Skip to main content

Alcides Sial

Followers

5

Following

2

Co-author

1

Public Views

Stable isotope geochemist (chemostratigraphy) and igneous petrologist

less

Interests

Uploads

Papers by Alcides Sial

An isotopic insight of the Sergipano Belt Stratigraphy: Radiogenic and Carbon Isotopes

INTRODUCTION The aim of this work is to constrain the depositional time interval of some stratigr... more INTRODUCTION The aim of this work is to constrain the depositional time interval of some stratigraphic units that belong to the Sergipano fold belt (SFB), northeastern Brazil. Based on a review of the existing radiogenic and stable isotope data, as well as on field stratigraphic considerations, a new startigraphic position for the Macururé (MA) and Araticum (AT) groups is proposed as well as their relationship with other stratigraphic units. The SFB belongs to the Borborema Geotectonic Province and is located in the northern margin of the São Francisco Craton (SFC) (Fig. 1). A generalized stratigraphic division of this belt was proposed by Humphrey & Allard (1962, 1969), in which they identified that the Miaba (MI) and Vaza Barris (VB) groups are located in the SFB itself and that the Estância (ES) Group is located overlying the (SFC). North of this area, the same authors also identified biotite-garnet schists surrounding some granitic stocks, and considered them as hornfelses. On t...

Mantle Rock Exhumation at Saint Peter and Saint Paul Islets, Equatorial Atlantic Ocean, and its Implication to Possible Generation of Abiogenic Hydrocarbons by Serpentinization

Anuario do Instituto de Geociencias

Este trabalho apresenta a exumação das rochas mantélicas no Arquipélago de São Pedro e São Paulo,... more Este trabalho apresenta a exumação das rochas mantélicas no Arquipélago de São Pedro e São Paulo, Oceano Atlântico Equatorial, e sua implicação na possível geração de hidrocarbonetos abiogenéticos por serpentinização. Na zona de falhas transformantes de São Paulo, observam-se duas condições tectônicas contrastadas para exumação do manto: Distensão no centro de espalhamento amagmático e compressão ao longo da cadeia de transpressão. No fundo do oceano, as rochas ultramáficas do manto exumado reagem quimicamente com a água do mar gerando energia térmica e hidrocarbonetos abiogenéticos, o fenômeno denominado serpentinização. O espalhamento amagmático com a formação de megamullion ocorre ao longo dos segmentos inter-transformantes da cadeia meso-oceânica. As rochas ultramáficas são originadas no manto superficial e possuem serpentinização avançada e deformação plástica pouco expressiva. Os porfiroblastos de olivina apresentam fraturamento rúptil. Por outro lado, a cadeia de transpressão ocorre ao longo do trecho da falha transformante em que a direção da falha e o movimento relativo das placas são oblíquos. Devido à discordância direcional, o movimento transcorrente gera o esforço de compressão perpendicular à falha. Este esforço levanta o manto profundo subjacente a partir da profundidade de deformação dúctil até a superfície da Terra. A cadeia de transpressão no Arquipélago de São Pedro e São Paulo, denominada Cadeia de Brachiosaurus, é o único exemplo confirmado exumação do manto acima do nível do mar no Oceano Atlântico. As rochas do manto têm serpentinização pouco expressiva e deformação plástica extremamente desenvolvida, apresentando textura milonítica. Os porfiroclastos e a matriz apresentam tanto o fraturamento rúptil quanto a deformação plástica. Palavras-chave: Exumação do manto; serpentinização; hidrocarboneto abiogenético; Zona de falhas transformantes de São Paulo; cadeia de transpressão

Mercury as a proxy for volcanic activity during extreme environmental turnover: The Cretaceous–Paleogene transition

