The geology of Lassen Volcanic National Park is widely varied and yet the same. It ranges from hard separate rocks to basalt to crumbly ashy deposits. It's the same because it is all the result of volcanic activity.
I am not a geologist, not even amateur. I am just a curious person that notices differences and attempts to explain them to myself.
Almost centered in this frame is a volcanic cone. The shape gives it away and the forest on it means it is not particularly new. There are several of these easily identifiable cones in the park.
Here is a detail of a rock we looked at earlier in this series. This is obviously a volcanic rock and equally obviously very sulfur based. I photographed this rock in the first 15 minutes in the park.
This looks like it ought to be loose and crumbly, basically held together with mud. It is not, it's solid as can be and what looks like 'filing' is just smoother rock. I'm sure it is related to the previous photo but with different contents in the mixture.
Another detail of some of the 'crumbly mud' looking rock. You can plainly see other rocks that were embedded in this deposit.
Here is a peak made largely out of an ashy ejection. You can tell by the color and the deep canyons left center that it is loose and fairly easy to erode. In the very right center is a very solid basalt peak.
There are also areas of polished and scoured bare rock in the park. It's too far south to have had the ice sheet from the last ice age, but there have been many large and active glaciers in the park in the not too distant park.
As if all those types of rock formed here were not enough there is this gizmo. It's a highly precision GPS unit that is able to monitor the spot it's on to within less than an inch.
The station and the system monitors the movement of the tectonic plates in the region, the rise and fall that are part of volcanic activity and earthquakes in the area.
The mountains in the park were formerly much larger but all of the forces of nature keep grinding them down. First are broken stacks of rock. These were probably piled by a glacier.
What you see here is crumbled up mountain just before it is realized as dirt and silt that make it possible for the trees to grow.
My last photo from Lassen Volcanic National Park is a basalt ridge. They are quite common throughout the park, and a good place to finish this series.
It's been really fun for me to see and to share. I hope you have enjoyed it half as much as I have. Thanks for hanging with me for the whole thing.
All words and photographs in this post are mine. For better or worse.
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