The ocean floor provides an ideal location to explore Earth history because deep-sea sediment and rock layers are generally much more continuous and less disturbed than comparable formations on continents, which are exposed to the erosional forces of wind, precipitation, rivers, and sea level fluctuations. The ODP has recovered sediments ranging in age from the last decade all the way back to the Triassic Period, nearly 227 million years ago.
Time scale adapted from "a Phanerozoic Time Scale" by F.M. Gradstein and J.G. Ogg, Episodes, vol 19, no's 1 & 2, 1996