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Interpretation of structural and major drainage systems studied and interpreted by means of remote sensing techniques employing SAC-C and LANDSAT TM 5 images. South América
Results
Visual interpretation led us to determine several major structural lineaments directions. This is classical in the specialized literature so we will not describe now these structures.
On the contrary, our study, outstandingly, led us to determine several initial and pre-initial rifting system style assemblage models (relatively modern earth elements), all of these corresponding to very well exposed extensional-rotational fracturing model (stretching earth crustal thickness).
So, we can appoint the Paraná river rift basin as a typical model.
The Paraná river rift basin system, the Paraguay river rift system and the Uruguay river micro-rift initial breaking cortical processes were outlined. The Orinoco rifting framework, the Guyana-Suriname rifting system as well as the Amazonic large rift basin were delimited.
These structures have several strikes due a response to the re-accommodation of the South American microplates. The study of these microplates is in progress at present time using satellite imagery.
Model of drainage system depends on the scale of observation.
In our case, at the plains areas (60 in percentage of the plains) they are classical dendritic-form models due to isotropic condition in the soils.
The rivers controlled by rifting are lineal.
Conclusions
In this study, based on interpretation of satellite data, we were able to determine relation between drainage and tectonic assemblages at regional-continental scales.
It was possible to determine first and second order structural basin lineaments as the rift model and detect several initial breaking continental processes as the micro-rift initial system of the Uruguay and Guyana-Suriname regions.
All of these tectonic structures are related to cortical stretching processes of the lithospherical bed.
The SAC – C images employing the multispectral medium resolution scanner system (MMRS) proved to be a suitable tool to continental and regional studies in spite of their size pixel in the standard mode (175 m).
Many interpretations were possible made trough the help of Landsat TM 5 images which were a better spatial resolution in the thematic mapper sensor (30 m).
So, more detailed studies require a more sophisticated hardware and software as well as satellite imagery of very high spatial resolution.
References
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- MORELLO, J. & ADAMOLI, J. 1974, La Vegetación de la República Argentina. Las Grandes Unidades de Vegetación y Ambiente del Chaco Argentino. Segunda Parte: Vegetación y Ambiente de la Provincia del Chaco. Centro Nacional de Investigaciones Agropecuarias. Instituto de Botánica Agrícola. Serie Fitogeográfica No 13. Buenos Aires. 124 p.
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- TORRA, R. 2005, The Chaco Paraná Basin rift system. An approach to the tectonic-stratigraphical evolution from the Late Cretaceous to Quaternary. South America. Ciência e Natura. 27 (2): 25-64
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