La depresión periférica y el lomo contourítico de Menorca: evidencias de la actividad de corrientes de fondo al N del Talud Balear

Abstract

A peripheral depression with a sediment drift on its N flank develop N and E of Minorca Island. Both are interpreted to result from the activity of bottom currents circulating parallel to the base of the island slope since the Pliocene. Evidences of the contouriric activity are: the presence of a depression with an erosive character, a sedimentary ridge with the typical characteristics of contourite drifts, and large sediment waves. The depression has a maximum width of 5 km, and a depth of 150-200 m, whereas the contourite drift reaches up to 150 km in length, is 25 km wide, and 100 m high. The sediment waves developed on the inner flank of the contourite drift reach up to 5 km in length and 40 m in height. The genesis of all these structures is related to the circulation of the Mediterranean Deep Water ( MDW) in the area. The steep island slope, devoided of sediment and deeply gullied, is considered as the potential source area for the sediments reworked by the currents. Further seaward, the contourite deposits are in lateral continuity with the deposits of the North-Balearic Basin and the Valencia Fan