This example shows the computed deformation field of a thin viscous sheet, on which a segment of the southern boundary (shown here in conventional map view) is slowly indented to represent the northward movement of India relative to the rest of Asia during the past 50 Myr.  The arcuate segment of the southern boundary in this case represents the arc of the Himalayan mountain chain.  India (not shown) is assumed to be a rigid indenter.  As India moves northward into Central Asia, shown by the displacement of the boundary in the lower-left diagram, the crust and lithosphere of that region is pushed out of the way, and primarily responds by thickening.  The colours and contours in the top left diagram illustrate the variable extent of crustal thickening, which reaches about 70 km across the Tibetan Plateau (just north of the Himalayas) and about 55 km in the Tian Shan Range that forms to the north of the Tarim Basin block.

    In this experiment thickening of the crust is not resisted by gravity acting on the buoyancy of the low density crust, and there are still significant eastward displacements on the eastern boundary which is permitted to move outward.  The largest vertical strain rates (shown in the upper right diagram) occur on those regions of maximum crustal thickness.

Relevant Publications

Houseman, G.A., and P. England, Finite strain calculations of continental deformation 1. Method and general results for convergent zones, J. Geophys. Res., 91, 3651-3663, 1986.

England, P., and G. Houseman, Finite strain calculations of continental deformation 1. Method and general results for convergent zones, J. Geophys. Res., 91, 3664-3676, 1986.

Houseman, G., and P. England, A lithospheric thickening model for the Indo-Asian collision, in A. Yin, and M. Harrison (Eds.), The tectonic Evolution of Asia, Cambridge University Press, pp3-17, 1996.

Neil, E.A., and G.A. Houseman, Geodynamics of the Tarim Basin and the Tian Shan in central Asia, Tectonics, 16, 571-584, 1997.