Comparative analysis of modern fluvial systems and the rock record: outcrop-scale ...
| Grant number: | 06/02381-8 |
| Support type: | Scholarships in Brazil - Master |
| Effective date (Start): | September 01, 2006 |
| Effective date (End): | August 31, 2008 |
| Field of knowledge: | Physical Sciences and Mathematics - Geosciences |
| Principal Investigator: | Mario Luis Assine |
| Grantee: | Hiran Zani |
| Home Institution: | Instituto de Geociências e Ciências Exatas (IGCE). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil |
Abstract The Taquari alluvial megafan is a multi-fan depositional system. The system covers 37% of the total Pantanal area and displays a circular geometry and a length of 250km from the apex to the toe. Three subsystems characterize the natural landscape: a meander belt in the upper fan; an active depositional lobe in the middle and lower fan, and several abandoned lobes with intricate network of paleochannels. The key to establishment future landscape changes it to document relict forms and to understand the shifting processes that have occurred. In this prospective view, the main purpose in the Pantanal area is to know how the alluvial fan system works. In this way it is important to recognize the temporal succession of fan lobes. Several techniques and methods of analysis can and have to be applied to reach this goal. In this project it is intended to carry out an analysis based on the use of remote sensing techniques and methods, such as the interpretation of satellite images Landsat TM and the elaboration of digital models of elevation (MDE) using images SRTM-3. The interpretation is based on the fact that the paleochannels of older lobes are truncated by the paleochannels of the new ones, which represent morphologic criteria to identify the relative chronology. Besides, it is postulated that the new lobes tend to be topographically higher than the old ones because they are less compacted and less dissected by erosive agents such as surface waters and wind. The interpretations will be checked by direct observation in field work campaign, when samples will be collected to accomplish sedimentological analysis in order to characterize the sediment properties of distinct lobes. Finally, the results will be compared with features described in other megafans, searching for analogies and models of lobe construction and abandonment. The expectation is to build an evolutionary model that can be used to forecast new landscape changes in the Pantanal area and that can serve as a model in the study of modern and ancient alluvial fan systems. | |