Identificação, caracterização e interpretação de cordões litorâneos: integração de dados de radar de penetração do solo (GPR), análise de fácies e estratigrafia de sequência de alta resolução

Abstract

The identification and characterization of beach ridges in the subsurface in places where modern aeolian deposits cover the entire coastal plain is challenging. In this scenario, Ground Penetrating Radar (GPR) becomes the only method capable of detecting these deposits. In this context, 6 GPR profiles were acquired in the coastal plain of Malembá, west coast of Rio Grande do Norte. A beach ridge is identified in GPR profiles following two criteria: the external sigmoidal geometry of these bedforms and their internal radarfacies. This deposit can present two geophysical signatures in the GPR profiles: complete or incomplete (eroded). Eight radarfacies allow the delimitation of backshore, foreshore and shoreface beach regions were identified. The sigmoidal envelope of each beach ridge includes strata deposited in these regions. The comprehensive depositional model for beach ridges provides information on their distribution, depositional architecture, sequence stratigraphy, internal structures, and the impact of sea level fluctuations on the formation and preservation of these deposits. The study's findings may contribute to the understanding of beach ridges and their potential analogues to Brazilian pre-salt reservoirs and other beach ridge deposits worldwide.