The spreading structure of the Solea Graben, Troodos Ophiolite, Cyprus

Field studies show that extensional structures in the north-central part of the Troodos Ophiolite, including steep normal faults, grabens, dikes and low-angle detachment faults are related to east-west (present coordinates) spreading. The Solea graben, directly north of the mafic-ultramafic rock outcrops around Mount Olympus, consists of a 10 to 15 kilometer wide western portion that is underlain by a low-angle detachment fault between the sheeted dike complex and the plutonic section. Structural and paleomagnetic evidence indicates that the sheeted dikes above this detachment have been rotated more than 40 degrees about subhorizontal axes. The eastern portion of the graben contains sheeted dike blocks with varying axes of rotation, including some very steep axes, and significantly different style of intrusive activity. Most structural features in the graben formed simultaneously with or shortly after cessation of spreading at the graben axis. Timing of the uplift of the central part of the Troodos Ophiolite is uncertain but is probably related to the tectonic thinning of the upper crust above the detachment. The extensional structures are truncated at a major east-west trending fault zone, the Arakapas Fracture Zone, which has been interpreted to be a fossilized transform fault. The domal outcrop of Mount Olympus lies at the intersection of the fracture zone and the center of the Solea graben and may represent an exposure of crust and upper mantle that formed beneath a ridge-transform intersection nodal basin. Slow-spreading mid-ocean ridge-transform intersections show many of the same geometrical relationships at a similar scale as those exposed in the Solea graben portion of the Troodos Ophiolite. The Solea Graben spreading center provides a model for the structure of modern mid-ocean ridges that are spreading amagmatically.