THE HISTORY OF THE MODERN MEDITERRANEAN BASIN MESOZOIC TO HOLOCENE

1. THE HISTORY OF THE MODERN MEDITERRANEAN BASIN MESOZOIC TO HOLOCENE

2. LOCATION OF PLACES DISCUSSED IN MANY MED “RECONSTRUCTION” PAPERS

3. Many of the Mesozoic carbonates we see in the Mediterranean (as seen during our Sicilian visit) developed on newly rifted continental margins that formed during the Mesozoic on the margins of both the northern and southern Tethyan seaway (see diagrams to follow for position of plates and their margins).

4. SICILY 180 Ma Toarsian-Aalenian MESOZOIC EVOLUTION OF THE TETHYS

5. SICILY CLEAR CENTRAL ATLANTIC OPENING BEGINS

6. INCIPIENT N. ATLANTIC RIFTING PYRENEAN SEA FLOOR NEW ALBORAN-BALEARIC OCEAN FLOOR SICILY NOTE SUSTAINED OPENING OF THE CENTRAL ATLANTIC

7. NORTH ATLANTIC SPREADING PYRENEAN CLOSURE SICILY SOUTH ATLANTIC OPENING

8. There were numerous depositional facies groupings developed upon these rifted zones (as seen at Rocca Busambra- on our last day in the field), commonly formed within diverse environments (see rift figures to follow). They were deposited within different areas and ALSO during DIFFERENT time periods during this rifting phase. For example the Sicani or Imerase chains of Sicily, discussed in the literature (studies by Catalano, and Lentini, for example) are representative of different parts of these rifted zones. Each chain (later tectonized) is different because the sediments formed on different parts of the rifted margin or at different times.

9. Fig. 10a. A panoramic view of the southern slope of Piano Pilato (Rocca Busandra) show- ing stepped faults and paleoscarps; INI= lower Liassic peritidal limestones; J= Jurassic deposits; b= Geological map of the area (Basilone, 2008).

10. (Basilone, 2008).

11. The following figures demonstrate how a rifted margin develops and why segments of it receive such different sediments.

12. DIKES, VOLCANOES VERY SIMPLFIED DIAGRAM ILLUSTRATING THE FIRST STAGE IN DEVELOPMENT OF A RIFT ZONE- MAGMA IS STARTING TO RISE ALONG A LINEAR RIFT ZONE WITHIN AN EXISTING CONTINENTAL ZONE (crust above initial rift is heated, uplifted, and stretched).

13. INITIAL HEATING DIAGRAM ILLUSTRATING MORE REALISTIC DEVELOPMENT OF FIRST STAGES OF RIFTING WITH TILTING OF RIFTED BLOCKS

14. OPENING OF A RIFT ZONE WITH DEVELOPMENT OF NEW OCEAN FLOOR- MAY REMAIN CONTINENTAL (WITH OR WITHOUT INFILLING LAKES) OR MAY BECOME FLOODED WITH MARINE WATER. SUBSIDENCE OF CONTINENTAL MARGINS IS RAPID, DUE TO THINNED, STRETCHED CRUST+ COOLING. THINNING IS PARTLY DUE TO STRETCHING, BUT ALSO TO EROSION OF UPLIFTED (older) CRUSTAL SEGMENTS.

15. ELONGATE LINEAR SEAWAY AMOUNT OF SUBSIDENCE AND TILTING OF BLOCKS IS UNEVEN, EVEN ALONG A SINGLE MARGINAL AREA.

16. DIAGRAM OF A MESOZOIC TETHYAN PASSIVE MARGIN “R” IS A REEF STRUCTURE (weakly bedded to massive) REEF MARGINAL AREAS (GREEN ARROW) USUALLY ARE WELL BEDDED. RED ARROW INDICATES AREAS OF REEFAL TALUS AND SLUMPS R 100 km YELLOW ARROW INDICATES PELAGIC PLATFORM BERNOULLI, 1981

17. TRIASSIC REEF FACIES, GRUPPE SELLE, ITALIAN ‘DOLOMITES’ ] FORE-REEF DEBRIS

18. REEF MARGIN DOWNSLOPE REWORKING R

19. OLISTOLITHS DEPOSITION AT THE BASE OF REEFS WITH ACCUMULATION IN GRABEN

20. REEFAL DEBRIS GRUPPE SELLE, REEFAL OLISTOLITH, AT THE BASE OF THE MARGINAL SLOPE

21. ASSOCIATED PELAGIC PLATFORM

22. OFFSHORE PLATFORM WITH PELAGIC DEPOSITION

23. More confusingly they have been affected by later compressional tectonics that emplaced many separate deposits (even of different ages) together into a confused heap during the Cenozoic compression. These many segments are now shoved one upon the other in grouped chains that developed from related segments of the old Tethys rifted margins.

