Ma) and the amalgamation of the Gondwana Supercontinent (645-628 Ma). (C) 2008 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.FAPESP[06/03608-6]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP[05/58688-1

The Itajai foreland basin: a tectono-sedimentary record of the Ediacaran period, Southern Brazil

The Itajai Basin located in the southern border of the Luis Alves Microplate is considered as a peripheral foreland basin related to the Dom Feliciano Belt. It presents an excellent record of the Ediacaran period, and its upper parts display the best Brazilian example of Precambrian turbiditic deposits. The basal succession of Itajai Group is represented by sandstones and conglomerates (BaA(0) Formation) deposited in alluvial and deltaic-fan systems. The marine upper sequences correspond to the Ribeiro Carvalho (channelized and non-channelized proximal silty-argillaceous rhythmic turbidites), Ribeiro Neisse (arkosic sandstones and siltites), and Ribeiro do Bode (distal silty turbidites) formations. The ApiA(0)na Formation felsic volcanic rocks crosscut the sedimentary succession. The Cambrian Subida leucosyenogranite represents the last felsic magmatic activity to affect the Itajai Basin. The Brusque Group and the Florianpolis Batholith are proposed as source areas for the sediments of the upper sequence. For the lower continental units the source areas are the Santa Catarina, So Miguel and CamboriA(0) complexes. The lack of any oceanic crust in the Itajai Basin suggests that the marine units were deposited in a restricted, internal sea. The sedimentation started around 600 Ma and ended before 560 Ma as indicated by the emplacement of rhyolitic domes. The Itajai Basin is temporally and tectonically correlated with the Camaqu Basin in Rio Grande do Sul and the Arroyo del Soldado/Piriapolis Basin in Uruguay. It also has several tectono-sedimentary characteristics in common with the African-equivalent Nama Basin.Sao Paulo State Foundation of Research Support[FAPESP-2005/58688-1]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

I Brazilian Position Paper on Prehypertension, White Coat Hypertension and Masked Hypertension: Diagnosis and Management

Submitted by Luciana Ferreira ([email protected]) on 2019-09-17T15:33:53Z No. of bitstreams: 2 Artigo - Alexandre Alessi - 2014.pdf: 415253 bytes, checksum: dd47e772f09e9a522436e4e0548af7bf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2019-09-18T13:09:46Z (GMT) No. of bitstreams: 2 Artigo - Alexandre Alessi - 2014.pdf: 415253 bytes, checksum: dd47e772f09e9a522436e4e0548af7bf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2019-09-18T13:09:46Z (GMT). No. of bitstreams: 2 Artigo - Alexandre Alessi - 2014.pdf: 415253 bytes, checksum: dd47e772f09e9a522436e4e0548af7bf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-0