The history of the Falls began about 600 million years ago. In this era a broad shallow sea covered most of North america. Under the water already the rocks of the former canadian shield were present. During about 100 million years passing along soft sediments were deposited over the Pre-Cambrian rocks. After the Appalachian mountains were formed rivers flew in new patterns carriying mud westward which cemented by eons forms the Niagara Gorge. |
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About 300 million years ago the inland see drained away and the sediments layed about 5 km high above the Pre-Cambrian rocks. Fifty million years later great rivers flew all over the continent forming randomly patterns into the sediments. These patterns formed later on the basins of Lakes Huron and Michigan and later Erie and Ontario. |
(Source: http://www.ee.cityu.edu.hk/~gchen last reviewed on: August 19, 2004) |
Since the time when the glaciers started to retreat about 12000 years ago the Niagara Falls moved from about 11 km down the river to their actual location by erosive destruction of the ground. Also nowadays the Falls move up to 1 m per year against the rivers direction. Some scientists claim that the Falls will completely disappaer after a certain time even while the erosion seems to be much slower than in former times. |