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  • Essay / Kamiak Butte Test - 931

    Here the ground was compressed under extreme pressure at a convergent boundary, resulting in upward movement to create the Cascade Mountain Range.1 Next , lava poured out of fissures in the earth's surface, covering most of the landscape while leaving the mounds uncovered.1 This formed basalt that was 6 to 17 million years old. Better known as the Columbia River Basalt Flows, this basalt flow covers nearly 200,000 square miles in Washington, Idaho, and Oregon. It can be several hundred feet thick.1 At the end of the last ice age, wind-blown silt covered the lava and basalt deposits. This silt would go on to create the fertile hills of the Palouse. This soil is in places more than a hundred feet deep. Soon enough time passed for vegetation to take place and more soil to begin to form.1 Lava flows would eventually block the streams flowing from the mountains; in turn forming the current lakes of the region. Between the basalt flows are deposits of sand and gravel that have been carried away by the waters.