Very smooth plains material flanks some scarps and ridges and, if the material is ponded extrusives or mass-wasted products, may postdate the structures.
For hominins, the isotopic evidence for dietary expansion postdates the beginning of major morphological dentognathic changes among australopiths and, as such, it represents a subsequent phase of increasing dietary breadth.
The highly degraded nature of c1 craters makes it impossible to determine whether the craters predate, postdate, or are contemporaneous with the intercrater plains unit.