Quantitative approaches for big river deposits: integrated field geology and 3D photogrammetric models

Abstract

The process-product relationship in fluvial depositional systems is a fundamental issue on sedimentary geology, with implications for reservoir engineering, paleogeographical reconstructions and predictive models for mineral and hydrocarbon exploration. Nonetheless, the present day understanding of this relationship presents important limitations underpinned by the adequate description of active system and geological record components. Only recently, technological advances allowed the 3D investigation of sedimentary processes in the deepest parts of large-scale fluvial channels, as well as the survey of contemporaneous deposits and the description of large outcrops with reduced distortion imposed by scale. Thus, there is an urgent necessity to establish quantifiable descriptive parameters to compare the ancient fluvial Record and active fluvial systems, reconciling recent advances in sedimentology and rising demands from related sectors like reservoir engineering. In this way, the present proposal aims at the investigation of statistical distributions of sedimentological parameters in ancient fluvial successions ascribed to a large-scale fluvial system, allowing the comparison with statistical distributions of analogue parameters found in active fluvial systems through geophysical surveys. To accomplish this goal, an ancient large-scale river succession will be approached through integrated field geology and analysis of 3D outcrop photogrammetric models obtained with Unmanned Aerial Vehicles (UAVs). The expected results are methodological innovations on the description and interpretation of fluvial depositional systems, with potential implications for other areas within sedimentary geology. This research proposal is related to FAPESP research projects "Structure and evolution of the Amazonian biota and its environment: an integrative approach" (2012/50260-6) and "Characterization of heterogeneities and modeling of reservoir analogues in fluvial and eolian deposits" (2016/03091-5). (AU)