干旱区生态环境知识资源中心

New structural data collected along five transects across the trend of the Feiran-Solaf metamorphic complex (FSC) in the Sinai, provide a more precise depiction of the macroscopic folds. The two main macrofolds of the complex, the NW-SE trending Feiran and Solaf antiforms, appear to be thrust-related folds with detachments at different stratigraphic levels in the FSC. Contrary to earlier views, there is only one macrofolding event (D2) in the FSC, accompanied by NW-SE trending F2 mesofolds with varying style. While the F2 mesofolds are most commonly open concentric and symmetrical, some of these folds have been modified by inhomogeneous shear strain to become tight "similar" style asymmetric mesofolds in a zone of intense ductile shearing along the SW flank of the Feiran antiform. The recent Najd related transpression model for FSC 02 deformation is evaluated. An alternative model for D2 as a product of orthogonal convergence is preferred. The D2 event recorded the collision of the FSC with the Sa’al terrane at -800 Ma. The Kid arc complex collided with the Feiran and Sa’al complexes during subsequent NNW-SSE convergence at about 620-600 Ma. (C) 2017 Elsevier Ltd. All rights reserved.