Ground Penetrating Radar investigation of depositional architecture: the São Sebastião and Marizal formations in the Cretaceous Tucano Basin (Northeastern Brazil)

• Main Authors: Larissa Natsumi Tamura, Renato Paes de Almeida, Fabio Taioli, André Marconato, Liliane Janikian
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Geologia
• Series: Brazilian Journal of Geology
• Subjects: radar fácies; Radar de Penetração no Solo; sistema fluvial; Formação São Sebastião; Formação Marizal.
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892016000100015&lng=en&tlng=en

ABSTRACT: One key factor for the advance in the study of fluvial deposits is the application of geophysical methods, being the Ground Penetrating Radar one of special value. Although applied to active rivers, the method is not extensively tested on the rock record, bearing interest for hydrocarbon reservoir analogue models. The São Sebastião and Marizal formations were the subject of previous studies, which made possible the comparison of Ground Penetrating Radar survey to previous stratigraphic studies in order to identify the best combination of resolution, penetration and antenna frequency for the studied subject. Eight radar facies were identified, being six of them related to fluvial sedimentary environments, one related to eolian sedimentary environment and one radar facies interpreted as coastal sedimentary environment. The Ground Penetrating Radar data showed compatibility to sedimentary structures in the outcrops, like planar and trough cross-stratified beds. It is noted that the obtained resolution was efficient in the identification of structures up to 0.3 m using a 100 MHz antenna. In this way, the Ground Penetrating Radar survey in outcrops bears great potential for further works on fluvial depositional architecture.