Ice Age Glacial Lake Missoula Flood Erratic Boulder ID'd--near Salem, Oregon
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- čas přidán 19. 12. 2022
- This video features the Bellevue Erratic--the largest Ice Age flood boulder in Oregon's Willamette valley--originating from the glacial Lake Missoula area, Montana. This Missoula Flood boulder is located at Erratic Rock State Natural Site, near Salem, Oregon. This rock is an argillite from the Rocky Mountains (from the general western Montana, northern Idaho or British Columbia areas). This video uses 360 degree photography.
Glacial erratics are rocks of any size (although the term often is applied to large boulders). These erratics have been transported by a glacial ice sheet or a glacial iceberg--to a locality far from the area where the rock originates. This means that the rock type associated with the glacial erratic does not match the rocks in the area to where it was deposited. Although an erratic could be any rock type, most erratics are highly competent rocks (such as an igneous or metamorphic rock). Such competent rocks can resist intense abrasion, weathering, and distant travel (generally associated with a glacier).
This specific boulder is special. It travelled 500 miles in an iceberg, when the Glacial Lake Missoula drained in a massive flood in just 48 hours. Glacial Lake Missoula was a "Great Lake-sized lake" during the last Ice Age. A glacial ice sheet from Canada, moved southward into northern Idaho and western Montana. Then the ice sheet blocked the Clark Fork River, to create a great ice dam across the valley.
Glacial Lake Missoula progressively filled with water up to 2,000 feet deep. However, ice does not make a competent ice dam. Ice can both melt in water and float in water. Additionally, glacial ice often contains various weak areas--such as from fractures within the ice sheet. Eventually, the deep water within the glacial lake, surmounted the strength of the glacial ice dam.
This created an immense flood that flowed to the Pacific Ocean through both Washington and Oregon. The great Missoula Flood carved huge valleys and eroded fertile soils from the landscape. The flood also carried many icebergs from the area--where the glacial ice dam disintigrated. These icebergs carried rocks and boulders from as far away as British Columbia. These ice-rafted boulder were scattered in many areas of Washington and Oregon. In the Willamette valley south of Portland, some of these erratics were deposited as far away as Eugene, Oregon.
This huge glacial erratic provides evidence of the immense power of the Ice Age Missoula Floods--at a location so far from its origin. This small country park is often overlooked, and has an amazing story to tell. Multiple Missoula Flood events occurred at the end of the last Ice Age. After the significance of the Missoula Floods were recognized, other locations on Earth showing great flood events were recognized. Additionally, similar flood event features have been found on the surface of Mars. For this reason, the Mars Rover spacecraft were tested in the Missoula Flood areas in Washington State, before being sent to Mars! Amazing!
For more information and directions, this link connects to the Oregon State Parks website for this location: stateparks.oregon.gov/index.c...
Hello Rock People! This is Dave the Geology Dude. Please be aware that the only way to really learn rock identification, is to have hands-on experience. This is because visual experiences alone do not show properties like hardness, acid reactivity, density, and the range of variables that are common to each rock type. Don't forget that Geology isn't Rocket Science--it's Rock Science! Please "like" and subscribe to this CZcams channel!
Music (CZcams Audio Library): Wandering Soul (by Asher Fuller). Erratic Rock State Natural Site location map provided by Google Maps (©2022). Missoula Flood map (Topinka, 2002) provided by U.S. Geological Survey/Cascade Volcano Observatory [public domain link: www.usgs.gov/media/images/pac...]
Copyright by David Knoblach, 2022. All rights reserved
I bet that giant boulder was so happy to finally get off that mountain and settle in the valley. All his buddies are still waiting for their glacier to come in!
Ha ha!
It must be a really big iceberg!
Yes it had to be enormous-especially to last for such a long distance!
Wow this video is doing well, look at those views!
Yes, this was a good one! Thanks much Jason! Great to hear from you!
Nice rock never seen on that size float 😆 500 miles
Yes (ha ha), but ice helps to float it-if there’s a lot of it! It’s an incredible story for a fairly ordinary rock! Thx for your comment!
Jack Frost got some muscles 💪🏼
@@mafic_taco7061 ha ha!
Hello Rock People! This is Dave the Geology Dude! There is more to this video than just a spinning rock. There are detailed notes in the description area of this video. Please check out the many rock identification videos on my CZcams homepage too, or leave a comment here!