Acritarchs and prasinophytes from Amazonas Silurian basin: a good tool for the Trombetas Group biostratigraphic calibration
Autor(a) principal: | |
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Data de Publicação: | 2005 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | por |
Título da fonte: | Anuário do Instituto de Geociências (Online) |
Texto Completo: | https://revistas.ufrj.br/index.php/aigeo/article/view/6279 |
Resumo: | This paper deals with borehole data from 1.587,80-1.660,75 m interval of the well 1-AM-1-AM, which represents the most complete section of the Silurian in Amazon basin. Pitinga and Lower Manacupuru formations occurring in Petrobras cores T-40 to T-47 and in Eletronorte shallow boreholes SM 1015, SM 1016, SM-1018, SM-1047 and SM 10-48 were analysed. Besides Acritarch, Chitinozoa, Criptospores, Escolecodontia and amorphous organic matter were also recorded. The Silurian section is rich in well-preserved Acritarchs and prasinophytes, exhibiting a great diversity, mainly in the Pitinga Formation. Forty and eight species were classified. For each well, the Acritarch vertical distribution was done, the asociations age was discussed and the Chitinozoa-based dating, as established by (Grahn and Melo 1990), was compared. The informal division of the Pitinga Formation in lower and upper members was kept. The lower member (Telychian to Sheinwoodian) is represented mainly by Domasia limaciforme, D. Canadensis, D. trispinosa, D. amphora, D. rochesterensis, Dateriocradus monterrosae e Salopidium granuliferum, Cymbosphaeridium pilar, Dactylofusa tenuistriata, D. cucurbita, Deunffia furcata, Baltisphaeridium capillatum, Vibysphaera erratica, Micrhystridium intonsurans. The upper member (Gorstian) is separated from the lower by a hiatus, and is well defined by the following species: Deunffia furcata, D. brevispinosa, D. ramusculosa, Tyrannus giganteus, Eisenackidium ramiformis, Gorgonisphaeridium bringewoodense, Domasia bispinosa, D. trispinosa, Helios aranaides, Micrhystridium stellatum, Neoveryhachium carminae, Multiplicisphaeridium caperoradiola, Leiofusa kryanovii, Leiofusa filifera, Oppilatala insolita, Pterospermopsis marysae, Veryhachium rhomboidium, Cymbosphaeridium pilar, Cymbosphaeridium cf. ravum, Multiplicisphaeridium fisheri, Dactylofusa striatifera, Polysphaeritae, Visbysphaera microspinosa, Visbysphaera dilatispinosa, Salopidium wenlockensis and Veryhachium europaeum. According to Molyneux et al., 1996, most of the referred species such as Tyrannus giganteus and Perforela perforata are indigenous forms that were described in Upper Silurian from Spain and North Africa. Although these species could be excellent biostratigraphic markers, some of them still need a graptolitic correlation. For the basal Manacupuru formation, separated from Pitinga formation by a hiatus, the following species could be noted: Balthisphaeridium pilar, B. cariniosum, Multipliscisphaeridum saharicum, M. scaber, Domasia rochesterensis, Dateriocradus monterrosae, Neoveryhachium carminae and Perforela perorata. This association is considered to be Pridoli in age, which agrees with the Chitinozoa-based dating of Grahn & Melo (1990). Deunffia and Domasia are important taxa defining the Llandovery-Wenlock interval, of incontestable chronostratigraphic value, since they are restricted globally to the Silurian. According to (Cramer, 1970a; Le Hérissé, 1989; Molyneux et al., 1996) these taxa increase in number near the boundary between Llandovery-Wenlock, what is also confirmed in the present paper. |
