The major features of the landscape of Nova Scotia are all the product of its long geological history. The minor features, such as the final rounding of surface features, the alignment of surface lineations, surficial deposits and sea level changes, are the product of glacial activity during the Quaternary Period.

The Quaternary Period can be divided into two time frames. The Early Quaternary is known as the Pleistocene Epoch and stretches from 3 mya until 10,000 years ago. From 10,000 years ago to the present is considered Recent.

Global View - Were was Nova Scotia?

By the Quaternary Period, the landmasses had achieved the basic shapes and global positions in which we see them today. Nova Scotia was (and still is) located on the eastern coast of the North American continent at the edge of the ever-widening Atlantic Ocean.

Click here to see an animated image of the Atlantic Ocean forming. (127k)

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. Each glaciation lasted about 100,000 years, progressing slowly and hesitantly from a warm interval (called an interglacial period) to colder and colder conditions, until huge ice sheets covered most of Canada. There was a marked transition from glaciers to renewed warmth. The present relatively warm, ice-free period may mark the end of the last ice age, or it could be an interglacial or even an interstadial interval (a pause before the next advance).

Each major glacial advance, by its nature, tended to destroy evidence of previous glaciations. In Nova Scotia, only the last two glaciations (called the Illinoian and Wisconsin) have been identified. 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. During this time sea level was about five metres (16 feet) higher than it is today. 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.

The Wisconsin Glaciation began about 75,000 years ago. The main events have been interpreted from the deposits resting on top of the marine platform and from striation patterns which indicate ice flow direction. The Wisconsin ice sheet was responsible for most of the till deposits and erosional features seen in Nova Scotia today. At its maximum, the ice extended out across the Scotian Shelf.

As the worldwide continental ice sheets melted, sea level rose and water returned to the Bay of Fundy and Gulf of St. Lawrence. Small masses of ice remained on the higher areas of the province and the Annapolis Valley was still choked with ice 14,000 years ago. Meltwater deposited sediment in the form of kames, eskers, outwash plains and deltas, especially in the Annapolis Valley and along the north shore of the Minas Basin. The land rebounded as the heavy ice melted and the post-glacial deltas and beaches were lifted as much as 30 m (98 ft) above sea level in the Bay of Fundy region.

By 12,000 years ago, the last of the ice had virtually disappeared. Evidence of an early campsite in the Debert area, west of Truro, indicates nomadic people hunted here 10,600 years ago. Sea level began and continues to rise, submerging much of the coastal area of Nova Scotia and producing the deep inlets and harbours that are valuable for fishing and port development today.

Pleistocene Paleoenvironment

During the Sangamon Interglacial, sea level was higher than it is today. Shelly marine sand in cliff sections in southwest and northern Nova Scotia indicate familiar marine conditions. On dry land, plant and animal life was also essentially the same as present day, with the addition of a few more large animals such as mastodons.

Plants and animals were displaced by the ice, migrating to warmer areas as the ice sheets advanced. Some plants, however, survived in glacial refuges along with the hardy mastodons which lived in Nova Scotia at this time. During the Wisconsin Glaciation, sea level was at its lowest - 80 m (262 ft) below the present level. The coast of Nova Scotia experienced polar sea conditions, with water temperatures hovering near the freezing mark.

Recent

Rocks of Nova Scotia

The discontinuation of glacial evidence in the landscape signals the end of Wisconsin Glaciation (and the Pleistocene Epoch) approximately 10,000 years ago. During the latest phase of geological development on the Scotian Shelf, sediment banks were built out along the edge of the continental shelf. The final veneer of glacial deposits, including moraines, was deposited as the Wisconsin ice sheet retreated.

Paleoenvironment

Temperatures rose at the end of the Wisconsin Glaciation, and Nova Scotia entered a warm period. There was a fluctuating but general rise in sea level as the ice sheets melted, flooding areas such as the Bedford Basin. The coastal waters neared today’s conditions and what we now consider normal temperature (4-10 degrees Celsius).

Animals returned to the province, following the retreating ice, and familiar plants recolonised the land. Eventually, forests developed. The environment proved suitable for human settlement, the first evidence of which has been found at Debert. The archaeological history of Nova Scotia had begun.