3162: Heart Mountain

Explain xkcd: It's 'cause you're dumb.
Revision as of 16:52, 4 November 2025 by 216.221.83.168 (talk) (Explanation: Adjusted for better organization of ideas and connection to the comic.)
Jump to: navigation, search
Heart Mountain
Even geology papers about Heart Mountain are like, "Look, we all agree this 'volcanic gas earthquake hovercraft' thing seems like it can't possibly be right, but..."
Title text: Even geology papers about Heart Mountain are like, "Look, we all agree this 'volcanic gas earthquake hovercraft' thing seems like it can't possibly be right, but..."

Explanation

Ambox warning blue construction.svg This is one of 52 incomplete explanations:
This page was created by a GIANT SLIDING ROBOT. Don't remove this notice too soon. If you can fix this issue, edit the page!

The structure of the geology of Heart Mountain, in Wyoming, is a geological anomaly whose current best scientific explanation is highly unusual.

The main anomaly is that the rock at the top of the mountain is far older than that of its base. There are other processes that can result in such inverted stratigraphy, but in this case the evidence does indeed seem to suggest that a (more than) mountain-sized amount of rock was rapidly (in parts at the quoted speed of 90 mph (145 km/h), or more, lasting perhaps just half an hour) forced to slide a significant distance over younger rocks, through the action of one or other volcanic processes on and above a near-horizontal geological fault, after which significant erosion over millions of years has removed much (but not all) of the material that would give the original context.

This is humorously summarized as "49 million years ago, Heart Mountain, Wyoming slid sideways 15 miles like a giant stone hovercraft" with a similarly oversimplified functional diagram. Those not following the evidence that leads to this unusual conclusion may decide those involved do not have a normal state of mind ('are doing ok'), and potentially sliding into pseudoscience like that of Pyramidology. The geologists acknowledge this, but ask, "Hey, you come up with a better explanation!" - as all more 'reasonable' explanations have been eliminated, and only the seemingly absurd remain.

As an added bonus, the first 'European' maps of the mountain also may have placed it in the wrong position, but this was purely human error and totally unconnected to the prehistoric rearrangement of material.

Transcript

Ambox warning green construction.svg This is one of 27 incomplete transcripts:
Don't remove this notice too soon. If you can fix this issue, edit the page!
[Cueball is on the left, Ponytail is facing him from the right.]
Cueball: We haven't checked in on the Geology Department for a while. I wonder if they're doing okay.
[Ponytail is walking to the right.]
Ponytail: I'll go see what they're up to.
[Ponytail is now seen having opened a door at the left side of a room, within which White Hat, Megan and another Cueball are looking at a chart on the wall, the other Cueball gesturing towards the chart. Most of the chart is illegible, but near the top it says "90 MPH", and below that there's a diagram of geologic strata, with the label "Bighorn Dolomite", upon which a sharply rectangular and isolated rock 'block' is depicted. The rock block has speed-lines indicating its rapid movement from left to right.]
Cueball: 49 million years ago, Heart Mountain, Wyoming slid sideways 15 miles like a giant stone hovercraft.
[Ponytail walks back to the Cueball from the first panel's scene.]
Ponytail: ... They're not okay.
Voice from off the right side of the panel: Hey, you come up with a better explanation!

comment.png  Add comment      new topic.png  Create topic (use sparingly)     refresh discuss.png  Refresh 

Discussion

https://web.archive.org/web/20061007150515/http://earthobservatory.nasa.gov//Newsroom/NewImages/images.php3?img_id=16819

At some point a giant sheet of limestone... detached and slid southeast towards Bighorn Basin.

