By the Quaternary Period, the landmasses had achieved the basic shapes and global positions in which we see them today. Click here to see an animated image of the Atlantic Ocean forming. Pleistocene Epoch Rocks of Nova Scotia Core samples of deep ocean sediments provide evidence that there were more than 16 glaciations during the Quaternary Period, starting at the beginning of the Pleistocene Epoch. There was a marked transition from glaciers to renewed warmth. Each major glacial advance, by its nature, tended to destroy evidence of previous glaciations.
Oceanic sediments contain the only clues to earlier glaciations.
If not for samples of oceanic sediments, this part of Nova Scotia's geological history would remain a mystery. The interval between the Illinoian Glaciation and Wisconsin Glaciation is called the Sangamon Interglacial. It is represented by marine and terrestrial deposits that underlay the till of the Wisconsin glacial period. This higher sea level cut a new shoreline and left behind flat wave-cut rock benches that were later covered by glacial deposits. A wave-cut platform rings Cape Breton and is also exposed on the western shore of mainland Nova Scotia.