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Acritarchs and prasinophytes from Amazonas Silurian basin: a good tool for the Trombetas Group biostratigraphic calibrationAcritarcos e prasinófitas do Siluriano da bacia do Amazonas: um poderoso auxílio na calibração bioestratigráfica do Grupo TrombetasThis paper deals with borehole data from 1.587,80-1.660,75 m interval of the well 1-AM-1-AM, which represents the most complete section of the Silurian in Amazon basin. Pitinga and Lower Manacupuru formations occurring in Petrobras cores T-40 to T-47 and in Eletronorte shallow boreholes SM 1015, SM 1016, SM-1018, SM-1047 and SM 10-48 were analysed. Besides Acritarch, Chitinozoa, Criptospores, Escolecodontia and amorphous organic matter were also recorded. The Silurian section is rich in well-preserved Acritarchs and prasinophytes, exhibiting a great diversity, mainly in the Pitinga Formation. Forty and eight species were classified. For each well, the Acritarch vertical distribution was done, the asociations age was discussed and the Chitinozoa-based dating, as established by (Grahn and Melo 1990), was compared. The informal division of the Pitinga Formation in lower and upper members was kept. The lower member (Telychian to Sheinwoodian) is represented mainly by Domasia limaciforme, D. Canadensis, D. trispinosa, D. amphora, D. rochesterensis, Dateriocradus monterrosae e Salopidium granuliferum, Cymbosphaeridium pilar, Dactylofusa tenuistriata, D. cucurbita, Deunffia furcata, Baltisphaeridium capillatum, Vibysphaera erratica, Micrhystridium intonsurans. The upper member (Gorstian) is separated from the lower by a hiatus, and is well defined by the following species: Deunffia furcata, D. brevispinosa, D. ramusculosa, Tyrannus giganteus, Eisenackidium ramiformis, Gorgonisphaeridium bringewoodense, Domasia bispinosa, D. trispinosa, Helios aranaides, Micrhystridium stellatum, Neoveryhachium carminae, Multiplicisphaeridium caperoradiola, Leiofusa kryanovii, Leiofusa filifera, Oppilatala insolita, Pterospermopsis marysae, Veryhachium rhomboidium, Cymbosphaeridium pilar, Cymbosphaeridium cf. ravum, Multiplicisphaeridium fisheri, Dactylofusa striatifera, Polysphaeritae, Visbysphaera microspinosa, Visbysphaera dilatispinosa, Salopidium wenlockensis and Veryhachium europaeum. According to Molyneux et al., 1996, most of the referred species such as Tyrannus giganteus and Perforela perforata are indigenous forms that were described in Upper Silurian from Spain and North Africa. Although these species could be excellent biostratigraphic markers, some of them still need a graptolitic correlation. For the basal Manacupuru formation, separated from Pitinga formation by a hiatus, the following species could be noted: Balthisphaeridium pilar, B. cariniosum, Multipliscisphaeridum saharicum, M. scaber, Domasia rochesterensis, Dateriocradus monterrosae, Neoveryhachium carminae and Perforela perorata. This association is considered to be Pridoli in age, which agrees with the Chitinozoa-based dating of Grahn & Melo (1990). Deunffia and Domasia are important taxa defining the Llandovery-Wenlock interval, of incontestable chronostratigraphic value, since they are restricted globally to the Silurian. According to (Cramer, 1970a; Le Hérissé, 1989; Molyneux et al., 1996) these taxa increase in number near the boundary between Llandovery-Wenlock, what is also confirmed in the present paper.O presente trabalho diz respeito ao estudo do poço 1-AM-1-AM no intervalo de 1.587,80m a 1660,75m que representa a seção mais completa da seqüência de sedimentos do Siluriano da bacia do Amazonas. Foram analisados ainda os testemunhos T-40 ao T-47, liberados pela Petrobrás bem como as sondagens rasas da Eletronorte SM 1015, SM 1016, SM 1O18, SM 1047 e SM 1048 pertencentes às formações Pitinga e Manacapuru (parte inferior). Foram encontrados além dos acritarcos, quitinozoários, criptósporas, escolecodontes e fragmentos de matéria orgânica. Na seção siluriana, o material exibiu elevado índice de abundância de acritarcos bem preservados e com grande diversidade, particularmente em sedimentos da Formação Pitinga. Quarenta e oito espécies de acritarcos foram classificadas. Para cada poço fez-se a distribuição