ELSEVIER Marine Geology 155 (1999) 9–43 The Betic orogen and the Iberian–African boundary in the Gulf of
The study of the Gulf of Cadiz on the basis of multichannel seismic profiles and wells illustrates the stratigraphy and tectonics. The evolution of the southern Iberian margins was more complex than in most North Atlantic margins since it entailed several phases of rifting, convergence and strike-sl...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
1997
|
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.378.7988 http://hera.ugr.es/doi/14997071.pdf |
| Summary: | The study of the Gulf of Cadiz on the basis of multichannel seismic profiles and wells illustrates the stratigraphy and tectonics. The evolution of the southern Iberian margins was more complex than in most North Atlantic margins since it entailed several phases of rifting, convergence and strike-slip motions. Three main tectonic provinces surround the internal zones of the Gibraltar Arc orogenic belt. These include in the Iberian margin of the Gulf of Cadiz the flysch units of the Campo de Gibraltar complex, the Betic External Zones, and the Neogene basins of the Guadalquivir Valley. Fault-bounded blocks of flysch and Subbetic units crops out over large areas of the southeastern Iberian shelf. The basement of the northwestern area, in contrast, is represented by the Paleozoic rocks of the Hercynian massif of Iberia. Half-graben structures determined the main structural trends of the margin during the Mesozoic, which were affected by inversion structures during the Neogene compressional stages. The Mesozoic and lower Cenozoic units are best observed in wells and seismic profiles from the northern area. These units are either obscure below a thick olistostrome deposit or are absent in most of the rest of the Gulf of Cadiz. Seven lithoseismic units from Triassic to Upper Oligocene and another seven Neogene and Quaternary units are identified based on the relationship to the depositional sequence and the emplacement of the olistostrome. The first tectonic phase was characterized by a passive margin, which was controlled by the development of half-graben extensional structures and carbonate platforms. This evolution comprises the Mesozoic |
|---|