Brazilian Journal of Geology最新文献_第10页

Whole-rock trace element analyses via LA-ICP-MS in glasses produced by sodium borate flux fusion 硼酸钠熔合玻璃中全岩微量元素的LA-ICP-MS分析

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2021-01-01 DOI: 10.1590/2317-4889202120200057

F. Leitzke, A. Wegner, C. Porcher, N. Vieira, J. Berndt, S. Klemme, R. Conceição

{"title":"Whole-rock trace element analyses via LA-ICP-MS in glasses produced by sodium borate flux fusion","authors":"F. Leitzke, A. Wegner, C. Porcher, N. Vieira, J. Berndt, S. Klemme, R. Conceição","doi":"10.1590/2317-4889202120200057","DOIUrl":"https://doi.org/10.1590/2317-4889202120200057","url":null,"abstract":"Trace elements provide crucial information about the origin and evolution of the Earth. One common issue regarding their analyses is the reduced analyte recovery during hot plate acid digestion for some geological samples. To overcome this, alkali fluxes (e.g., Lithium borate) have been used to produce an homogeneous synthetic glass that can be used then for both X-ray fluorescence (XRF) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). In this sense, we developed a method for LA-ICP-MS whole rock trace element analyses in glasses prepared by mixing high-purity sodium tetraborate and rock powders at high-temperature. We selected six international reference materials including peridotite ( JP-1), basalt (BRP-1), kimberlite (SARM-39), pyroxenite (NIM-P), diorite (DR-N) and andesite ( JA-1). Glasses were produced in a fully automatic fusion machine with step heating. Run products analyses were carried out on a Thermo® Element2 SF-ICP-MS coupled to a New Wave Research® Nd:YAG (213 nm) laser ablation system and on a Thermo® Element XR ICP-MS coupled to an Analyte G2 (193 nm) LA system. Results show that glasses are homogeneous and there is good agreement (generally > 90%) between our data and literature values for most trace elements, including large ion lithophile elements (LILE), high-field strength elements (HFSE) and rare-earth elements (REE).","PeriodicalId":9221,"journal":{"name":"Brazilian Journal of Geology","volume":"38 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80319289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Geochemical evolution of soils developed from pyroclastic rocks of Trindade Island, South Atlantic 南大西洋特林达德岛火山碎屑岩发育土壤的地球化学演化

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2021-01-01 DOI: 10.1590/2317-4889202120200073

A. Mateus, A. Varajão, F. Oliveira, S. Petit, C. Schaefer

{"title":"Geochemical evolution of soils developed from pyroclastic rocks of Trindade Island, South Atlantic","authors":"A. Mateus, A. Varajão, F. Oliveira, S. Petit, C. Schaefer","doi":"10.1590/2317-4889202120200073","DOIUrl":"https://doi.org/10.1590/2317-4889202120200073","url":null,"abstract":"The geochemical behavior of the major, minor, trace and rare earths elements (REEs) in soil profiles from ultramafic volcanoclastic rocks of the Vulcão do Paredão and Morro Vermelho Formation from Trindade Island (TI) was analyzed in this study. Losses and gains of chemical elements were calculated through the mass balance for two profiles along the slope: one located at higher altitude (460 m) and the other at lower altitude (258 m). In all profiles, Al, Fe and Ti accumulate due to their low mobility, whereas Ca, Na, K and Mg are the most intensely leached. Soils located at lower altitude show higher K and Mg values in the surface due to the contribution of saline sprays. Leaching of the REEs from higher to the lower slope led to the enrichment of these elements, especially the light REEs, in the soil at the lowest altitude (258 m). The high altitude profile showed Ce positive anomaly due to longer exposure to weathering. The geochemical balance shows a relative enrichment of Ti, Mn, Fe, Co, Cr, Ni, V, Zr, S related to the loss of mobile elements during the soil formation process, despite the youthful nature of these volcanic rocks.","PeriodicalId":9221,"journal":{"name":"Brazilian Journal of Geology","volume":"139 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82618981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Ediacaran/Early Cambrian Serra da Saudade Formation, Bambuí Group: the sedimentary record of a foreland basin in Southeastern Brazil 埃迪卡拉纪/早寒武世Serra da Saudade组Bambuí群:巴西东南部前陆盆地的沉积记录

