History of the Earth
The geologic record of the Proterozoic is much better than that for the preceding Archaean.  In contrast to the deep-water deposits of the Archean, the Proterozoic features many strata that were laid down in extensive, shallow epicontinental seas; furthermore, many of these rocks are less metamorphosed than Archean-age ones, and plenty are in fact unaltered.p315 Study of these rocks show that the eon featured rapid continental accretion (unique to the Proterozoic), supercontinent cycles, and mountain-building (orogeny) activity.p315/8; 329/32