Palaeogeography, Palaeoclimatology, Palaeoecology, 2013

The usually low geological background concentrations of Hg makes this trace element suitable for ... more The usually low geological background concentrations of Hg makes this trace element suitable for identifying accumulation pulses in sediments that can be tentatively related to weathering processes and thus to climatic changes. Intense volcanism has witnessed the Cretaceous-Paleogene transition (KTB) and was, perhaps, responsible for dramatic climatic changes and decrease in biodiversity and mass extinction. We have used Hg concentrations as a proxy for volcanic activity and atmospheric Hg and CO 2 buildup across the KTB at three localities. In the Salta Basin, Argentina, Hg contents display several spikes across the KTB, with a maximum value of 250 ng•g − 1. In three drill cores across the KTB in the Paraíba Basin, northeastern Brazil, Hg contents increase from the late Maastrichtian to early Danian and Hg spikes predate the KTB, perhaps, as a record of volcanic activity before (but very close to) this transition. At Stevns Klint, Denmark, Hg contents reached almost 250 ng•g −1 within a 5 cm thick-clay layer, the Fiskeler Member ('Fish Clay') that comprises the KTB. Some co-variation between Hg and Al 2 O 3 contents has been observed in all of the studied sections across the KTB, suggesting that Hg is probably adsorbed onto clays. Thermo-desorption experiments in selected samples from the Yacoraite Formation showed Hg +2 as the major species present, which is in agreement with a volcanic origin. Combined Hg and C-isotope chemostratigraphy may become a powerful tool for the eventual assessment of the role of volcanic activity during extreme climatic and biotic events, such as those during the KTB.

High-resolution stable isotope stratigraphy of the upper Cambrian and Ordovician in the Argentine Precordillera: Carbon isotope excursions and correlations

Gondwana Research, 2013

We report the occurrence of important carbon isotope excursions in early Paleozoic formations of ... more We report the occurrence of important carbon isotope excursions in early Paleozoic formations of the Eastern and Central Argentine Precordillera. The Steptoean positive isotope carbon excursion (SPICE) is known from North America, Kazakhstan, South China, Australia and South America, and the negative isotope carbon excursion (SNICE) has been described for the first time in South America. We report here the record of the SPICE and SNICE in a single section in the Eastern Precordillera. In the Central Precordillera, a minor middle Darriwilian positive carbon isotope excursion (MDICE) and a late Sandbian positive isotope carbon excursion, the GICE (~ +3‰; C. bicornis biozone) are reported from two sections. One pre-GICE positive carbonisotope excursion (Sandbian Sa1, N. gracilis biozone) in the Central Precordillera with a  13 C peak of ~ +2‰ is, perhaps, equivalent to the positive Spechts Ferry  13 C excursion of North America. A positive  13 C excursion (~ 6‰; N. persculptus biozone) recorded at the base of the late Hirnantian La Chilca Formation probably corresponds to HICE. These carbon-isotope excursions resulted from more than one factor where paleoceanographic events probably played a major role: (a) sea-level fall and vigorous fluctuations in the Steptoean (SPICE), (b) sea-level rise in the Sunwaptan (SNICE), (c) important transgression in the Sandbian (pre-GICE and GICE), and (d) sea-level fall in the late Hirnantian (HICE). In the Darriwilian and Sandbian stages, organic burial has led to a large 12 C sequestration in the deep anoxic ocean with saline bottom water, recorded by the graptoliferous black shales of the Gualcamayo and Los Azules formations in Central Precordillera, helped the building of the MDICE and GICE anomalies.  18 O values for the Upper Cambrian carbonates are likely near-primary isotope signals that point to progressive cooling from the SPICE to the SNICE, whereas for Sandbian carbonates they suggest strong temperature fluctuations. The  13 C peak of the GICE coincides with a cooler period with temperatures warming up towards the late Hirnantian to Rhuddanian.

$Research paper thumbnail of Influence of continental fraction in recent biogenic carbonate sedimentation in the oriental shelf of Northeastern Brazil$

Influence of continental fraction in recent biogenic carbonate sedimentation in the oriental shelf of Northeastern Brazil

Revista Brasileira de …, 2008

The influence of continental sediments on formation of recent marine sediments, has been mineralo... more The influence of continental sediments on formation of recent marine sediments, has been mineralogically and geochemically studied using shelf-floor whole sediments (WS). The studied area corresponds to the oriental shelf of Northeastern Brazil between the 10 to 80m isobaths, adjacent to a continental area dominated by semi-arid to humid tropical climate. 47 representative samples from the dominating facies in this shelf have been analyzed by X-ray diffraction (XRD) and chemical analisis and results allowed identification of two types of floor sediments of: (a) quartz-terrigenous dominance and (b) carbonate dominance, whose fraction present distinct mineralogical and geochemical characteristics. In the terrigenous facies, that occur from 10 to 25-55m depths, quartz, potassic feldspar and high Mg-calcite predominate, with Sr generally <2,200 ppm. In the carbonate facies, high Mg-calcite and aragonite coexist and predominate, with Sr concentrations up to 6,400 ppm and ranging >2,600 ppm. In both cases, low-Mg calcite is absent. Even when the terrigenous fraction is found in accessory amounts (< 3% WS), geochemical signatures, marked by strong intercorrelations SiO2-Al2O3-K2O-Rb, exhibit correlation coefficients with r ≥ 0.9, reflecting a continental felsic source. The statistical analyses (co-variation between Mg/Ca and SiO2), chemistry and mineralogy of the sediments indicate that textural and mineralogical nature of the substratum is the main factor controlling the biota (dominantly benthonic in this shelf) and that, in these conditions, quartzous terrigenous facies favor species that are preserved in high Mg-calcite instead of those preserved in aragonite. This tendency showed to be independent of depth of sampling between 10 and 55 m.

