| Niagara Falls continued |
| The rocks that are in the Niagara falls (talice, bedrock, etc) consist of different groups. They're all Early Silurian except for the bottom layer, which is Late Ordovician. The information below will show the data: Lockport (75 ft thick~23 m) mined for crushed stone and concrete aggregate deposited when shallow sea covered area. Fossil, plants, and coral reefs are common Lockport Formation, Decew Dolostone, Rochester Shale, Irondequiot Limestone, Neahga Shale Clinton (115 ft thick~35 m) covered by water, then land, then water again. Changing climate and landscape beacause of this difference in covering. Many various fossils also found. Thorold Sandstone, Grimbsy Formation, Power Glen Shale, Whirlpool Sandstone Medina (125 ft thick~38 m) erosion occured ~ reds, greens, and pinks found in the rock, but few fossils found. Queenston Shale (112 ft thick~36 m) uncomformity resulted in extensive study of the top as there was missing geologic information. Late Ordovician Queenston Shale |
| Rock Beneath Niagara |
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| How and When the Falls Formed |
| The Niagara area was covered by seawater during most of the Silurian period. The advance of the sea was due to gradual sinking of the land. Deposits from the Salina division and the Medina division are found. Niagara Falls was formed 12,500 years ago. 450 million years ago, the area was beneath ancient seas. For years, debris was deposited on the ocean floor. When the seas retreated, the surface of the new land was a flat plain. Due to forces deep within the earth, the land tilted little by little. From rainwater, streamland rivers formed and the rocks eroded. Soon the land tilted more, forming valleys and gorges (Niagara). Then 2 million years ago, the area was covered by a blanket of ice. Glaciers formed, slightly melted, and refroze, rearranging the lands. About 18,000 years ago, the earth climate warmed, and the retreating ice sheets rearranged the land shapes. As the ice withdrew, the land, released from its pressure of the ice, rose up. The waters spilled from the Queenston site and fell to become Niagara Falls, seven miles from its present position. |