Do structural differences along strike of the Himalaya range represent changes in the pre-collision geometry of Greater India prior to collision?

Over the past few decades understanding of orogen development has evolved at a rapid pace, with classic geologic principles being combined with complex computer aided thermo-mechanical simulations, to produce testable models of orogenic growth1, 2. Typically, Greater India’s pre-collisional northern edge, is usually modeled as a rifted passive margin. However, some workers3 have argued for a quite different geometry resulting from its prior tectonic history. Whilst the western portion of the paleoboundary is seen as a Triassic rifted margin, the central and eastern portions developed more recently as India separated from Australia along a dextral ‘scything’ transform fault. This envisages the central-northern boundary to be a ...postprin