OntarioHunter
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The rock around it looks like pillow basalt. I suspect it may be a lava tube.
Topo Anomaly
- Thread starter westbranch
- Start date
westbranch
Well-known member
Spring bear was one of the reasons I was looking at the area. By late June should be able to access from easier point on the ridgetop.
44hunter45
Well-known member
I will slow you young bucks down, but I'm game to go up there.
Southern Elk
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This is really interesting. I wish it wasn’t December, so somebody could check it out. I’d be interested to hear what @Nameless Range thinks once he’s had a chance to study it.
J
Jason73
Guest
Volcano tube? Probably not the technical term .
Nameless Range
Well-known member
I don’t think digital sources are going to resolve it and someone’s going to need to hike in there to verify . What a fun mission. If I had to put money on it, it is an error, and is just a pile of rocks or potentially small spire.
I would think a 1400 foot deep hole a few hundred feet wide would be a pretty well-known feature. Those are similar measurements to the Cave of Swallows in Mexico, and that makes me skeptical.
Cave of Swallows - Wikipedia
That said I don’t know. How cool would it be if it were a never-mentioned hole in the ground some guy found looking at maps that never made it onto maps until aerial sources of elevation data picked it up hidden in the rocks and nasty stuff where it was visually obscured from the surveyors of yesteryear.
Fun thing to think about over the winter.
westbranch
Well-known member
Yeah, reading through forest service info on roadless areas it seems like a geological feature like that would be mentioned. Or there would already be a hiking trail to it.
J
Jason73
Guest
Off topic but was gonna catch TOOL on this run of shows....until 3 tix were gonna be about 700 bucks. Bummer. Guess I'll be thankful for the 3 shows I did see. One being on the 2nd stage at Lollapalooza in 93 on their first tour. Special memory for sure. Cheers!
Im seeing them in January, will be my third show since 2020 and I think fifth total
Irrelevant
Well-known member
Hot tip, if you're not a geologist, don't make wild ass guesses at geology from google earth.
It's not a frickin' lava tube.
It's not a frickin' lava tube.
OntarioHunter
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Look at the map. Basalt formations are common in the vicinity of the Clearwater River. If you need some assurance that basalt is a volcanic rock, I suggest you Google the term. And while you're at it Google lava tube. You'll see they are formed in basalt flows. Since the predominate rocks in the mountainous area of the Clearwater are either basalt or "granitic" (also volcanic in origin) it is unlikely this feature is a sinkhole. Those are found in limestone formations which are sedimentary/metamorphic.
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OntarioHunter
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A mine would leave some indication of excavation, i.e. tailings. No sign of a road or trail to the spot. It's almost certainly not man-made.very cool.
I’m in the car and so I can’t look myself, but two things I might do is look at any historical topo‘s that intersect that location. If it appears on maps preceding the 2000s it isn’t a LiDAR return error.
Topo Map Explorer
livingatlas.arcgis.com
Also, Idaho has a cool LiDAR viewer. highly unlikely that any LiDAR has been incorporated into any topo maps or even on x.
Existing Lidar Data – Idaho Lidar Consortium
www.idaholidar.org
I can think of a couple mines that when viewed three dimensionally in onx Or other 3-D viewers, appears similarly to what you’ve shown above. i’ve also seen instances of bridges that appear as depressions.
It would be neat if it was a giant hole
SD_Prairie_Goat
Well-known member
Am I the only one that thinks it's a pile of rocks that got incorrectly mapped as down instead of up? Sure looks like it from the Google earth image, doesn't it?
np307
Well-known member
That's what I thought too. Then I figured enough people were commenting about lava that I was crazy.
D
Deleted member 28227
Guest
Agree, given the old map it looks like what might have happened is when digitizing the lines someone assigned descending values instead of ascending values.
That topo layer was then used to create the DEM, and thus the error was propagated.
Bambistew
Well-known member
Tailings are not an indication of excavation, they are indication of milling ore... What you mean is waste rock piles or dumps.
I'm no geologist, but I highly doubt that is pillow basalt, or a remnant lava tube in a vertical position. Vertical shafts do not stay open that long.
I will put $100 on it, and say there is a spot elevation at that point, either new or historic, and it was somehow changed (as it it was meters, or was read at 2500, instead of 5200). The model was generated and no one caught it. Lidar isn't picking up that level of detail on a what, 25m grid? Just a hunch, going on 20+ years of experience generating terrain models... ones with actual shafts and pits, and using high definition lidar
The weird swirl, is the computers attempt to drape the image on the F-d up terrain model. It stretches the image to match the surface area.
Southern Elk
Well-known member
I agree, from looking at that satellite photo, it looks like some sort of rock formation.I don’t think digital sources are going to resolve it and someone’s going to need to hike in there to verify . What a fun mission. If I had to put money on it, it is an error, and is just a pile of rocks or potentially small spire.
I would think a 1400 foot deep hole a few hundred feet wide would be a pretty well-known feature. Those are similar measurements to the Cave of Swallows in Mexico, and that makes me skeptical.
Cave of Swallows - Wikipedia
en.m.wikipedia.org
That said I don’t know. How cool would it be if it were a never-mentioned hole in the ground some guy found looking at maps that never made it onto maps until aerial sources of elevation data picked it up hidden in the rocks and nasty stuff where it was visually obscured from the surveyors of yesteryear.
Fun thing to think about over the winter.
westbranch
Well-known member
I have definitely been leaning towards some sort of mapping error from the beginning. The error is likely compounded in some way, there is no way its a 1k+ tall pillar. Just like if it was a big hole there would be pictures of it online and hiking trails to that spot already. Probably a rock formation no more than 150-200 ft above the surrounding rock.
I am still thinking I should hike in there next June and see if there are bears around. We'll see if ends up being a HTrs of North Idaho trip.