Lomagundi carbon isotope anomaly in Paleoproterozoic carbonates of Brazil and Uruguay

a. NEG-LABISE, Dept. of Geology, UFPE, C.P. 7852, Recife, 50670-000, Brazil; e-mail: sial@ufpe.br... more a. NEG-LABISE, Dept. of Geology, UFPE, C.P. 7852, Recife, 50670-000, Brazil; e-mail: sial@ufpe.br b. Dept. of Geology, Faculty of Sciences, Iguá 4225, 11400 Montevideo, Uruguay; e-mail: gaucher@chasque.apc.org cFaculty of Agronomy, Garzón 780, Montevideo, Uruguay; e-mail: rojobona@adinet.com.uy d-Instituto de Geociências, Universidade Federal do Rio Grande do Sul; e-mail: leo.hartmann@ufrgs.br e. Instituto Superior de Correlación Geológica, S. M. Tucuman, Argentina, 4000; e-mail: ajtoselli@infovia.com.ar f. Department of Geology, University of Chile, Santiago, Chile; e-mail: maparada@cec.uchile.cl g. Institute of Geosciences, UFMG, Belo Horizonte, MG, Brazil, 30430-120; e-mail: noce@dedalus.lcc.ufmg.br h. Brazilian Geol. Survey (CPRM), Rua Banco da Província 105, Porto Alegre, Brazil; e-mail: wwildner@pa.cprm.gov.br

Correlations of some Neoproterozoic carbonate-dominated successions in South America based on high-resolution chemostratigraphy

Brazilian Journal of Geology, 2016

ABSTRACT: This report reviews and incorporates new elemental and isotope chemostratigraphic data ... more ABSTRACT: This report reviews and incorporates new elemental and isotope chemostratigraphic data for correlation of Neoproterozoic carbonate-dominated successions in South America (Argentina, Bolivia, Brazil, Paraguay and Uruguay). These thick mixed carbonate/siliciclastic successions were largely deposited in epicontinental basins or accumulated on passive margins on the edges of cratons (e.g. São Francisco, Amazonia, Rio Apa Block, Pampia and Río de la Plata paleocontinents) during extensional events related to the rifting of the Rodinia Supercontinent. From the stratigraphic point of view, these successions occur as three mega-sequences: glaciogenic, marine carbonate platform (above glaciomarine diamictites or rift successions), and dominantly continental to transitional siliciclastics. In the orogenic belts surrounding cratons, carbonate-dominated successions with important volcanoclastic/siliciclastic contribution have been, in most cases, strongly deformed. The precise ages of...

C and Sr isotopic evolution of carbonate sequences in NW Argentina: Implications for a probable Precambrian-Cambrian transition

Upper Precambrian-Lower Cambrian sequences in the Tucuman, Salta and Jujuy provinces, NW Argentin... more Upper Precambrian-Lower Cambrian sequences in the Tucuman, Salta and Jujuy provinces, NW Argentina, comprise sandstone, slate, conglomerate and black limestone (Las Tienditas/Volcan Fms.) with abundant Vendian/Tommotian trace fossils in the clastic facies rocks. The Precordillera basin, San Juan province, represents a continuous carbonate sequence belonging to the Lower to Middle Cambrian La Laja Fm. The Pie-de-Palo Range, Pampean Range, characterized by carbonates intercalated with greenschist/amphibolite facies metaclastic rocks, forms a part of the Precordillera basement. The δ13C values in carbonates of the Las Tienditas Fm. show a gradual decrease from the base (+3.4 ‰PDB) to the top with a minimum of −1.6‰ observed at ∼15m from the top, the latter having a higher clay content. Carbonates in a 700m thick section within La Laja Fm. is marked by a slightly positive δ13C values at the base (marly) with a negative anomaly (−2.0‰) at ∼20 m above, followed by a small positive anomaly...

