The tectonic evolution of the Eastern Limassol Forest Complex, Cyprus

The Eastern Limassol Forest Complex (ELFC) lies at the southern margin of the Troodos ophiolite, Cyprus, and preserves a Penrose-type stratigraphy with a 4km-thick crustal sequence. The ELFC is separated from the main part of the Troodos Massif by an east-west trending fault zone, the Arakapas Fault Belt, which earlier studies suggest formed the northern wall of an oceanic transform fault. Transform-related structures are identifiable in the northern part of the ELFC, and volcaniclastic turbiditic sediments intercalated with lava flows attest to the existence of a bathymetric depression coincident with the fault zone. A southern boundary to the transform fault zone is recognised within the ELFC, with the abrupt disappearance of interlava sediments and E-W trending structures. Crust to the south of the boundary was generated at an 'Anti-Troodos' ridge axis. A width of c.5km is implied for the transform. The accretionary geometry of the ELFC has been extensively modified by postvolcanic tectonism. Sustained extension oblique to the trend of the transform has resulted in the reactivation of transform-related structures as normal faults, which have been rotated 'falling domino' style, together with the greater part of the axis sequence crust, above a decollement horizon located near to the petrological Moho. Extensional strain was preferentially accommodated in the transform-tectonised north of the ELFC. In the south, NW-striking normal faults are more steeply dipping, and block tilting is less extreme. Mesostructural data suggest that these normal faults have been reactivated as oblique dextral strike-slip faults and, with subsidiary NE-trending structures, are responsible for clockwise block rotations about steeply plunging axes. The timing of the deformation is constrained with respect to the overlying pelagic sediments, which suggest that the extension continued from the Turonian (i.e. almost immediately after ophiolite formation) to the late Campanian, and that the strike-slip reactivation occurred in late Campanian to early Maastrictian times. Palaeomagnetic studies have shown that Cyprus experienced a 90· anticlockwise rotation, which commenced in the Campanian-Maastrichtian interval, and it is argued that the late dextral strike-slip movements in the southern ELFC reflect deformation close to the margin of the rotating Cyprus microplate. The extensional reactivation of the transform in the Turonian-Campanian may correspond to an anticlockwise torque applied to the Troodos ocean floor prior to actual rotation. The rotation of Cyprus is thought to have been a consequence of the collision of the Arabian continental promontory to the east with an intra-oceanic subduction zone (above which Troodos was created) in the Upper Cretaceous