Fossil and Erratic Sites Discovered on Our Annual Picnic

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Fossil and Erratic Sites Discovered on Our Annual Picnic
  1. Tualatin Library – Mastodon mounted bones, NARG tusk, Woodburn and other fossils located inside. 
  2. Tualatin River Greenway Path – The ¾ mile newly completed trail exhibits casts of fossils, erratic rocks, and each step represents 25 years of geologic time. 
  3. Heritage Center – Showing 10 and 2.5 ton flood erratics in front. A group of Tualatin’s erratic rocks and other fossils are also displayed inside. The center is open M-F 10-2. 
  4. Mastodon Bronze Sculpture – and small bronze boy outside the SW corner of Cabela’s. 
  5. Cabela’s – Fossil casts are located inside sporting goods store, at the entrance and center back. 
  6. Mastodon discovery site – Located near the southwest edge of the Fred Meyer parking lot in blackberries, next to Nyberg Creek. Discovered in 1962. 
  7. Sweek Pond – Short optional art walk. 
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Radon in the Willamette Valley: An Unexpected Hazard

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Radon in the Willamette Valley: An Unexpected Hazard

At the end of the last ice age 18,000 to 15,000 years ago massive hydrologic floods ran down the Columbia River Gorge.  Originating from a huge glacial lake near Missoula, Montanta around forty floods were large enough to flood the entire Willamette Valley to a depth of 400 ft.  These floods did not just bring huge volumes of water, they brought huge amounts of rocks and sediments from the continental batholiths.  A large percentage of these rocks and sediments are composed of granite.  Granites from the Idaho batholith are high in uranium bearing minerals.  This high uranium content brings with it an unexpected hazard, radon.

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