| Titre | Precise chronology of Quaternary shoreline progradational sequences related to eustatic sea-level changes: sedimentation and subsidence in Saronikos Gulf, Greece |
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| Auteur | Foutrakis, P; Anastasakis, G; Piper, D J W |
| Source | Marine Geology vol. 428, 106278, 2020 p. 1-21, https://doi.org/10.1016/j.margeo.2020.106278 |
| Image |  |
| Année | 2020 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20200051 |
| Éditeur | Elsevier |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1016/j.margeo.2020.106278 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Région | Saronikos Gulf |
| Lat/Long OENS | 23.3344 23.9992 37.7878 37.3861 |
| Sujets | géochronologie; Sciences et technologie; géologie marine; sédimentologie; Quaternaire |
| Illustrations | cartes de localisation; diagrammes; tableaux; diagrammes |
| Diffusé | 2020 06 23 |
| Résumé | (disponible en anglais seulement)
The stacking patterns of shoreline progradational sequences in subsiding basins have been used as a chronologic tool in the Mediterranean region. Most previous
studies have used a few key seismic lines seaward of deltas, where the record is complicated by deltaic distributary switching. Southeastern Saronikos Gulf, in the western Aegean Sea at the northwestern end of the South Aegean Arc, lacks large river
input of sediment. The ENE-WSW and NW-SE trending neotectonic Aegina and Methana basins lie between the tectonically active Gulf of Corinth and the relatively stable Cyclades plateau. New high-resolution seismic profiles from southeastern Saronikos
Gulf have been interpreted according to the principles of seismic and sequence stratigraphy. Alpine basement and marine Pliocene sediments have been recognized in the surrounding basin margins and more than 300 m and 150 m of unconsolidated sediments
have been mapped in Aegina and Methana basin respectively. Progradational clinoforms that toplap against transgressive surfaces, have been traced along strike, leading to the establishment of a robust chronostratigraphic framework further controlled
by sedimentation rates as extracted from cores. Southeastern Saronikos Gulf poses an outstanding example of development of progradational wedges formed within a microtidal, wave dominated regime of low sedimentation rates, between 2.8 cm/ka and 3.2
cm/ka, within the framework of low subsiding basins with rates between 0.03 and 0.35 m/ka. In this environment, more than 180 well preserved shoreline progradational units, with attributes similar to the ones reported from the Aegean and Eastern
Mediterranean seas, have been mapped and correlated to sea level lowstands back to 866 ka. Deeper Mid-Pleistocene progradational units are also recognized, tentatively back to 1.4 Ma. Subsidence rate shows a dramatic decrease in the last 1 Ma and
significant numbers of faults became inactive during the last 130 ka. In Early-Middle Quaternary, Methana basin was an isolated lake and extended terrestrial areas were shaped in the Poros-Agios Georgios plateau during sea level lowstands. Aegina
basin was continuously connected to the Aegean through the Agios Georgios fault valley. This study demonstrates the robustness of chronology based on stacked shoreline progradational sequences and its applicability to determining rates of tectonic
subsidence. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Les fluctuations du niveau de la mer au cours du dernier million d'années laissent une trace d'accumulation de sédiments sur les plateaux
continentaux subsidents qui ont un apport sédimentaire uniforme. Cette étude décrit ce phénomène en mer Méditerranée et ses répercussions sur la compréhension de l'histoire mondiale des changements du niveau de la mer. |
| GEOSCAN ID | 326078 |
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