Hello Young People.
Petrified Wood.
Out hiking today near Vantage, Washington.
In the Ginkgo Petrified Forest State Park.
There's a petrified tree right there.
Still standing!
Fifteen and a half million year old tree.
It's been standing here for that long.
It was petrified underneath a lava flow that
was fifteen and a half million years old.
The lava flow has been taken away by the Ice
Age Floods, and this stubborn tree held its
ground.
When you come out here and look, it's a desert
landscape.
We get less than ten inches of rain a year.
But when these trees were alive, this was
a dense forest.
Studying the kinds of wood that's out here
- the petrified wood - we know we have a variety
of trees that were dominating this area.
Those kinds of forests today only survive
in places that have fifty inches of rain a
year.
I'm talking about the forests of southeast
United States or eastern Asia.
The Ginkgo trees are rare, however.
More than 50 per cent of the trees are either
Douglas Fir or Spruce.
To understand how the petrification process
took place to turn these trees to stone, let's
take a closer look at some of these logs.
We're at the museum at Ginkgo State Park.
Got petrified logs laying on the ground here
for visitors to enjoy.
It's petrified!
These are logs made out of stone!
And they were pulled right out of basalt lava
in the hills.
Logs right in the lava.
Why didn't the logs just burn up from the
heat of the lava?
They survived because there was water present.
The logs were pulled out of the pillow zone
at the base of a lava flow which tells us
that water dominated this landscape.
The lake water protected the logs from the
heat of the lava and there was so much lava
that we sealed off those logs from the atmosphere
so we didn't rot the logs with oxygen.
We had the right ingredients then for petrification
- a lot of water, a lot of heat, and minerals.
Silica, from the overlying basalt lava.
The hot water allowed for transfer of the
silica into the wood.
Soaked into the wood.
And exquisitely preserved the cell structure
of these logs.
We can then identify the different kinds of
wood - the different kinds of trees - based
on the patterns of these cell structures.
Petrified logs.
At Vantage, Washington.
