Abstract:
SRTM-derived slope models were analyzed to find sediment storage zones in Jequitaí hydrographic basin. Those data provided the identification of an anomalous drainage site located at Jequitaí basin`s eastern portion between Espinhaço and Cabral ranges. Some contrasts of sedimentation pattern and valley cross-section along a short segment of Gameleira stream are good examples of these anomalies. Regional litho-structural analysis, including Cenozoic deformations, suggests that local variations of the Paraopeba Subgroup components are the main responsible for the observed fluvial system evolution. In addition, the northward tilting of Jequitaí basin`s southern portion, in the Jequitaí graben direction, increase the anomalous litho-structural effects. Log profiles suggest that alluvial fans coming probably from Espinhaço range covered the research sites. This work shows that some non-erosive fluvial segments can be mistakenly explained as agradational. The studied segment presents morpho-sedimentary attributes that reflect the local geodiversity setting, where predictions are very difficult.
Keywords:
drainage anomaly; litho-structural control; geodiversity