Scientists have found ancient rock formations dating to the late proterozoic eon in south america. these ancient rocks can be found from the eastern edge of south america's continental shelf, which extends just off the coast of brazil, to the interior of the continent. this general location is indicated by a green circle on the map below. scientists have also found rock formations made out of the same type of rock and from the very same eon at another location. the location of this second group of rock formations strongly supports the current theory of plate tectonics. where is the second rock formation most likely located?