Link to Owner Dr. Robert B. Pamplin Jr.



The 15,000-year-old boulder was discovered during construction at Lakeridge Middle School.

PMG PHOTO: JONATHAN HOUSE - Lakeridge Middle School students check out a 15,000-year-old rhyolite boulder unearthed on the school's grounds.Lakeridge Middle School students gathered at the construction site adjacent to the school Monday, May 17 for a geology lesson. This unusual setting for LMS science classes was due to an unexpected find during the excavation of the old Lakeridge Middle School building.

The Skanska construction crew found a 15,000-year-old boulder, along with hundreds of other more common boulders, while excavating the old school site.

Jacob Parker, the Skanska employee who found the rock, said they were initially concerned it was radioactive.

"While excavating out the school we found probably 400-500 large boulders … and that was one different boulder than all the rest," he said.

He used a rock identifying app to try to identify the boulder. The app suggested it was a radioactive rock, which prompted Skanska to contact a professional to identify the strange relic.PMG PHOTO: JONATHAN HOUSE - Lakeridge Middle School student Spencer Walkenhorst shows off a piece of a 15,000-year-old rhyolite boulder unearthed on the school's grounds.

Scott Burns, Portland State University geology professor and president of the Tualatin Ice Age Tourism Foundation, identified it as a rhyolite — an ice-rafted erratic that most likely made its way to the site during the Missoula Floods, the geological event that led to the creation of the Willamette Valley.

The boulder measured 3 feet long, 3 feet wide and 2 feet high, weighing in at a surprising 2,000 pounds.

To everyone's relief, this rock is not radioactive. But it is special. Burns said that of the hundreds of boulders brought to the Willamette Valley by the Missoula Floods, this boulder is only the second rhyolite to be found.

"It's just rare on this side of the mountain," Burns said. PMG PHOTO: JONATHAN HOUSE - Geology professor Dr. Scott Burns gives a short presentation about a 15,000-year-old rhyolite boulder unearthed on the school's grounds.

Burns gave an outdoor presentation about the boulder at the construction site. Students were able to ask questions and touch the rock.

Eighth grader Amber Ybarra said she was excited when her teacher told her the class would be viewing a rock during class.

"I love rocks and think they are pretty. This rock is so cool," she said.

Principal Kurt Schultz said the LMS students in LO Online were able to access the presentation virtually.

That afternoon, the boulder was donated by the district to the Tualatin Heritage Center, where it will be available for public viewing along with the other erratics at the Tualatin Ice Age Tourism Foundation. PMG PHOTO: JONATHAN HOUSE - Skanska Senior Site Superintendent Jacob Parker oversees the moving of the boulder unearthed at Lakeridge Middle School. The rock is now on display at the Tualatin Heritage Center.PMG PHOTO: JONATHAN HOUSE - The boulder is moved onto a truck that was taking it to the Tualatin Heritage Center.

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