8 documents found, page 1 of 1
Mercury anomaly, Deccan volcanism, and the end-Cretaceous mass extinction
Font, Eric; Adatte, Thierry; Sial, Alcides Nobrega; Lacerda, Luiz Drude de; Keller, Gerta; Punekar, JahnaviThe contribution of the Deccan Traps (west-central India) volcanism in the CretaceousPaleogene (KPg) crisis is still a matter of debate. Recent U-Pb dating of zircons interbedded within the Deccan lava flows indicate that the main eruptive phase (>1.1 × 106 km3 of basalts) initiated ~250 k.y. before and ended ~500 k.y. after the KPg boundary. However, the global geochemical effects of Deccan volcanism in the ma...
C-, Sr-isotope and Hg chemostratigraphy of Neoproterozoic cap carbonates of the...
Sial, Alcides Nobrega; Gaucher, Claudio; Silva Filho, Marinho Alves da; Pimentel, Marcio M.; Lacerda, Luiz Drude de; Silva Filho, Emmanoel V.Two cap carbonates overlying glaciogenic diamictites crop out extensively in the eastern Vaza Barris Domain of the Sergipano Belt, northeastern Brazil. They are represented by carbonates of the Jacoca Formation, resting on top of diamictite of the Ribeiropolis Formation, and by the Olhos D’Agua Forma- tion (carbonates, organic-rich towards the top), which overlies diamictite of the Palestina Formation. These tw...
Principal component analysis (PCA) and mineral associations of litoraneous faci...
Marques, Wanessa Sousa; Sial, Alcides Nobrega; Menor, Eldemar de Albuquerque; Ferreira, Valderez Pinto; Freire, George Satander SáThe 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 Paraı´ba and Pernambuco, and clay minerals ...
Quimioestratigrafia dos Calcretes da Formação Xaraiés (MS)
Sial, Alcides Nobrega
Cloudina-Corumbella-Namacalathus association from the Itapucumi Group, Paraguay...
Warren, Lucas Verissimo [UNESP]; Quaglio, Fernanda; Simoes, Marcello Guimaraes [UNESP]; Gaucher, Claudio; Riccomini, Claudio; Poire, Daniel G.Made available in DSpace on 2018-11-26T17:40:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-09-01; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); PROPE - UNESP; The intriguing Ediacaran fossil Namacalathus is described from limestones of the Tagatiya Guazu Formation, Itapucumi Group, Paraguay. This is the fifth occu...
Neoproterozoic "tubestones" associated with microbialites in the southern Parag...
Sial, Alcides Nobrega
Carbon and oxygen isotope geochemistry of Ediacaran outer platform carbonates, ...
Sial, Alcides Nobrega
Geoquímica e gênese das formações ferríferas bandadas da formação Cauê, quadril...
Sial, Alcides Nobrega