Brazilian Journal of Geology最新文献_第5页

Differences in the occurrence of debris flows in tropical and temperate environments: field observations and geomorphologic characteristics in Serra do Mar (Brazil) and British Columbia (Canada) 在热带和温带环境中泥石流发生的差异:在Mar山(巴西)和不列颠哥伦比亚省(加拿大)的实地观测和地貌特征

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2022-01-01 DOI: 10.1590/2317-4889202220210064

V. C. Dias, A. Mitchell, B. Vieira, S. McDougall

{"title":"Differences in the occurrence of debris flows in tropical and temperate environments: field observations and geomorphologic characteristics in Serra do Mar (Brazil) and British Columbia (Canada)","authors":"V. C. Dias, A. Mitchell, B. Vieira, S. McDougall","doi":"10.1590/2317-4889202220210064","DOIUrl":"https://doi.org/10.1590/2317-4889202220210064","url":null,"abstract":"Debris flows are among the most destructive types of mass movements throughout the world and are not restricted to certain climate zones or geological environments. In opposite corners of the American continent, Canada and Brazil have experienced several historic debris flows. As part of a one-year international exchange program, the lead author compared morphological evidence related to debris flows and the morphometry of watersheds at sites in Canada and Brazil, with the ultimate goal of improving the understanding of debris flows in Brazil. Field surveys carried out in both areas in 2019 and 2020 permitted observation of the debris-flow signatures, as well as the physical aspects of the surrounding areas and morphometric mapping of watersheds. Both areas exhibit similar typical features of debris flows, and the morphometric results indicate differences that may influence the recurrence of events at the sites in Canada as compared to Brazil due to their higher values for the parameters area > 25° (A25), relief ratio (Rr), and Melton ratio (Mr) at the Canadian sites; however, this dataset is limited. Compared to results in the literature from around the world, values of morphometric parameters at Brazilian sites are within the ranges observed in other tropical climates.","PeriodicalId":9221,"journal":{"name":"Brazilian Journal of Geology","volume":"34 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91234040","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: 0

The Cauê Aquifer on the eastern limb of the Moeda Syncline: characterization, impacts, and flow in the western Iron Quadrangle (Quadrilátero Ferrífero), MG, Brazil Moeda向斜东翼Cauê含水层:特征、影响和西部铁四边形(Quadrilátero Ferrífero)，巴西MG

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2022-01-01 DOI: 10.1590/2317-4889202220220005

Celina Cenni de Castro Magalhães, M. Melo, N. Guiguer, R. S. Paula

引用次数: 1

Validation of the use of portable equipment for magnetic characterization of soils, State of Paraná, Brazil 使用便携式设备进行土壤磁性表征的验证，巴西帕拉纳<e:1>州

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2022-01-01 DOI: 10.1590/2317-4889202220220011

H. S. Costa, O. Licht, F. J. Ferreira, E. M. G. Vasconcellos, Antonio Carlos Saraiva da Costa

引用次数: 0

U-Pb zircon age of Ediacaran Umarizal Granite Suite and emplacement mechanism with high-T hornfels generation in Jucurutu Formation, Borborema Province, NE, Brazil 巴西东北部borborrema省juurutu组埃迪卡拉系Umarizal花岗岩组U-Pb锆石年龄及高t角砾岩成因机制

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2022-01-01 DOI: 10.1590/2317-4889202220200129

Samir do Nascimento Valcácio, Z. Souza, E. Oliveira

{"title":"U-Pb zircon age of Ediacaran Umarizal Granite Suite and emplacement mechanism with high-T hornfels generation in Jucurutu Formation, Borborema Province, NE, Brazil","authors":"Samir do Nascimento Valcácio, Z. Souza, E. Oliveira","doi":"10.1590/2317-4889202220200129","DOIUrl":"https://doi.org/10.1590/2317-4889202220200129","url":null,"abstract":"The Borborema Province, NE Brazil, is marked by several Ediacaran granitic plutons that generated high-temperature metamorphic aureoles in the country rock. However, information about magma emplacement, age of plutonism, and metamorphic conditions are necessary to understand this scenario. To this end, we present field, petrographic, and zircon U-Pb geochronological data for migmatized hornfels and intrusive Umarizal and Tourão-Caraúbas plutons. The field features allowed the construction of a structural evolution model starting with high-temperature sinistral strike-slip shear zones followed by dextral strike-slip movement associated with the magmatic emplacement. Mineral paragenesis of andalusite/sillimanite, garnet, scapolite, and phlogopite in country rocks within the metamorphic aureole indicate temperatures of at least 700-800°C and pressures lower than 4.5 kbar corresponding to the pyroxene hornfels facies. Zircon U-Pb ages of 563.7 ± 6.2 for the Umarizal granite, 589 ± 4.4 Ma for the Tourão-Caraúbas granite, and 580.5 ± 4 Ma for the neosome from contact aureole were obtained. The results show that magma emplacement and HT/LP (high-T/low-P) contact metamorphism were synchronous with a transtensional event. These features suggest a late- to post-tectonic context, following the collapse of the Brasiliano/Pan-African orogenetic chain, that favored Late Ediacaran plutonism and synchronous HT/LP metamorphism.","PeriodicalId":9221,"journal":{"name":"Brazilian Journal of Geology","volume":"91 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85654429","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