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2021-01-01 DOI: 10.1590/2317-4889202120210029

D. S. Moreira, A. Uhlein, G. Uhlein, A. Sial, Edinei Koester

引用次数: 2

Identification and analysis of bottom simulating reflectors in the Foz do Amazonas Basin, Northern Brazil 巴西北部Foz do Amazonas盆地海底模拟反射体识别与分析

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2021-01-01 DOI: 10.1590/2317-4889202120200075

L. Aguiar, A. Freire, C. Silva, W. Lupinacci

引用次数: 1

Melt-melt immiscibility and implications for the origin of Madeira albite-rich granite, Pitinga mine, Amazonas, Brazil: A melt inclusion study 巴西亚马逊州Pitinga矿马德拉富钠长石花岗岩的熔体-熔体不混溶性及其成因:熔体包裹体研究

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2021-01-01 DOI: 10.1590/2317-4889202120210011

Régis Munhoz Krás Borges, L. E. D. Amorim, F. Rios, Gabrielle Cristine Silva dos Santos, M. E. Freitas, Tatiana Aparecida Fernandes de Lima, Armindo Santos, T. Pedrosa

引用次数: 1

The Santa Vitória Alloformation: an update on a Pleistocene fossil-rich unit in Southern Brazil Santa Vitória异形:巴西南部一个富含化石的更新世单元的更新

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2021-01-01 DOI: 10.1590/2317-4889202120200065

R. P. Lopes, S. Dillenburg, J. Savian, J. Pereira

{"title":"The Santa Vitória Alloformation: an update on a Pleistocene fossil-rich unit in Southern Brazil","authors":"R. P. Lopes, S. Dillenburg, J. Savian, J. Pereira","doi":"10.1590/2317-4889202120200065","DOIUrl":"https://doi.org/10.1590/2317-4889202120200065","url":null,"abstract":"The Santa Vitória Formation is a lithostratigraphic unit known for its fossil assemblage of Pleistocene mammals, established in 1973 from sediments exposed along the banks of Chuí Creek, in the southern coastal plain of the state of Rio Grande do Sul (CPRS), Brazil. The original description was presented in a Masters’ dissertation and never formally described in a peer-reviewed publication. Moreover, surveys and fossil collecting efforts developed in the last decade have led to a better understanding of its origin and nature. An updated description of this unit is presented here, which outcrops in areas occupied by barrier-lagoon depositional systems originated by eustatic oscillations. The formation encompasses Middle-Upper Pleistocene fluvial and eolian depositional systems and paleosols formed chiefly of fine to medium quartz sand, with subordinate clay, concentrations of iron and manganese oxides, and caliche nodules of pedogenic origin. It conformably overlies upper shoreface-foreshore marine deposits, and is overlain by loess deposited during the last glacial period. Here is proposed to re-define it as Santa Vitória Alloformation, considering that the use of an allostratigraphic framework to characterize this unit has the practical purpose of group-ing depositional systems genetically unrelated to the barrier-lagoon systems.","PeriodicalId":9221,"journal":{"name":"Brazilian Journal of Geology","volume":"17 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74732020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Transition from contractional to transpressive tectonics: evidence from the Feira Nova Region, Rio Capibaribe Domain, Borborema Province, NE Brazil 从收缩构造到压迫构造的转变:来自巴西东北部borborrema省Rio Capibaribe地区Feira Nova地区的证据

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2021-01-01 DOI: 10.1590/2317-4889202120200049

