Complex sentence: Chan-Chan is known to have been inhabited by hunter-gatherers during two periods of the Middle Archaic separated by a hiatus, one of them spanning from 6250-6420 BP and the other 5730-6130 BP.
Split into simpler sentences: Chan-Chan is known to have been inhabited by hunter-gatherers during two periods of the Middle Archaic, separated by a hiatus. One period spans from 6250-6420 BP and the other from 5730-6130 BP.