Principal component analysis (PCA) and mineral associations of litoraneous facies of continental shelf carbonates from northeastern Brazil

The distribution of mineral phases according to the provenance of carbonate and terrigenous facie... more The distribution of mineral phases according to the provenance of carbonate and terrigenous facies of carbonate sediments from a large area of the continental shelf of northeast Brazil was investigated using a major element multivariate analysis approach. Heavy minerals such as ilmenite are restricted to the litoraneous facies of the continental shelf of the states of Paraiba and Pernambuco, and clay minerals are found in distal facies of the continental shelf of the State of Ceara. In the carbonate fraction, composed essentially by Mg-calcite and aragonite, there is co-variation between CaO/MgO and bathimetry in part of the studied continental shelf from depths between 15 and 20 m, apparently due to influence of the seawater temperature, degree of oxygenation and luminosity. The terrigenous facies are mainly composed of quartz, clay minerals, K-feldspars and micro-micaceous minerals, having Fe and Ti oxide and hydroxide minerals as major accessory phases. Major element behavior att...

C-isotope variability in the Delhi Supergroup, NW India: Implications for Meso-Neoproterozoic transition

Soils are dynamic chemical systems that actively record climatic variations through the precipita... more Soils are dynamic chemical systems that actively record climatic variations through the precipitation of secondary minerals in the soil, including opaline silica, carbonate and clays. The maximum age of a soil reflects the stabilization of an erosional surface, providing additional information about past climates and their effects. In situ dating of secondary minerals provides a means of determining the maximum age of a particular deposit (shoreline, terrace or alluvial fan) and can also provide long-term records that reflect local paleoclimate variations and provide genetic information pertaining to the formation of younger surfaces. In situ dating approaches are necessary for developing long-term climate records from soils using pedogenic carbonate and silica because of the slow growth rates (ca. u/kyr), the possibility of episodic growth, and the complex mixtures of minerals and detrital contaminants that are often incorporated into pedogenic deposits. Using the ion microprobe (S...

δ13C stratigraphy of the Birmania Basin, Rajasthan, India: implications for the Vendian–Cambrian transition

The Birmania Basin is an oval-shaped, isolated remnant of the Marwar Basin (Neoproterozoic–Early ... more The Birmania Basin is an oval-shaped, isolated remnant of the Marwar Basin (Neoproterozoic–Early Palaeozoic), located in the heart of the Thar Desert of western Rajasthan, India. The Birmania Basin comprises a 900 metre-thick sedimentary sequence of siliciclastic, carbonate and phosphorite facies. δ13C and δ18O-values are presented in this paper, based on samples of phosphorite and carbonate collected at close intervals along two sample lines near Birmania and Kohra in the Birmania Basin, Rajasthan, India. The carbonates of the Birmania Basin sampled have suffered neither deep burial nor alteration and may provide pristine samples of the C-cycle at the time of their deposition. These values can be useful in inter-regional correlation, particularly for unfossiliferous successions. The carbon isotopic pattern observed in the Birmania succession appears to be similar to that observed in well-established Precambrian–Cambrian boundary sections globally. A worldwide phase of phosphogenesi...

Beachrocks of Jaguaribe Beach, Itamaracá Island, Ne Brazil: Petrographic and Geochemistry Evidences

Contemporaneous beachrocks that runs parallel to the coast forming long, discontinuous and narrow... more Contemporaneous beachrocks that runs parallel to the coast forming long, discontinuous and narrow lines. Geochemical analyses were executed on carbonate beachrocks and water samples on Itamaracá Island, Pernambuco State, Brazil. Framework detrital composition is siliciclastic and cemented by calcite and/or aragonite. Three types and stages of cementation have been identified. The first correspond to micritic envelope; the second, acicular fringe; and the third, criptocrystalline cement filling the pores. The δC values and diagenesis features suggest which the cementation occurs in meteoric-vadose and/or marine-phreatic by loss of CO2 in evaporation of the interstitial water. The interaction of the carbonated fluid in subsuperficies permitted the discontinuous beachrock formation. The elevation of the mean sea level deposits new sediments, which cemented, complete preexists base of the beachrock, or creates a different, justifying the different dimensions this rocks on the littoral.

