Fig. 2 - The Trishear model explains forelimb deformation - in general terms - as represented by fault arras in these areas for example. But how is strain localised into the forelimb? Is there a simple predictable pattern? Is it consistent along a particular structure? This issue is important for making fracture predictions in compression structures on the basis of large scale geometry. Aim here is to explore evolution of a fold-thrust complex - using syn-tectonic sediments.