HR: 1330h
AN: V32C-1030    [PDF]
TI: Long-term Landscape Evolution of the Ligurian Alps (NW Italy)
AU: * Foeken, J
EM: jurgen.foeken@falw.vu.nl
AF: Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, 1085HV Netherlands
AU: Bertotti, G
EM: giovanni.bertotti@falw.vu.nl
AF: Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, 1085HV Netherlands
AU: Sormani, L
EM: lsormani@ogs.trieste.it
AF: PROS Group, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, Trieste, 34010 Italy
AU: Wardell, N
EM: nwardell@ogs.trieste.it
AF: PROS Group, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, Trieste, 34010 Italy
AU: Dunai, T
EM: tibor.dunai@falw.vu.nl
AF: Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, 1085HV Netherlands
AU: Andriessen, P
EM: paul.andriessen@falw.vu.nl
AF: Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, 1085HV Netherlands
AB: The long-term landscape evolution of the Ligurian Alpine system (NW Italy), covering the onshore Ligurian Alps and the offshore Ligurian basin, has been reconstructed integrating detrital apatite (U-Th)/He and fission track (AFT) data with results from seismic studies. Three transects, covering the onshore western, central and eastern Ligurian Alps have been investigated. Both apatite He and AFT ages become older eastwards, documenting late Miocene cooling in the western Ligurian Alps (Foeken et al., 2003), while early to middle Miocene cooling is recorded in the eastern Ligurian Alps. Cooling is interpreted to result from exhumation accommodated along a north dipping thrust front emerging oblique to the Ligurian margin. Three seismic lines describe the offshore evolution of the Ligurian basin. Main results from the seismic study are that the late Miocene to recent sequences are characterised by continuous reflectors that lack deformation. The apparent discontinuity between the ongoing exhumation onshore and the tectonic quiescence offshore suggest that the two systems are detached. Analysis of the seismic lines shows that following the Pliocene, the Liguro-Proven‡al basin experienced subsidence, resulting in a deepening of the basin. Reconstruction of the Pliocene to recent morphology of the Ligurian Alpine system shows that the long-term evolution is directly related to movement along the thrust front. The western Ligurian Alps, evolving from moderate relief in the Pliocene to steep relief with well-incised valleys at present day, is located close to the actual thrust front and experiences active exhumation. The eastern Ligurian Alps, located northwards and away from the thrust front, is characterised by low to moderate relief from the Pliocene to present day. Foeken, J.P.T., Dunai, T.D., Bertotti, G., and Andriessen, P.A.M., 2003, Late Miocene to present exhumation in the Ligurian Alps (southwest Alps) with evidence for accelerated denudation during the Messinian salinity crisis: Geology, v. 30, p. 797-800.
DE: 1035 Geochronology
DE: 1040 Isotopic composition/chemistry
DE: 1815 Erosion and sedimentation
DE: 8102 Continental contractional orogenic belts
DE: 8105 Continental margins and sedimentary basins
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting