Seismic Stratigraphy of the Tyrrhenian Sea (Western Mediterranean Sea) Based on ODP Leg Results: Consequences for the Basin Evolution

Jean Mascle, Jean-Pierre Rehault

A revision of the seismic stratigraphy of the Tyrrhenian Sea is based on detailed calibrations between a dense network of single-channel seismic reflection lines, about 2,000 km of recent multichannel seismic profiles, and the seven sites drilled within the Tyrrhenian in 1986 during the Ocean Drilling Program Leg 107. These correlations substantiate that the basin has been submitted to a succession of short-lived rifting episodes progressively shifting toward the southeast and leading to the local creation of discrete oceanic crust floored basins. Most of the Tyrrhenian basins and margins have been created in a very short time (between 8 and 2 m.y. in age) and are much younger than previously anticipated. Rifting processes have been acting on a very heterogeneous continen al basement (including several suture zones); drifting has created small oceanic subbasins also floored by a very heterogeneous magmatic basement (including serpentinized peridotites). The hypothesis of an asymmetric evolution facilitated by one or several crustal detachment fault systems and driven by geodynamic mechanisms of the bordering collision/subduction is considered.

AAPG Search and Discovery Article #91032©1988 Mediterranean Basins Conference and Exhibition, Nice, France, 25-28 September 1988.