Petrified Wood - Virgin Valley, Nevada

[Natalie]

I found this interesting piece of petrified wood when I was mining for opal last year at the Royal Peacock Opal Mine in the Virgin Valley region of Nevada. It is very different from the other petrified wood I found... It has a very "airy" texture and even floats on water for a couple minutes before it gets saturated. It almost looks to me like something that would have come from a cactus. Can anyone tell me what type of plant this is from?

I tried looking up geologic maps of the region but I can't really tell anything from them other than that the rock in the areas is volcanic. I think when I was up there I remember the people saying the opal wasn't very old either, I think less than 30 million years (not exactly sure, I think someone here will know the area better than I do). Thanks in advance for any help!

[Auspex]

...It has a very "airy" texture and even floats on water for a couple minutes before it gets saturated.I tried looking up geologic maps of the region but I can't really tell anything from them other than that the rock in the areas is volcanic....

Right there are your two big clues: it's pumice.

[Natalie]

Thanks for the quick reply! That was a possibility I was thinking about, but I guess since it has a "grain" I thought it looked more like wood than pumice. Oh well, I still have many other pieces of petrified wood from that trip that I'm certain are indeed wood.

Since I already made this thread, I have another piece of petrified wood (I think) that I've been wondering about. I found this rock half-buried in the Marin Headlands here in the Bay Area... The specific location is called Hawk Hill if that's any help. The entire "fossil" was probably about 8" long, but it was broken into several pieces and I only took this one piece and left the rest there. I always figured it was some kind of fossilized stick/branch, but there are some things that seemingly conflict with that idea. First, there doesn't really appear to be any sort of organized grain in the specimen. If it is petrified wood, I don't know what part of the tree it would be from. Second, I'd always heard that the rocks in this area were extremely old (on the order of hundreds of millions of years) and were from a sea floor, not a forest. I don't have any maps to back that claim up, but that's just always been what I've heard about the area growing up around there.

So what does everyone think about this one? Thanks!

[Auspex]

The form and structure look consistent with root-wood (think of the gnarly pieces of driftwood you've seen), so if it's wood, it could be that. The only other thing that comes to mind is coprolite, but an 8" one would be a pretty major "dump".

[barefootgirl]

When I was a child living in New Mexico, we would find what we called floating rocks. They were grayish white and when thrown in the water would float. I still have a small one tucked away somewhere.

[MikeD]

There is petrified wood that looks similar to your first post. It was partially rotted before becoming petrified, but it is still relatively heavy and will not float.

[Natalie]

Thanks for the replies! The rock in my first post is very lightweight, so I agree it is just pumice. Petrified rotted wood must look pretty interesting, though. The root-wood theory for the second rock also sounds plausible.

[lordpiney]

Thanks for the quick reply! That was a possibility I was thinking about, but I guess since it has a "grain" I thought it looked more like wood than pumice. Oh well, I still have many other pieces of petrified wood from that trip that I'm certain are indeed wood.

Since I already made this thread, I have another piece of petrified wood (I think) that I've been wondering about. I found this rock half-buried in the Marin Headlands here in the Bay Area... The specific location is called Hawk Hill if that's any help. The entire "fossil" was probably about 8" long, but it was broken into several pieces and I only took this one piece and left the rest there. I always figured it was some kind of fossilized stick/branch, but there are some things that seemingly conflict with that idea. First, there doesn't really appear to be any sort of organized grain in the specimen. If it is petrified wood, I don't know what part of the tree it would be from. Second, I'd always heard that the rocks in this area were extremely old (on the order of hundreds of millions of years) and were from a sea floor, not a forest. I don't have any maps to back that claim up, but that's just always been what I've heard about the area growing up around there.

So what does everyone think about this one? Thanks!

in my opinion..that looks like a piece of putty or window glazing, or something similiar, that hardened like rock.

also, from what ive heard, the whole opal area of virgin valley was once part of a huge forest fire. thats where your pumice came from.

beautiful rosy boa too!