Orogeny in the Precambrian

As we have seen in the previous chapter, it becomes progressively more difficult to interpret the structure of orogenic belts as we look further back in time, beyond the period when accurate continental reconstructions can be made from oceanic palaeomagnetic data. This difficulty is magnified in the Precambrian because of the inherent inaccuracies of continental palaeomagnetic reconstructions, and is compounded by other problems. The familiar stratigraphic certainties conveyed by accurate palaeontological dating in the Phanerozoic are absent throughout much of the Precambrian. The widely-used radiometric dating methods cannot yet give the same precision in subdividing and correlating stratigraphic sequences.