3 May 2012
Big old vesicles!
Posted by Callan Bentley
Today, for your viewing pleasure, I offer you: A series of big honkin’ gas pockets in a 615 ka basaltic lava flow in the Owens Valley of California. This same lava flow has been featured here before, since it imparted a lovely contact metamorphism to the alluvial fan over which it erupted.
These things are weird – they’re all about the same size and the same shape (and the same orientation). They all have these wrinkly bulbous blobs projecting inward. I thought about lava tubes, as I’ve seen similar sized features in Hawaii that were old lava tubes, but these things were not cylindrical — they were round and flat, kind of like a crumpet or a nonpareil.
Anyone want to share some insight on whether these are in fact vesicles, or something else altogether?
maybe some of them are lava casts like those near bend, oregon
What’s a “lava cast”?
as lava flowed thru a forest it flowed around trees. after the lava cooled (and the trees burned) the trees left imprints as hollow cylinders. some of them even have imprints of the tree bark. there’s an easy trail about 15 miles south of bend, oregon that has a lot of them..
Oh – that. I’ve seen those in Hawaii.
No, that’s not what these are – these are 3D lens shapes (like the upper “cap” part of a mushroom), not cylinders.
Thanks for suggesting it, though.