Overview of palaeogeography and processes of rifting and continental break-up in the E Mediterranean region of E Tethys

Author(s): Robertson, Alastair
Author Affiliation(s): Primary:
University of Edinburgh, School of GeoSciences, United Kingdom
Volume Title: 33rd international geological congress; abstracts
Source: International Geological Congress [International Geological Congress, Abstracts = Congrès Géologique International, Résumés, Vol.33; 33rd international geological congress, Oslo, Norway, Aug. 6-14, 2008. Publisher:], [location varies], International CODEN: IGABBY
Note: In English
Summary: In contrast to the N Atlantic and W Tethyan (Alpine) region continental break-up in the Eastern Tethys, exemplified by the E Mediterranean, was associated with extensive rift-related volcanism (e.g. up to 1 km thick in SW Turkey). The E Tethys is characterised by rifting of continental fragments from Gondwana, while Tethys subducted beneath Eurasia far to the north. In the east (Oman, Iran) spreading began by Late Permian time, whereas in the E Mediterranean there is no record of break-up until Late Triassic time. In Turkey, the Tauride-Anatolide platform rifted as a palaeogeographically complex unit, with the small Kirşehir continent further north. In and around Greece the S Serbo-Macedonian/Paikon, Pelagonian and Vardoussia units rifted as variably sized continental fragments. The Pelagonian microcontinent extended westwards through Albania (Korabi unit) bounded to the south by Adria (Apulia), itself a large microcontinent detached from N Africa. West of the Scutari-Pec lineament the palaeogeography changed with existence of the Kapaonik and Drina-Ivanica continental units bordered by Adria to the south. In Iran, one or several microcontinents collided with Eurasia by latest Triassic time. Further west, the S Serbo-Macedonian/Paikon block accreted to Eurasia by "mid-Mesozoic time". Other microcontinents collided with intra-oceanic subduction zones during Late Middle Jurassic in the "Greek region" and Late Cretaceous in the "Turkish" region, associated with ophiolite emplacement. Microcontinents assembled to Eurasia or Gondwana (N Africa) when E Tethys finally closed during Early Cenozoic-Pliocene in different areas. A plausible mechanism of Triassic continental break-up was plume-influenced rifling, coupled with slab-pull beneath Eurasia. One alternative is that many, or all, of the "microcontinents" are simply windows through far-travelled thrust sheets to a regional continental foreland. However, this falls foul of numerous local and regional tectonostratigraphic constraints. Another is that some microcontinental units rifted when Triassic back-arc basins opened behind subduction zones (e.g. Beyşehir in Turkey; Pindos and Vardar in Greece). Against this, the regional geology differs strongly from well-documented modern and ancient backarc basins. In particular, there is an absence of coeval or pre-existing related magmatic arcs. A localised subduction-chemical imprint (e.g. negative Nb anomaly on MORB-normalised spider plots) in some Triassic rift basalts (e.g. S Pindos; NW Tauride) is explicable by the effects of inherited (Hercynian) subduction, as documented from the rifted margin of the NW Atlantic (ODP Leg 210).
Year of Publication: 2008
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; 18 Geophysics, Solid-Earth; Adriatic Plate; Albania; Asia; Atlantic Ocean; Back-arc basins; Basins; Cenozoic; Eurasia; Europe; Gondwana; Iran; Leg 210; Mantle plumes; Mesozoic; Microcontinents; Middle East; Newfoundland Basin; North Atlantic; Northwest Atlantic; Ocean Drilling Program; Ophiolite; Paikon Massif; Paleogeography; Plate tectonics; Rifting; Scutari-Pec Lineament; Serbo-Macedonian Massif; Southern Europe; Subduction zones; Tauride-Anatolide Platform; Tethys; Thrust sheets; Turkey; Volcanism
Coordinates: N451000 N453000 W0442000 W0450000
Record ID: 2012046376
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