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Express Tour - Section IFire & Ice Set the Stage for Ice Age Floods
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BEFORE THE ICE-AGE FLOODS CAME...THE LAVA FLOWED | |
| About 17 million years ago floods of lava began coating the Columbia Basin of Washington--as well as northeast Oregon, and the Columbia Gorge region all the way to the Pacific Coast. Originating from hundreds of lengthy fissures in northeast Oregon, as many as 300 separate floods deposited thick lava beds over 60,000 square miles. The lava outbreaks ceased about 6 million years ago. Each lava flood cooled and hardened into dark basalt rock which accumulated to a mile in depth throughout much of the region. |
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GLOBAL COOLING THEN BRINGS AN ONSLAUGHT OF ICE-AGE GLACIERS | |
Between 2 million and 2.5 million years ago a combination of cooler temperatures and increased precipitation formed massive ice sheets which repeatedly advanced and retreated as climate conditions fluctuated. Ice coated the Puget Sound lowlands, and most of the mountain regions of northern Washington, Idaho and Montana. So much glacial ice existed that the oceans were 300 feet lower than they are today. The final episode was the Wisconsin glaciation, a cycle that took place from 100,000 years ago until about 10,000 years ago. |
Ice Age Floods Express Tour: Continue | ||||