Yawn. 2600:1700:2120:5880:40C3:15EB:C354:BD73 00:49, 1 November 2025 (UTC)

This being Halloween, I was really hoping for something along the lines of "The Tell-Tale Heart" mountain. 76.187.17.7 01:21, 1 November 2025 (UTC)

Hopefully The Raven is close enough Once upon an inter-blaggy as I scrolled my eyes all baggy Searching through querulous old comics on the site Quoth the explainers: “That’s not quite right” -- Salsmachev (talk) 01:33, 1 November 2025 (please sign your comments with ~~~~)

Typical, you make a properly researched link to Wikipedia and then, less than two hours later, someone makes it so that someone else has to 'fix' the link and makes me look stupid. (More stupid than I already made myself look, given I might have written other bits of it differently if I'd waited until the morning.) 2.98.65.8 19:15, 1 November 2025 (UTC)

Hi ! First Time commenter here. I wanted to note that the tone of the explanation feels weird to me (it is not specific to this comic, but to most latest explanation). It is very descriptive, dumbing down things that are obvious (panel 1, 2 and 3). I have the feeling the explanation would be better as something like "this is a joke about heart mountain [wikipedia link] <sumary of wikipedia link explaining how the exisiting theories a out heart mountain may look absurd>. Non need to paraphrase each element of the comic, but bette explain the ones that someone may not understand. Am I the only one? Is this remark misplaced? 176.133.138.237 21:57, 1 November 2025 (UTC)Sayanel

Not out of place. It's a collaborative edit, so different approaches get stacked on each other, with different ideas of what need explaining.
I personally prefer not to describe things 'as they happen' but, if I'm coming to something already with that format, I'll place the necessarily narrative expansion of details onto that basis. (In this case, though, there was mostly an appending done, not disturbing the original any more than I saw fit.)
Complete rewrites do get done though. Maybe you want to give that a go. Knowing that dewrites and re-rewrites might well follow, as well as the revamp merely being refined by others. 2.98.65.8 23:21, 1 November 2025 (UTC)

The pioneers used to ride these babies for miles! -24.177.125.170 03:21, 2 November 2025 (UTC)

If you listen closely, you can still hear the sounds of Eurobeat echoing from when they were travelling at high speed. Multi-thrust drifting to the tune of Running in the 90s Laramide Orogeny. 2.101.107.222 (talk) 10:47, 3 November 2025 (UTC) (please sign your comments with ~~~~)

Made some edits to hopefully work better. I still feel the scientific explanation is a bit threadbare, and should be written with more detail of how the conclusion was reached, but I haven't read enough to confidently rewrite that.... 216.221.83.168 16:54, 4 November 2025 (UTC)

"Recent work has focused on release of gas (CO2) along the detachment surface that allowed it to move like a hovercraft." from https://www.geowyo.com/heart-mountain.html 2600:6C54:4E00:99C:67B7:D578:30ED:2471 00:41, 5 November 2025 (UTC)

The explanation above currently says the landslide was 50-75 million years ago. However, the comic agrees with Wikipedia (and references therein) that the landslide was 48-50 million years ago, after a "period of mountain-building" 50-75 million years ago.2601:600:837F:B130:417B:6C65:C169:8DB9 19:26, 5 November 2025 (UTC)

Aside from incorporating further details and suggestions from previous comments, I have also taken the liberty to make major edits to remove what I felt was unnecessary detail or speculation. Reverting my most recent edit will restore what I have removed while keeping the details and corrections. 216.221.83.168 18:56, 6 November 2025 (UTC)

Looking good. But 15 miles traveled at 90mph would take less than half an hour. More like 10 minutes. -- OrwellFan (talk) 03:03, 15 November 2025 (UTC) (please sign your comments with ~~~~)

With a flying start (and finish) and all at 90mph, it would indeed be 10 minutes. But there'll be a start up and coming to rest. And if it's fragmented into a 'rubble pile' (albeit with mountain-sized lumps) it probably spreads out, the tailings hardly moving and slowing down early, the wavefront of the mass going much further and faster than the 'just moved by 15 miles' Heart Mountain bit.
So parts travelled 15 miles and parts went at 90m0h and either parts or (maybe) all but a bit of settling happened within just a half hour. (If anybody gets to send back some go-pro cameras through time, there could be some marvellous shots, at least until obscured by the secondary effects.) 82.132.238.20 15:32, 15 November 2025 (UTC)
      comment.png  Add comment