GEOLOGIST ACTIVITY BADGE

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WHERE TO GO; WHAT TO DO

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CARBON MINERALS

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METALS/ORE

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MOUNTAINS

Here are some sample questions to get your discussion underway

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HOT GEOLOGIC HISTORY

Almost all geology in north west Oregon is pretty recent - less than 50 million years old. These stories are based on information gleaned from the Roadside Geology of Oregon, Alt & Hyndman. A valuable resource.

Geology.com lists all the Roadside Geology books available. These are great resource books for thee Geology Activity Badge for your area.

MASSIVE FLOOD HELPS AREA FARMERS

In recent geologic times (some 10-15 thousand years ago) as the Ice Age was ending, a huge tongue of a glacier created a dam and formed Lake Missoula covering much of present-day Montana.

As the glacier receded, the ice dam broke, sending the the entire lake crashing down into the Columbia valley. It carried earth, trees, even huge boulders - the size of large buildings - along with it. This happened as many as thirty times as the ice-age glaciers advanced and retreated.

As the flood reached the Portland area, the debris jammed up the outlet between the West Hills and the hills near Long View. The onrushing flood was diverted west to the coast range and south as far as Eugene.

One of the huge boulders can be seen at Erratic Rock State Park, just off Pacific Highway between McMinnville and Sheridan. Geologists tell us that this Rock - the size of a house - was carried by the flood from near the Idaho Montana border.

The silt from this and similar floods gives the Willamette Valley its fertile soil. Contrast this with the valley between Long View and Olympia, that has much poorer soil.

Weather

HOT HUMID SPELL ENDS

Some 15 - 25 million years ago, Oregon had a hot, wet, tropical climate. Tropical vegetation causes the soil to retain iron oxides, giving it a distinctive red color.

During this era, aluminum rich bauxite laterite soil was being laid down throughout our region. The iron oxide impurities make it unsuitable for present day aluminum production.

The red soil can be seen along Rte. 26 near Buxton, and forms soil of the famous Redlands near Newberg and Dundee.

VOLCANIC ISLAND CRASHES INTO COAST

Cape Lookout, just north of Webelos Camp at Adventure Cove, Camp Clark was once a volcanic island. Its origin is similar to that of Hawaii. Webelos going to camp there should look for the basalt lava flows that formed the cape. You may see examples of pillow lava that formed under water if you look carefully at the base of the cliffs.

Actually, the North American tectonic plate crashed into the islands as it drifted westward rather than the other way ‘round.

These volcanic capes along the coast are the source of the agates found along the Oregon beaches. Agates are formed by ground water seeping through the porous volcanic rock. The water deposits quartz that gradually fills the cavities in the basalt. As the pounding waves erode the basalt, the agates and zeolites are carried away and storms wash them up on shore as pebbles. ( Flint - or more properly: Chert, is formed in a similar manner as water seeps though limestone or chalk deposits. )

Cape Kiwanda, just south of Camp Clark, is not volcanic but is comprised of sandstone and mudstone formed on the ocean floor.

TRIMET BORES THROUGH LOCAL VOLCANO

The extinct volcano that forms Mount Sylvan is best seen from the inside. Webelos should take the Max train to the Zoo station and examine the drill core on display there.

This is a rather recent volcano, about 3 - 5 million years old active during the Pliocene. Its lava flows cover the silts and bauxites that developed during Miocene time.

There's a good display of the tunnel at OMSI.

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