THE FOSSIL RIDGE-TRANSFORM INTERSECTION (RTI) IN THE TROODOS OPHIOLITE: AXIS CURVATURE AND OUTSIDE-CORNER CORE COMPLEX

The 'missing link' in the comprehensive view of the RTI frozen in Troodos is the extinct spreading axis within the plutonic complex. Measurements of AMS (anisotropy of magnetic susceptibility) from the gabbro suite trace the extinct spreading axis between the Solea graben and the Arakapas fossil transform. The identification of this NW-SE trending axis is corroborated by the parallelism with other markers of axial deformation, such as flow fabric within the mantle rocks, adjacent dikes, and major normal faults. The inference of the extinct axis within the gabbro suite reveals a curvature of the spreading axis eastward with approach to the Arakapas transform, in agreement with the dextral slip and diffused shear north of the transform. This novel scheme of the fossil RTI and the sense of asymmetric extension during seafloor spreading previously found at the Solea graben also imply an early development of outside-corner core complex; the major fault, juxtaposing gabbro and serpentinite, is located off-axis and parallel to the AMS-inferred axis in the gabbro suite.