Mário Lima Filho

First Ediacaran Fauna Occurrence in Northeastern Brazil (Jaibaras Basin, ?Ediacaran-Cambrian): Preliminary Results and Regional Correlation

This study reports the first known occurrence of the Ediacaran fauna in northeastern Brazil (at Pacujá Municipality, northwestern state of Ceará) and presents preliminary interpretations of its significance. Regional correlation indicates that the fossils originated in the Jaibaras Basin and that they may represent a new geological system. The depositional environment can be attributed to a fluviomarine system. Nine Ediacaran species can be identified, including members of pandemic groups (e.g., Charniodiscus arboreus Glaessner, 1959; ?Charniodiscus concentricus Ford, 1958; Cyclomedusa davidi Sprigg, 1947; Ediacaria flindersi Sprigg, 1947; and Medusinites asteroides Sprigg, 1949) and endemic groups (e.g., Kimberella quadrata Glaessner & Wade, 1966; Palaeophragmodictya reticulata Gehling & Rigby, 1996; Parvancorina minchami Glaessner, 1958; and Pectinifrons abyssalis Bamforth, Narbonne, Anderson, 2008). Three ichnogenera are also present: Arenicolites Salter, 1857; Palaeophycus Hall, 1987; and Planolites Nicholson, 1873. The relative age of the deposits is between ?Ediacaran and Cambrian, and the fauna resembles the White Sea Assemblage. The bioturbation presents typical unbranched Ediacaran ichnogenera with little depth in the substrate. This previously unknown occurrence of the Ediacaran fauna reinforces the importance of the state of Ceará to Brazilian and global palaeontology.

Dente de um picnodontiforme (Actinopterygii, Neopterygii) da Formação Estiva, Cenomaniano-Turoniano da Bacia de Pernambuco, NE do Brasil

Ray-finned fishes (Actinopterigii) pycnodontiformes compounds a specialized group, small to medium-sized, with laterally compressed body and a batteries of flattened, peg-like teeth on the vomer, adapted for feeding on hard-shelled prey and by its life in near shore environments and/or characterized by reefs. Here is presented their first record to the carbonate deposits included in Estiva Formation, Maracaipe region, in the south of coastal Pernambuco Basin, considered Cenomanian-Turonian in age, where is also the first evidence of vertebrate rests. The record of fish remains open new perspective to this stratigraphic unit and to the basin in general, until the moment poorly known. Key words: pycnodontiformes, Cretaceous, Pernambuco Basin, Estiva Formation.

GEOLOGIA DA PORÇÃO CENTRO-LESTE DA BACIA SÃO JOSÉ DO BELMONTE, PERNAMBUCO, NE DO BRASIL

Este trabalho apresenta os resultados do mapeamento geologico em escala 1:50.000 de uma area de 350 Km2 na porcao centro-leste da Bacia de Sao Jose do Belmonte, localizada entre os municipios de Verdejantes e Sao Jose do Belmonte - PE. Utilizando aspectos de campo, analises petrograficas e bioestratigraficas, foram cartografadas sete unidades litoestratigraficas, quatro delas pertencentes ao embasamento da bacia: o Complexo Sao Caetano, composto por paragnaisses intercalados com quartzitos; o Complexo Riacho Gravata, formado por rochas metapeliticas, metavulcânicas e quartzitos; sienitos milonitizados; e rochas graniticas. As unidades sedimentares incluem a Formacao Cariri, composta por conglomerados e arenitos grossos a medios; a Formacao Brejo Santo, que compreende folhelhos e argilitos; e a Formacao Missao Velha, composta por arenitos grossos a finos. Bioestratigrafia baseada em ostracodes nao marinhos em folhelhos vermelhos obtiveram especie-guia da biozona NRT-001 (Andar Dom Joao), idade Jurassico Superior, o que permitiu correlacionar esses depositos a Formacao Brejo Santo da Bacia do Araripe, e assim posicionar as demais unidades. Estruturalmente, os metapelitos do complexo Riacho Gravata apresentam foliacao de baixo ângulo com transporte tectonico para SW. Rochas sieniticas com textura milonitica e foliacao subvertical evidenciam tectonica transcorrente associada a zona de cisalhamento Sao Jose do Belmonte. Tanto as rochas graniticas, como as rochas sedimentares apresentam falhas sinistrais de direcao N e NNE e falhas destrais de direcoes ENE e NNW.