Interactions between tectonics, bedrock inheritance and geomorphic responses of rivers in a post-rifting upland (Ponta Grossa Arch region, Brazil) 裂谷后高地构造、基岩继承与河流地貌响应的相互作用(巴西蓬塔格罗萨拱地区)

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2022-01-01 DOI: 10.1590/2317-4889202220210002

M. Santos, F. Ladeira, A. Batezelli, J. O. R. Nunes, Eduardo Salamuni, C. Silva, E. Molina, I. C. Moraes

引用次数: 4

Resende lamprophyres: new petrological and structural interpretations for a regional Upper Cretaceous alkaline mafic dyke swarm 热仙德煌斑岩:区域性上白垩统碱性基性岩脉群的岩石学和构造新解释

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2022-01-01 DOI: 10.1590/2317-4889202120210043

Bruno Neves Macedo, Rodrigo Peternel, A. Santos, Marcela Perroti Simas

引用次数: 2

Late Paleozoic glacial to postglacial stratigraphic evolution of the Rio do Sul depocenter, Itararé and Guatá groups, Pennsylvanian-Cisuralian, southern Brazil 巴西南部宾夕法尼亚-西苏拉系itarar<s:1>和guat<e:1>群南Rio do沉积中心晚古生代至冰期后地层演化

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2022-01-01 DOI: 10.1590/2317-4889202220220027

D. Schemiko, F. Vesely, Mérolyn Camila Naves de Lima Rodrigues

引用次数: 1

Inventory of natural processes with nautical charts, real-time kinematic global navigation satellite systems (RTK-GNSS), and unmanned aerial vehicle (UAV), Trindade Island, Brazil 带有海图的自然过程清单，实时运动学全球导航卫星系统(RTK-GNSS)和无人机(UAV)， Trindade岛，巴西

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2022-01-01 DOI: 10.1590/2317-4889202220220007

Fernanda Avelar Santos, M. C. Souza, Lázaro Valentin Zuquette, R. J. Angulo, M. Rosa, Adriana Ahrendt Talamini, C. A. Figueiredo

{"title":"Inventory of natural processes with nautical charts, real-time kinematic global navigation satellite systems (RTK-GNSS), and unmanned aerial vehicle (UAV), Trindade Island, Brazil","authors":"Fernanda Avelar Santos, M. C. Souza, Lázaro Valentin Zuquette, R. J. Angulo, M. Rosa, Adriana Ahrendt Talamini, C. A. Figueiredo","doi":"10.1590/2317-4889202220220007","DOIUrl":"https://doi.org/10.1590/2317-4889202220220007","url":null,"abstract":"The volcanic Trindade Island is a remote Brazilian offshore territory in the South Atlantic, located ca. 1.140 kilometers east of the southeast coast of Brazil. The island’s permanent exposure to geological hazards requires assessment. However, the lack of erosion and landslides temporal data impedes predictive geohazard analyses. Therefore, we compiled pre-existing data from nautical charts and surveyed the surface terrain on Trindade Island to generate Digital Terrain Models (DTMs) and comparative accuracy analyses. The DTM based on pre-existing data shows the lowest accuracy (root mean square error – RMSE: 12.3 m) yet is adequate for regional studies. In contrast, the DTM developed from real-time kinematic global navigation satellite systems (RTK-GNSS) has the highest vertical accuracy (RMSE: 0.48 m), but spatial variability of ground elements was underestimated and limited to meter-sized (and larger) elements. The DTM obtained using the unmanned aerial vehicle (UAV) with ground control points (GCP), on the other hand, presented lower accuracy (RMSE: 2.37 m) than the RTK-GNSS model but still allowed observation of centimetric (and larger) ground features. For geohazard assessment on Trindade Island, models that allow fine-scale studies are needed. A UAV with GCP provides such standards and proved to be the most viable option in remote and complex sites as well. Hence, this study, the first to allow multi-temporal analysis of geohazard assessment on Trindade Island, offers a viable solution for similar analyses in other remote locations.","PeriodicalId":9221,"journal":{"name":"Brazilian Journal of Geology","volume":"65 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80996740","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: 0

New occurrences of Chonetoidea (Brachiopoda) in the Devonian of Bolivia, Peru and Antarctica 玻利维亚、秘鲁和南极洲泥盆纪腕足科的新发现

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2022-01-01 DOI: 10.1590/2317-4889202120210080

R. Videira-Santos, S. Scheffler, A. Fernandes

引用次数: 0

Methodological approach and general guidelines to geochemical mapping and background-baseline analysis for environmental assessment: a case study in the Carajás Mineral Province, Brazil 用于环境评价的地球化学制图和背景基线分析的方法方法和一般准则:巴西Carajás矿产省的个案研究

IF 1.4 4区地球科学

Brazilian Journal of Geology Pub Date : 2022-01-01 DOI: 10.1590/2317-4889202220220018

P. Souza-Filho, P. Sahoo, M. S. Silva, R. Dall’Agnol, Carlos Augusto Medeiros Filho, A. Leite, Jair da Silva Ferreira Júnior, W. N. Nascimento Junior, Géssica da Silva e Silva, G. Salomão, Fabiana Sarracini, Renato Oliveira Silva Júnior, M. Costa

引用次数: 1