The SIMBAD project : Messinian markers and recent deformation in the Balearic Region A. Maillard 1, V. Gaullier 2, F. Sage 3, F. Chanier2, J. Lofi 4, A. Briais 1 , D. Ochoa5

1.GET-OMP, UMR 5563, CNRS-UPS-IRD, 31400 Toulouse, ([email protected]) ; 2. Université de Lille 1, UMR 8157, Cité Scientifique -Batiment SN5, 59655 Villeneuve d'Ascqdex, Fcerance ; 4. Géosciences Montpellier Université Montpellier II 34095 Montpellier Cedex 05, France ; 41°N The SIMBAD Project aims to study the sedimentary deposits linked to the Messinian Salinity Crisis (MSC) on the Balearic Pro- 5. Departamento de Geología Universidad de Facultad De Ciencias 37008 Salamanca montory in order to : > follow their continuity from land and shallow areas to deep basins (spatial variability of the evaporites) dsdpsit e 123 SPAIN dsdp esit 122 > use the MSC markers to evaluate their paleo-connections and quantify the post-MSC tectonic reactivation. dsdpsit e 372

ESE 40°N BASIN NW MINORCA 0.2 F69 e multipl 0 5 km WSW 0.4 435 Valencia salt deformation. MALLORCAFig4 0.6 T SOUTH

W CHANNEL s( T ) 404 Fig6b 39°N Central Mallorca 0.8 1.5 Depression ENT

) 0 5 km

s

( TWT ( BUt PARPM dsdpsit e 975 multiple Fig6a IBIZA ES SE 1.0 betic BLOCK dsdpsit e 124 Pre T Fig3 2.0 gypsum and anhydrite 334 497

rigging artefacts ? e Fig2 CHANNEL EMILE BAUDO

TWT (

Figure 3. SIMBAD 13 from the Mallorca slope to the Mallorca Central Depres- )s multipl CALPE etic sion, showing the varability of the MSC unit. Plastic deformation occurs on the 38°N 410 Figure 2 : SIMBAD 26 on the Alicante shelf showing the Subb

iF borders of the Depression and a transparent seismic facies below BU show evi- g Base Pliocene isobaths 5 MES extension (top MSC deposits when present) correlation of the evaporites unit of the Calpe well with MES limit 1000 : contour interval in meters dences for a salt layer (MU), ranging 2000m shallower than the deep basin MU nal Betic Inter BU extension Volcanoes the BU., nicely eroded on top ENT thick BU limit Sierras on the Islands MAZARRON ESPARPM UU extension Industrial wells

NW SE ALGERIAN BASIN MU extension (below UU) MSC markers DSDP sites White lines : SIMBAD profiles PLIO-QUATERNARY SEQUENCE PRE-MSC POST-RIFT SEQUENCE PRE-RIFT SUBSTRATUM 2°W 1°W 0°E 1°E 2°E 3°E 4°E 5°E 0 5 km Strike-Slip Fault MES: Margin Erosion Surface BU: Bedded Unit 37°N IntraPliocene Discontinuities MSC TS: Top Surface UU: Upper Unit Figure 1. Present day extension map of the MSC units of the Balearic area. The thin MSC units on the 1.0 SURFACES TES: Top Erosion Surface MSC UNITS MU: Mobile Unit

BS: Bottom Surface LU: Lower Unit Promontory between Alicante shelf and Mallorca are called BU (blue) though they ressemble UU, because

TWT ( s BES: Bottom Erosion Surface ) CU: Complex Unit they cannot be surely connected to the surrounding UU. Either a horst prevents the connection either data

1.5 is laking in the localised area (channels). On the Minorca block, the MSC unit present is clearly the conti- The SIMBAD cruise (January2013 ) that ac- nuity of the UU of the deep basin (trilogy present in the Algero-Provencal basin).

Figure 4. SIMBAD 16 from the centre of the Mallorca Central Depression, quired high resolution seismic profilesprovi des evidence of the thin a Xabia Seamount Folded bathymetry and MSC unit showing recent extensionnal tectonics that offset the MSC unit. Most of the MSC deposits widespread on the Balearic Promontory, at Present day 10km faults seems to be Pliocene in age but also 1.0 Pre-MSC fault are clearly reactivated during Pliocene or actually. ranging from 500 to 2500m.question It s the occurenceof only “deep” versus “marginal” evaporites types. 2.0

0 3.0 Ibiza Channel 0 NW SE UU/CU BU b 1 1 Pliocene-Pleistocene unit 2 8° North dipping 12° South dipping UU above MU 2 Tortonian reef unit 3 3

TWT (s) 4 Betic thrusts 4 30m 5 v v v 5 oceanic crust 5 Figure 6. Kilometric scale flexure showing recent reactivation MAP144 v v v v v 6 MAP86 v where Betic thrusts occured in the Ibiza channel (a). Same kind Figure 5. Cross-section along the Ibiza channel showing the variabilty of the MSC unit. As observed, the MSC unit is present in the Ibiza channel within small basins between eroded areas (Xabia of flexure affects the Tortono-Messinian reef surface (b, Portinatx Seamount). The relation with the deep basins is complicated as recent tectonics offset both the Balearic BU and the Valencia and Algerian UU. A paleo-connection between the different MSC units bay, NE Ibiza Island). before the recent reactivation is conceivable.