Publicação
The marine Neogene of Eastern Venezuela : a preliminary report
| Resumo: | The studied marine Neogene-Quaternary of NE Venezuela outcrop in the localities of the Araya peninsula and in the Cubagua and Margarita islands discordant upon a basementof metamorphic rocks and pre-rniocenic sediments. These neogene-quaternary sections belong principally to the Cubagua Formation, which is composed of a lower clayish interval (Cerro Verde Member) and an upper one of calcareous nature (Cerro Negro Member), and to La Tejita and Tortuga formations. The age of this sedimentary interval, based upon analysis of planktonic foraminifera, ranges from the lower part of Late Miocene to Holocene. According to the calcareous nannoflora, in the Cubagua Formation a floral assemblage was identified which goes from the Zone NN10 until the limit of NN16-NN17 zones. The fauna of benthic foraminifera allowed one to establish that the paleoenvironmental evolution of the Cubagua Formation varied from bathial to neritic depths during the Early Pliocene. After a period of elevation an erosion during the greater part of the Pleistocene, water invading the eroded surface depositing upon it the calcareous sequence of the Tortuga Formation. |
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| Autores principais: | Padron, V. |
| Outros Autores: | Martinell, J.; Domenech, R. |
| Assunto: | Neogene Quaternary Biostratigraphy NE Venezuela |
| Ano: | 1992 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade Nova de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório Institucional da UNL |
| Resumo: | The studied marine Neogene-Quaternary of NE Venezuela outcrop in the localities of the Araya peninsula and in the Cubagua and Margarita islands discordant upon a basementof metamorphic rocks and pre-rniocenic sediments. These neogene-quaternary sections belong principally to the Cubagua Formation, which is composed of a lower clayish interval (Cerro Verde Member) and an upper one of calcareous nature (Cerro Negro Member), and to La Tejita and Tortuga formations. The age of this sedimentary interval, based upon analysis of planktonic foraminifera, ranges from the lower part of Late Miocene to Holocene. According to the calcareous nannoflora, in the Cubagua Formation a floral assemblage was identified which goes from the Zone NN10 until the limit of NN16-NN17 zones. The fauna of benthic foraminifera allowed one to establish that the paleoenvironmental evolution of the Cubagua Formation varied from bathial to neritic depths during the Early Pliocene. After a period of elevation an erosion during the greater part of the Pleistocene, water invading the eroded surface depositing upon it the calcareous sequence of the Tortuga Formation. |
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