C-and Sr-isotope systematics applied to Neoproterozoic marbles of the Seridó belt, northeastern Brazil

The Serido fold belt, situated in the northeastern part of the Borborema Province in northeastern... more The Serido fold belt, situated in the northeastern part of the Borborema Province in northeastern Brazil, has been the target of several studies in the last two decades. Previous field and structural studies suggested a Paleoproterozoic age, but recent isotopic data raised the possibility that the original sediments were deposited and metamorphosed during the Neoproterozoic. Detailed C and Sr isotope studies in marbles of the Serido Group clarify this issue. In the Jucurutu Formation, at the base of the Serido Group, δ 13 C fluctuations indicate three stratigraphic levels of carbonate sedimentation. Basal marbles, consisting of calcite, amphibole, phlogopite, quartz and opaques, display δ 13 C between +8.3 and +10.8‰V-PDB. Values of δ 13 Cb+8.3‰V-PDB are observed in marble samples close to the contact with metapelites, or when silicate minerals are more abundant. Intermediate marbles are composed of calcite, tremolite, phlogopite, quartz, opaques, and wollastonite and exhibit δ 13 C...

Granitos Com Epidoto Magmático e Clinopiroxênio: Plútons Tamboril e Olho D’Água, Terreno Cachoeirinha−salgueiro, Nordeste Do Brasil

Granitos Ediacaranos calci-alcalinos, calci-alcalinos de alto potassio, shoshoniticos, peralcalin... more Granitos Ediacaranos calci-alcalinos, calci-alcalinos de alto potassio, shoshoniticos, peralcalinos e trondhjemiticos intrudiram o Terreno Cachoeirinha-Salgueiro (CST) no Dominio da Zona Transversal, Nordeste do Brasil. Os plutons Tamboril e Olho d’Agua tem assembleias mineralogicas semelhantes, mas texturas distintas. O pluton Olho d’Agua e composto de clinopiroxenio-biotita tonalito de granulacao media, equigranular, com anfibolio e epidoto magmatico, enquanto que o pluton Tamboril consiste de biotita granodiorito medio a grosso, porfiritico, com clinopiroxenio e megacristais de plagioclasio. Nos plutons Tamboril e Olho d’Agua, clinopiroxenio e substancialmente menos abundante quando ha a presenca de epidoto, ou seja, o aumento de clinopiroxenio modal e diretamente proporcional a diminuicao do epidoto modal, assim como ocorre no pluton Pedra Branca. Os xenolitos ricos em anfibolios sao considerados fragmentos que se destacaram de uma fonte profunda e podem representar restitos da ...

Nd-Sr isotopic composition of microgranular enclaves of the Brejinho Batholith, Alto Pajeú Terrane, Borborema Province, NE Brazil

INTRODUCTION The microgranular enclaves of intermediate to mafic composition are common in granit... more INTRODUCTION The microgranular enclaves of intermediate to mafic composition are common in granitoid rocks, especially in calc-alkaline suites, being considered, in general, as products of incomplete mixing between coeval magmas of acid and mafic composition from different origins. They can also be interpreted as: a refractory residue of mafic rocks remnants of an igneous protolith which was partially melted to yield the host granitoid magma (restite model), or b -together with the granitoids, originated by differentiation of a parental mafic magma constituting the “autoliths”. In this case, these last two interpretations are less likely, in agreement with isotopic, petrographic, chemical and field constraints, so that the enclaves and the granitoids hosts are considered as representatives of two coexisting magmas, but with different composition and origin (Torres, 2001). Among other investigation lines, the isotopic composition of mafic enclaves and granitoid hosts constitute one o...