vertical discutindo-se a idade das associações e comparando-as com as datações feitas com base em quitinozoários por Grahn & Melo (1990). De acordo com esses autores mantemos para a Formação Pitinga a divisão informal em membro inferior e membro superior. Para o membro inferior (Telychiano ao Sheinwoodiano), destacam-se principalmente: Domasia limaciforme, Domasia canadensis, Domasia trispinosa, Domasia amphora, Domasia rochesterensis, Dateriocradus monterrosae e Salopidium granuliferum, Cymbosphaeridium pilar, Dactylofusa tenuistriata, Dactylofusa cucurbita, Deunffia furcata, Baltisphaeridium capillatum, Visbysphaera erratica, Micrhystridium intonsurans. O membro superior (Gorstiano), apresenta-se bem definido e separado do membro inferior por um hiato, com as seguintes espécies: Deunffia furcata, Deunffia brevispinosa, Deunffia ramusculosa Tyrannus giganteus, Eisenackidium ramiformis Gorgonisphaeridium bringewoodense, Domasia bispinosa, Domasia trispinosa, Helios aranaides, Micrhystridium stellatum, Neoveryhachium carminae, Multiplicisphaeridium caperoradiola, Leiofusa kiryanovii, Leiofusa filifera, Oppilatala insolita, Pterospermopsis marysae, Veryhachium rhomboidium, Cymbosphaeridium pilar, Cymbosphaeridium cf. ravum, Multiplicisphaeridium fisheri, Dactylofusa striatifera, Polysphaeritae, Visbysphaera microspinosa, Visbysphaera dilatispinosa, Salopidium wenlockensis e Veryhachium europaeum. Segundo Molyneux et al.(1996) muitas dessas espécies tais como Tyrannus giganteus e Perforela perforata, são formas indígenas e que foram descritas no Siluriano Superior da Espanha e norte da África, que poderão ser bons marcadores bioestratigráficos mas a distribuição bioestratigráfica de muitos dessas espécies são imprecisas quando não existe avaliação feita com graptólitos. Para a porção basal da Formação Manacapuru separada do membro superior da Formação Pitinga por um hiato destacamos Baltisphaeridium pilar, B. cariniosum, Multiplicisphaeridium saharicum, M. scaber, Domasia rochesterensis, Dateriocradus monterrosae, Neoveryhachium carminae e Perforela perforata atribuída ao Pridoli, o que está de acordo com a datação de Grahn & Melo (1990) com base em quitinozoários. Deunffia e Domasia são taxa importantes que definem o intervalo Llandovery - Wenlock, cujo valor cronoestratigráfico é inegável uma vez que os mesmos restringem-se mundialmente ao Siluriano. Segundo Cramer (1970a); Le Hérissé (1989) e Molyneux et al. (1996), o registro desses taxa mostra um aumento em abundância próximo o limite Llandovery-Wenlock. O modelo biogeográfico de latitude paralela para os acritarcos do Siluriano segundo Molyneux et al. (1996) está sendo visto com certo ceticismo pelo fato de gêneros como Deunffia e Domasia, considerados de baixa paleolatitude terem sua ocorrência junto com formas de região paleoequatorial. De acordo com o modelo de distribuição de palinofáceis proposto por Cramer (1970) para o Siluriano, os acritarcos da bacia do Amazonas estariam situados no "Brazilian Realm" provavelmente na fácies Neoveryhachium carminae, caracterizada pela alta paleolatitude e clima frio e pela abundância de acritarcos do subgrupo Netromorphitae de Evitt (1963). Le Hérissé (1989) assinalou a ocorrência de Neoveryhachium carminae no Wenlock e Ludlow da Suécia em área de clima tropical (Palinofácies Báltica) durante o Siluriano. Isto contraria o modelo de zoneamento baseado em dados de paleolatitude paralela de Cramer (1970a, apud Cramer & Díez, 1972). O mesmo ocorre na bacia do Amazonas, que durante o Siluriano ocupou região de alta latitude. Temos ocorrência de acritarcos característico de baixa paleolatitude como Domasia amphora, Deunffia monospinosa e Tylotopala piramidalis, associadas à formas de alta paleolatitude como Dactylofusa maranhensis, Baltisphaeridium capillatum, Baltisphaeridium aniae, Tyrannus giganteus, e Perforela perforata. Fato também ocorrido