Four stages mark development of chevron folds: sinusoidal nucleation, concentric folding, straightening of limbs/sharpening of hinges, and tightening of the chevron fold. When inter-limb angles approach 60 degrees, frictional forces limit simple shear and flow deformation in less competent layers and favors pure shear of the whole stratigraphic complex. Therefore, the inter-limb angle, rapidly decreasing as a function of time given larger angles begins to stabilize as the angle nears 60 degrees. There is, however, no physical limitation on the acuteness of the fold.