Isótopos De Carbono e Oxigênio Dos Mármores Associados Com O Depósito Fósforo Uranífero De Itataia, Ceará

The phosphorous-uranium deposit of Itataia, Ceara State, NE Brazil, is characterized by colophani... more The phosphorous-uranium deposit of Itataia, Ceara State, NE Brazil, is characterized by colophanites that occur as massive and irregular bodies, and as veins, associated to marbles and calc-silicate lenses that are enclosed in Meso to neoproterozoic pelitic and psamitic metasediments rocks metamorphosed under high amphibolite-facies. Centimetric to metric muscovite- and tourmaline-bearing pegmatitic bodies are common and crosscut both the metapelites and their anatetic products. Plagioclase-rich phyllosilicate-poor pegmatites cut different marble levels, some of which are mineralized in colophane. The marble beds, which are the main ore host-rock, show a heterogeneous structural pattern as a result of complex folding and thrusting. C and O isotope analyses in carbonates from one of the sections that crosscut partially mineralized metacarbonatic rocks show d13CPDB values ranging from +2,0 to -5,0‰ and d18OSMOW values from +16,3 to +24,2‰. Changes in the original isotopic ratios are m...

First geochronological constraint for the Palaeoproterozoic Lomagundi-Jatuli δ13C anomaly in the Tandilia Belt basement (Argentina), Río de la Plata Craton

Geochronological data of Palaeoproterozoic carbonates with δ13C values between +5‰ and +16‰ sugge... more Geochronological data of Palaeoproterozoic carbonates with δ13C values between +5‰ and +16‰ suggest that the positive carbon isotope excursion of the global Lomagundi-Jatuli event (LJE) occurred mostly between 2220 and 2060 Ma. In the southern portion of the Rio de la Plata Craton, the LJE was recorded in calcite-diopside marble of the Tandilia Belt basement. The marble was found at the San Miguel area as part of a metamorphic rock assemblage, mainly composed of gneisses and migmatites, formed during the Transamazonian Orogeny. The latter represents the maximum magmatic and metamorphic activity in the Tandilia Belt basement. The marble, derived from a calcareous-siliciclastic sedimentary marine sequence, was intruded by leucogranites that provoked the San Miguel skarn formation. First U-Pb LA-ICP-MS age of 2206 ± 14 Ma, obtained from titanites of the skarn, also placed the metasomatic processes into the Transamazonian Orogeny. In addition, this age corresponds to the minimum age for...

Could Eremotherium laurillardi (Lund, 1842) (Megatheriidae, Xenarthra) be an Omnivore Species?

Anuário do Instituto de Geociências

We present carbon (δ13Ccollagen = -10.1 ‰) and nitrogen (δ15N = 6.8 ‰) isotopic data for E. lauri... more We present carbon (δ13Ccollagen = -10.1 ‰) and nitrogen (δ15N = 6.8 ‰) isotopic data for E. laurillardi from Brejo da Madre de Deus, Pernambuco (Brazil) and discuss the possibility of an omnivore diet for it. Our data, although ponctual, reinforce the hypothesis that E. laurillardi was a herbivore species.

30my Building a Granitic Batholith: The Santana do Ipanema Batholith, Northeastern Brazil

Goldschmidt Abstracts

Rapid magma ascent and formation of the Águas Belas-Canindé granitic batholith, NE Brazil: evidence of epidote dissolution and thermobarometry

Brazilian Journal of Geology

Mineral chemistry and intensive parameter estimates for the Major Isidoro (626 Ma) and Monteirópo... more Mineral chemistry and intensive parameter estimates for the Major Isidoro (626 Ma) and Monteirópolis (627 Ma) magmatic epidote-bearing granitic plutons, emplaced along the Jacaré dos Homens transpressional shear zone (JHSZ), Borborema Province, are focused in this study. These plutons consist of medium-to-coarse grained equigranular to porphyritic tonalite to granite that show abundant dioritic enclaves. These granites contain biotite (Fe# 0.44 to 0.55), Fe-edenite (Major Isidoro), hastingsite (Monteirópolis), titanite, and epidote that often show allanite core as key mafic mineral phases. Pistacite molecular content in epidote is in the interval of 27 to 31 mol%, presenting TiO 2 < 0.30%, typical for magmatic epidote. Estimated intensive parameters reveal crystallization at 6.5 ± 1 (Major Isidoro) and 4.7 ± 0.6 kbar (Monteirópolis), temperatures from ~940°C (near-liquidus) to 675 ± 35°C (near-solidus) and oxidizing conditions. Partial corrosion of epidote took place during 15.6 to 32 (Major Isidoro) and 27-49 years (Monteirópolis), corresponding to rather high magma ascension rates of 365 to 750 and 395 to 635 m.years-1 , respectively. The JHSZ likely favored upward magma transport at the Sergipano and Pernambuco-Alagoas domains boundary, during the onset of the Brasiliano orogeny (650-620 Ma).