no Llandovery superior da Jordânia, na bacia de Ghadames (Líbia) e na bacia Tindouf no oeste da Argélia, segundo (Molyneux et al., 1996).Universidade Federal do Rio de Janeiro2005-06-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://revistas.ufrj.br/index.php/aigeo/article/view/627910.11137/2005_1_131-142Anuário do Instituto de Geociências; Vol 28, No 1 (2005); 131-142Anuário do Instituto de Geociências; Vol 28, No 1 (2005); 131-1421982-39080101-9759reponame:Anuário do Instituto de Geociências (Online)instname:Universidade Federal do Rio de Janeiro (UFRJ)instacron:UFRJporhttps://revistas.ufrj.br/index.php/aigeo/article/view/6279/4876Copyright (c) 2005 Anuário do Instituto de Geociênciashttp://creativecommons.org/licenses/by/4.0info:eu-repo/semantics/openAccessCardoso, Tereza Regina MachadoRodrigues, Maria Antonieta da Conceição2022-10-13T17:44:46Zoai:www.revistas.ufrj.br:article/6279Revistahttps://revistas.ufrj.br/index.php/aigeo/indexPUBhttps://revistas.ufrj.br/index.php/aigeo/oaianuario@igeo.ufrj.br||1982-39080101-9759opendoar:2022-10-13T17:44:46Anuário do Instituto de Geociências (Online) - Universidade Federal do Rio de Janeiro (UFRJ)false |
dc.title.none.fl_str_mv |
Acritarchs and prasinophytes from Amazonas Silurian basin: a good tool for the Trombetas Group biostratigraphic calibration Acritarcos e prasinófitas do Siluriano da bacia do Amazonas: um poderoso auxílio na calibração bioestratigráfica do Grupo Trombetas |
title |
Acritarchs and prasinophytes from Amazonas Silurian basin: a good tool for the Trombetas Group biostratigraphic calibration |
spellingShingle |
Acritarchs and prasinophytes from Amazonas Silurian basin: a good tool for the Trombetas Group biostratigraphic calibration Cardoso, Tereza Regina Machado |
title_short |
Acritarchs and prasinophytes from Amazonas Silurian basin: a good tool for the Trombetas Group biostratigraphic calibration |
title_full |
Acritarchs and prasinophytes from Amazonas Silurian basin: a good tool for the Trombetas Group biostratigraphic calibration |
title_fullStr |
Acritarchs and prasinophytes from Amazonas Silurian basin: a good tool for the Trombetas Group biostratigraphic calibration |
title_full_unstemmed |
Acritarchs and prasinophytes from Amazonas Silurian basin: a good tool for the Trombetas Group biostratigraphic calibration |
title_sort |
Acritarchs and prasinophytes from Amazonas Silurian basin: a good tool for the Trombetas Group biostratigraphic calibration |
author |
Cardoso, Tereza Regina Machado |
author_facet |
Cardoso, Tereza Regina Machado Rodrigues, Maria Antonieta da Conceição |
author_role |
author |
author2 |
Rodrigues, Maria Antonieta da Conceição |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Cardoso, Tereza Regina Machado Rodrigues, Maria Antonieta da Conceição |
description |
This paper deals with borehole data from 1.587,80-1.660,75 m interval of the well 1-AM-1-AM, which represents the most complete section of the Silurian in Amazon basin. Pitinga and Lower Manacupuru formations occurring in Petrobras cores T-40 to T-47 and in Eletronorte shallow boreholes SM 1015, SM 1016, SM-1018, SM-1047 and SM 10-48 were analysed. Besides Acritarch, Chitinozoa, Criptospores, Escolecodontia and amorphous organic matter were also recorded. The Silurian section is rich in well-preserved Acritarchs and prasinophytes, exhibiting a great diversity, mainly in the Pitinga Formation. Forty and eight species were classified. For each well, the Acritarch vertical distribution was done, the asociations age was discussed and the Chitinozoa-based dating, as established by (Grahn and Melo 1990), was compared. The informal division of the Pitinga Formation in lower and upper members was kept. The lower member (Telychian to Sheinwoodian) is represented mainly by Domasia limaciforme, D. Canadensis, D. trispinosa, D. amphora, D. rochesterensis, Dateriocradus monterrosae