Seismic stratigraphy as indicator of late Pleistocene and Holocene sea level changes on the NE Brazilian continental shelf
| Autor: | Karl Stattegger, Helenice Vital, Andre Giskard Aquino da Silva, Klaus Schwarzer |
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| Rok vydání: | 2016 |
| Předmět: |
Delta
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Pleistocene Continental shelf Geology 010502 geochemistry & geophysics 01 natural sciences Sedimentary depositional environment Paleontology Infill Submarine pipeline Geomorphology Holocene Sea level 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Journal of South American Earth Sciences. 70:188-197 |
| ISSN: | 0895-9811 |
| DOI: | 10.1016/j.jsames.2016.05.001 |
| Popis: | The late Pleistocene Holocene stratigraphic architecture on the northeastern Brazilian continental shelf off the Parnaiba Delta has been explored by high-resolution seismic profiles. The seismic surveys reveal the widespread distribution of incised valleys of different size in offshore continuation of the present-day Parnaiba delta. According to morphology two channel types can be distinguished: U-shaped channels in the eastern part and V-shaped channels in the western part. The stratigraphic successions were grouped into four seismic units separated by different seismic boundaries. The characteristics of the seismic boundaries and internal reflectors of the seismic units were used to distinguish between marine and riverine deposits. The incised-valleys architectural elements were used to link sedimentation processes and variations in base level from late Pleistocene channel avulsion and channel infill in the lowermost course of the paleo-Parnaiba River to marine sediments of the present-day inner shelf. The change of the depositional environments in relation to deglacial sea-level rise is compared to incised valley infills of the Mekong River and Red River systems in Southeast Asia. (C) 2016 Elsevier Ltd. All rights reserved. |
| Databáze: | OpenAIRE |
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