Have you stopped at Vantage’s Ginkgo State Park lately, the location of petrified logs of many species of ancient trees?
It is one of this region’s unique parks, was developed by the CCC’s in the l930’s after Prof. George Beck of Central Washington University had located the petrified forest.
A new video by Prof. Nick Zentner, CWU geologist, has brought us the latest explanation of their origin.
There were three separate petrified episodes, the oldest being the Ginkgo forest at 15.5 million years.
Petrified logs are found south of Vantage at many places all the way to the Columbia River site near Roosevelt. It was the basalt floods that made the petrified logs, logs that were in lakes at that time.
The logs, Zentner said, came in debris flows, ending in sediment beds at the foot of the basalt, protected by the water from burning up. The heat of the lava allowed the silica to invade the logs, replacing their wood with stone over time. The landscape has changed since then, as plate tectonics have squeezed this part of the region, with the result of finding petrified logs at many elevated locations.
What was originally flat ground has been twisted into today’s landscape.