Metamorphic rock is the result of the transformation of a pre-existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and ...

Figure 1: The eastern Papuan peninsula has been undergoing extension since at least 6 Myr ago. Figure 2: Schematic interpretation of the present-day crustal structure along the heat-flow profile ...