How does orogenic crust deform? Evidence of crustal-scale competent behaviour within the partially molten middle crust during orogenic compression

Granitic partial melts are generally thought to significantly weaken the orogenic crust and, ultimately, lead to the collapse of an orogen. Studies from different orogens have shown that the syn-melt deformation behaviour at the orogenic scale is, however, more complex. In addition, once fully crystalline, granitic material strengthens the crust. Linking the evolution from melt-present to melt-absent deformation at the scale of the orogen is a...