24. PLATE MOTION (why Sicily is such a mess)

26. Figure3 Best fit for E. Mediterranean Best for Spain Best for Sicily/Calabria Position of Africa shown here presented with respect to Europe (for the past 175 Ma). Poles of rotation were worked out from magnetic position of Europe with respect to North America and then of Africa relative to North America. Rotation parameters were determined by comparing the finite difference solution of central and North Atlantic rotation parameters between the 2 areas. Then the motion changes of Africa with respect to Europe were directly related.

27. SUCCESSIVE PHASES OF MOTION OF THE NORTH AFRICAN COAST AFRICAN MOTION (early portion) LATER AFRICAN MOTION (eastern Mediterranean pivoting northward)

28. SEPARATE SEGMENTS OF PLATES CONSIDERED IN PLATE MOTION STUDY OF Dewey, Helman et al., 1989 Dewey, Helman et al. Were able to adjust the sense of rotation obtained from spreading motion based on detailed information obtained from each of the segments indicated above.

29. MESOZOIC CARBONATE PLATFORM C S OCEAN CRUST OCEAN CRUST SICILY SENSE OF MOTION SENSE OF MOTION ESTIMATED ANGLE OF ROTATION Dewey, Helman et al., 1989

30. C S OCEAN CRUST OCEAN CRUST SICILY ESTIMATED ANGLE OF ROTATION ESTIMATED ANGLE OF ROTATION Dewey, Helman et al., 1989

31. TORTONIAN C S OCEAN CRUST OCEAN CRUST SICILY Dewey, Helman et al., 1989

32. MESSINIAN C S OCEAN CRUST OCEAN CRUST OCEAN CRUST CALABRIA SICILY Dewey, Helman et al., 1989

33. PLIOCENE C OCEAN CRUST S OCEAN CRUST Dewey, Helman et al., 1989

34. C S Dewey, Helman et al., 1989

35. EVOLUTIONARY DIAGRAM SHOWING HOW THE STRUCTURES OBSERVED IN CALABRIA CAN BE RELATED TO THE SEQUENTIAL DEVELOPMENT OF THE APENNINE THRUST SYSTEM AND THE EXTENSION IN THE TYRRHENIAN SEA FLOOR.

36. Because Sicily is made up of different segments with diverse history, each segment responded to compression with different behavior. Also compression in the central and eastern Mediterranean changed direction about 9 Ma ago (see Dewey, Helman et al. Fig 3, as marked) so that much of the last phases of tectonism are about 90° rotated from the earlier stages.

37. DURING THE MESSINIAN THE MEDITERRANEAN BECAME A RESTRICTED WATER BODY BECAUSE INFLOW AND CIRCULATION OF MARINE WATER WAS LIMITED. SPORADIC PARTIAL DRAWDOWN PROBABLY TOOK PLACE. ROVERI et al., 2008

38. DEVELOPMENT OF THE MESSINIAN BASINS IN SICLY AND WHAT HAPPENED TO THE MESSINIAN MARGINAL SEDIMENTS DURING THE INCREASING SYNSEDIMENTARY TECTONISM AND BASINAL COMPRESSION

39. Cross-section A-A’ from previous figure - note development of sub-basins (west to east) and the different styles and degrees of reworking of the gypsum formed at the margins. ROVERI et al., 2008

40. REFERENCES Bernoulli, D. 1981. Ancient continental margins of the Tethyan Ocean. In:Geology of Passive Continental Margins. In: AAPG Education Course Note Series #19. Geology of Passive Continental Margins. Chapter 5, 36 pp. Basilone, L., 2008. Mesozoic tectono-sedimentary evolution of Rocca Busombra in western Sicily. Facies. V. 54: Cavazza, W. Roure, F., & Ziegler, P.A. 2004. The Mediterranean Area and the Surrounding Regions: Active Processes, Remnants of Former Tethyan Oceans and Related Thrust Belts. In: Cavazza, W. et al. “The TRANSMED Atlas”: Dewey, J. F., M. L. Helman, E. Turco, D. W. H. Hutton, and S. D. Knott .1989. Kinematics of the western Mediterranean. In: M. P. Coward, D. Dietrich and R. G. Park, eds.,Alpine Tectonics. Geological Society Special Publication 45. pp. 265-283 Roveri, M. , Lugli, S., Manzi, V., Schreiber, B.C. (2008) The Messinian Sicilian stratigraphy revisited: toward a new scenario for the Messinian salinity crisis. Terra Nova, 20, 1-6. Stamfli, G.M. and Borel, G., 2004. The TRANSMED Transects in Space and Time: Constraints on the Paleotectonic Evolution of the Mediterranean Domain. In: Cavazza, W. et al. “The TRANSMED Atlas”: 53-80.