Application of shallow seismic profiling to study riverbed architectural facies: a case study of the Tocantins river (Pará - Brazil)

Anais da Academia Brasileira de Ciências

Marco Ianniruberto¹  José E.g. Campos¹  Vitto C.m. Araújo¹ 

[1] ,Universidade de Brasília Instituto de Geociências Brasília DF ,Brasil

关键词: anastomosed rivers;    alluvial sedimentology;    architectural facies;    stratigraphy;    high-resolution seismic;    rio entrelaçado;    sedimentologia fluvial;    feições arquiteturais;    estratigrafia;    sísmica de alta resolução;   

DOI  :  10.1590/S0001-37652012000300007

来源: SciELO

【 摘 要 】

To date, the vast majority of river sedimentology study has relied on two main categories of observation: direct observation of shallow trenches, cut faces and cores or geophysical survey on dry and shallow regions of braid bars. In this study, a sub-bottom profiler was used to investigate the stratigraphy of the lower course of the Tocantins River in the Amazon region, between the city of Tucuruì and the village of Nazaré dos Patos. The interest in this specific region lies on the possible variation of the fluvial regime due to the installation of the dam of the Tucuruì hydroelectric plant and the perspective that such river would become navigable as soon as the canal lock will be completed. Collected data show a detailed variety and complexity of architectural elements, as well as internal structure of sandy macroforms. Furthermore, the results allowed the identification of three main environments linked to channel sedimentation processes: by-pass, transition and deposition environments, whose distribution is linked to channel dynamics and bedrock topography. The application of the study is manifold, once it provides not only an insight into sedimentary structure of alluvial forms and sedimentation history, but also elements demanded to plan eventual engineering works for river navigability.

【 授权许可】

CC BY   
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