Full text
| |
| Author(s): |
André Renan Costa Silva
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Rio Claro. 2018-11-30. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Geociências e Ciências Exatas. Rio Claro |
| Defense date: | 2018-10-05 |
| Advisor: | Giancarlo Scardia |
| Abstract | |
The northeast of Brazil presents an extensive geological history related to divergent tectonism and establishment of guide sequences through the separation of the South American and African continents during the Cretaceous. These events led to the formation of a set of sedimentary basins called the Interior Basins of Northeast Brazil, among which the group of sedimentary basins of lguatu or lguatu Group. The basins are comprised of a shallow sedimentary area with approximately 1135 km2, partially covered by the Orós and Lima Campos water reservoirs and strongly controlled by the Cariri-Potiguar trend and NE-SW proterozoic shear zones. lt is composed of the subbasins of lguatu, Malhada Vermelha, Lima Campos and lcó, filled by fluvial deposits and by fine to very fine sediments typical of floodplains, as well as distal channels and gravei bars distributed randomly. Evidence of a fluvial-aeolian interaction between rainy seasons forming architectural elements of fluvial systems and dry periods with dominance of aeolian processes can also be observed in the final stages of deposition. The sub-basin of lguatu, due to its favorable geomorphological scenario, works as a good stratigraphic guide for the application of the studies. Geological mapping, petrographic analysis, facies association and interpretation of structural elements, stablished four lithostratigraphic units for the lguatu Group: the lcó, Malhada Vermelha, Lima Campos and Orós Formations. Thermal demagnetization defined properties of the remanent magnetic field present in siltstones and mudstones of Malhada Vermelha and Orós Formations. Magnetostratigraphic columns estimate a Berriasian age (142.2 to 145.2 Ma) for the lcó Formation, representative of the final stages for the lguatu Basin. (AU) | |
| FAPESP's process: | 16/16537-1 - Stratigraphic analysis of the sedimentary basins of Iguatu, Ceará |
| Grantee: | André Renan Costa Silva |
| Support Opportunities: | Scholarships in Brazil - Master |