e Salopidium granuliferum, Cymbosphaeridium pilar, Dactylofusa tenuistriata, D. cucurbita, Deunffia furcata, Baltisphaeridium capillatum, Vibysphaera erratica, Micrhystridium intonsurans. The upper member (Gorstian) is separated from the lower by a hiatus, and is well defined by the following species: Deunffia furcata, D. brevispinosa, D. ramusculosa, Tyrannus giganteus, Eisenackidium ramiformis, Gorgonisphaeridium bringewoodense, Domasia bispinosa, D. trispinosa, Helios aranaides, Micrhystridium stellatum, Neoveryhachium carminae, Multiplicisphaeridium caperoradiola, Leiofusa kryanovii, Leiofusa filifera, Oppilatala insolita, Pterospermopsis marysae, Veryhachium rhomboidium, Cymbosphaeridium pilar, Cymbosphaeridium cf. ravum, Multiplicisphaeridium fisheri, Dactylofusa striatifera, Polysphaeritae, Visbysphaera microspinosa, Visbysphaera dilatispinosa, Salopidium wenlockensis and Veryhachium europaeum. According to Molyneux et al., 1996, most of the referred species such as Tyrannus giganteus and Perforela perforata are indigenous forms that were described in Upper Silurian from Spain and North Africa. Although these species could be excellent biostratigraphic markers, some of them still need a graptolitic correlation. For the basal Manacupuru formation, separated from Pitinga formation by a hiatus, the following species could be noted: Balthisphaeridium pilar, B. cariniosum, Multipliscisphaeridum saharicum, M. scaber, Domasia rochesterensis, Dateriocradus monterrosae, Neoveryhachium carminae and Perforela perorata. This association is considered to be Pridoli in age, which agrees with the Chitinozoa-based dating of Grahn & Melo (1990). Deunffia and Domasia are important taxa defining the Llandovery-Wenlock interval, of incontestable chronostratigraphic value, since they are restricted globally to the Silurian. According to (Cramer, 1970a; Le Hérissé, 1989; Molyneux et al., 1996) these taxa increase in number near the boundary between Llandovery-Wenlock, what is also confirmed in the present paper. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005-06-01 |
dc.type.none.fl_str_mv |
|
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://revistas.ufrj.br/index.php/aigeo/article/view/6279 10.11137/2005_1_131-142 |
url |
https://revistas.ufrj.br/index.php/aigeo/article/view/6279 |
identifier_str_mv |
10.11137/2005_1_131-142 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.relation.none.fl_str_mv |
https://revistas.ufrj.br/index.php/aigeo/article/view/6279/4876 |
dc.rights.driver.fl_str_mv |
Copyright (c) 2005 Anuário do Instituto de Geociências http://creativecommons.org/licenses/by/4.0 info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Copyright (c) 2005 Anuário do Instituto de Geociências http://creativecommons.org/licenses/by/4.0 |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal do Rio de Janeiro |
publisher.none.fl_str_mv |
Universidade Federal do Rio de Janeiro |
dc.source.none.fl_str_mv |
Anuário do Instituto de Geociências; Vol 28, No 1 (2005); 131-142 Anuário do Instituto de Geociências; Vol 28, No 1 (2005); 131-142 1982-3908 0101-9759 reponame:Anuário do Instituto de Geociências (Online) instname:Universidade Federal do Rio de Janeiro (UFRJ) instacron:UFRJ |
instname_str |
Universidade Federal do Rio de Janeiro (UFRJ) |
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UFRJ |
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UFRJ |
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Anuário do Instituto de Geociências (Online) |
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Anuário do Instituto de Geociências (Online) |
repository.name.fl_str_mv |
Anuário do Instituto de Geociências (Online) - Universidade Federal do Rio de Janeiro (UFRJ) |
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anuario@igeo.ufrj.br|| |
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1797053535840370688 |