V. L. Silva, S. Neves

{"title":"Transition from contractional to transpressive tectonics: evidence from the Feira Nova Region, Rio Capibaribe Domain, Borborema Province, NE Brazil","authors":"V. L. Silva, S. Neves","doi":"10.1590/2317-4889202120200049","DOIUrl":"https://doi.org/10.1590/2317-4889202120200049","url":null,"abstract":"Differences in tectonic style and kinematics in orogenic belts can result from either multiphase or progressive deformation. In eastern Borborema Province, a regional shallow dipping foliation is multiply folded and crosscut by transcurrent shear zones. Here, we investigate if these fabrics resulted from diachronous deformational events or from a single-phase progressive deformation. The study area, the Feira Nova region, mostly comprises metasedimentary rocks from the Surubim Complex, and is bounded by the NE-trending sinistral Gloria do Goitá (GGSZ) and the sinistral contractional Paudalho (PSZ) shear zones, which separate it from Paleoproterozoic basement rocks. Structures can be grouped into a contractional and a transpressional stage, both related to the Brasiliano Orogeny. The contraction-related structures are represented by a gently dipping foliation (S2) related to a top-to-the-NW tectonic transport. The contact between the metasedimentary and basement rocks is parallel to S2, indicating the fabrics in both lithotypes are of Brasiliano age, with strain localization having produced the PSZ. NW-verging macroscopic folds are consistent with this regime. The following transpression generated steep mylonitic foliation (S3) mainly along the GGSZ, and caused refolding. The data here presented are consistent with a progressive deformation history comprising a gradual transition from contraction to transpression.","PeriodicalId":9221,"journal":{"name":"Brazilian Journal of Geology","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84854273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

The 1.88 Ga Uatumã Magmatism in the Serra dos Magalhães region: petrology and implications to the extension of the south-eastern edge of the Amazonian Craton Serra dos magalh<e:1>地区1.88 Ga Uatumã岩浆活动:岩石学及其对亚马逊河克拉通东南边缘伸展的意义

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2021-01-01 DOI: 10.1590/2317-4889202120200046

I. Lima, Ronaldo Pierosan, Márcia Aparecida de Sant'Ana Barros, R. Rubert, C. Sommer, Diogo Isamu de Almeida Okuno

{"title":"The 1.88 Ga Uatumã Magmatism in the Serra dos Magalhães region: petrology and implications to the extension of the south-eastern edge of the Amazonian Craton","authors":"I. Lima, Ronaldo Pierosan, Márcia Aparecida de Sant'Ana Barros, R. Rubert, C. Sommer, Diogo Isamu de Almeida Okuno","doi":"10.1590/2317-4889202120200046","DOIUrl":"https://doi.org/10.1590/2317-4889202120200046","url":null,"abstract":"The Amazonian Craton (AC) is a Pre-Cambrian tectonic segment that extends over 4.3 × 10 5 km 2 at the northern portion of the South American Platform. Phanerozoic sedimentary basins cover most of the edges of the AC and sparse occurrences of Precambrian rocks may aid the definition of its extension. One of these occurrences is the volcano-plutonic rocks that outcrop in the Serra dos Magalhães region, which relates to the Uatumã Magmatism, an expressive Orosirian magmatic event that constitutes a Siliceous Large Igneous Province. Effusive rhyodacites and rhyolites comprise the volcanic unit and the plutonic counterpart consists of epizonal monzogranites. Whole-rock geochemistry indicates an A2-type granite affinity to all magmatic rocks. Contrasting signatures suggest a magmatic evolution from a single stratified magma chamber. U-Pb zircon crystallization ages are 1870 ± 11 Ma for the rhyodacites, 1879 ± 5 Ma for the monzogranites, and a slightly younger age of 1863 ± 14 Ma for the rhyolites. Interpretation of satellite and geophysical images allows the recognition of regional lineaments in the Parecis and Bananal basins that suggest the extension of the AC up to the Tucurui Fault in the eastern portion (Bananal Basin) and up to the Brasnorte High in the southern part (Parecis Basin).","PeriodicalId":9221,"journal":{"name":"Brazilian Journal of Geology","volume":"20 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88206082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Morphometric and structural diagnosis of fault reactivation in the Cenozoic: a case study of the Blumenau-Soledade Lineament in southern Brazil 新生代断层恢复活动的形态计量学和构造诊断——以巴西南部Blumenau-Soledade剖面为例

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2021-01-01 DOI: 10.1590/2317-4889202120200080

Eduardo Salamuni, C. Silva, Edenilson Roberto do Nascimento, J. Santos, W. Peyerl, V. Gimenez

引用次数: 2

The origin of supergene nickeliferous chlorite in the Santa Fé Ni-Laterite Deposit, GO, Brazil 巴西GO Santa f<s:1>镍红土矿床表生含镍绿泥石的成因

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2021-01-01 DOI: 10.1590/2317-4889202120200119

Matheus Lamas Machado, C. Porto, L. Santoro, F. Putzolu, R. Neumann, A. Bastos Neto, H. Polivanov, Richard Herrington

引用次数: 2