Quantification de la déformation associée à la faille active d'Aigion (golfe de Corinthe, Grèce) par l'étude des dépôts du Pléistocène supérieur et de la transgression marine holocène

A 205 m-deep borehole drilled in the Aigion harbour crosses three main sedimentary units: a lower deltaic unit, interbedded with lagoon brackish layers attributed to sea level high stands of marine isotopic stages 5 and 3, an intermediate brackish unit and an upper marine Holocene unit. Environmental conditions of sedimentation are determined by palaeontological studies. 14C ages and correlations with published sea level curves yield preliminary results on subsidence and sedimentation rates. Subsidence rates are close to those inferred from palaeoseismological studies (1.5-3.0 mm yr-1), whereas sedimentation rates are variable (1.5-13.8 mm yr-1). These rates will allow estimating the activity of nearby faults. © 2002 Académie des sciences/Éditions scientifiques et médicales Elsevier SAS.Un forage de 205 m situé à Aigion a traversé trois ensembles : un ensemble inférieur deltaı̈que, avec des passées saumâtres attribuables aux pulsations marines des stades isotopiques 5 et 3, un ensemble intermédiaire saumâtre et les dépôts de la transgression holocène. Des datations 14C accompagnent une étude paléontologique des sédiments, précisant les conditions de dépôt. Ces résultats permettent la comparaison avec les courbes de variation du niveau marin connues sur cette période. L'évolution des taux de subsidence (1,5–), proches de ceux obtenus par la paléosismologie, et des taux de sédimentation (1,5–) permettront d'estimer l'activité des failles voisines

Recent syn-rift deposits in the hangingwall of the Aigion Fault (Gulf of Corinth, Greece) [Dépôts syn-rift récents dans le compartiment toit de la faille d'Aigion (golfe de Corinthe, Grèce)]

Recent deep boreholes Γ1 (205 m) and AIG 10 (1001 m), performed in the Aigion area, bring new information on syn-rift deposits. MIS1/Holocène (11.8-4.3 ka BP) and Upper Pleistocene are identified in the upper part of the boreholes. Below Holocene deposits, the borehole AIG 10 crossed successively a detrital system with fine intercalations and a thick development of clay. No specific dating was possible on this lower formation, so the age of the local basal syn-rift deposits is discussed. © 2004 Académie des sciences. Published by Elsevier SAS. All rights reserved

Recent syn-rift deposits in the hangingwall of the Aigion Fault (Gulf of Corinth, Greece) [Dépôts syn-rift récents dans le compartiment toit de la faille d'Aigion (golfe de Corinthe, Grèce)]

Recent deep boreholes Γ1 (205 m) and AIG 10 (1001 m), performed in the Aigion area, bring new information on syn-rift deposits. MIS1/Holocène (11.8-4.3 ka BP) and Upper Pleistocene are identified in the upper part of the boreholes. Below Holocene deposits, the borehole AIG 10 crossed successively a detrital system with fine intercalations and a thick development of clay. No specific dating was possible on this lower formation, so the age of the local basal syn-rift deposits is discussed. © 2004 Académie des sciences. Published by Elsevier SAS. All rights reserved

The Ostracod fauna from the outcroup "la falunière" of Grignon (Lutetian, Paris Basin): Stratigraphical implications

International audienceThe rehabilitation of the outcroup "la falunière" of Grignon (shell marl pit) allowed for the first time to take an almost complete section of the Paris Basin Middle Lutetian under its uncimented facies. It was the opportunity to undertake sedimentological and paleontological studies. This publication presents results of the ostracode study. More than 6000 valves or carapaces were collected and 87 species was distinguished. Three new species are described: Paracypris keiji n. sp., Neocytherideis labyrinthoidea n. sp. and Grinioneis pachycosta n. sp. The ostracodes vertical distribution in the faluns of Grignon is probably without stratigraphical signification. On the contrary, the Lutetian ostracodes associations are characteristic, as well in comparison with those of the Ypresian that with those of the Auversian or of the Barton beds. Specific diversification reflects that of the environmental niches and the wealth in individuals testify of the abundance of the food. Ostracodes indicate that the Lutetian sea was shallow, from some decimetres to some metres, probably, and its waters limpid, not much agitated. The summer temperature of water was equal at least to that of present Mediterranean Sea. From a paleogeographic point of view, the similarity between gallic fauna seems much more narrow than between whatever of this gallic fauna and those of the Aquitanian basin; so, the majority of English Lutetian species are known in the Paris Basin while the proportion of common species of the Paris Basin and of the North Aquitain basin is weak. © Publications Scientifiques du Muséum national d'Histoire naturelle, Paris