Did the explosion under Giant Rock cause its cleaving 58 years later?

January 23, 2025 10:48 AM

Wikipedia: Giant Rock is a large freestanding boulder in the Mojave Desert near the 29 Palms Marine Corps Center and Landers, California (whose residents are sometimes referred to as "Landroids"). The rock cleaved in the year 2000, the day after a group of devotees held a Long Dance at the nearby Integratron... but the story really begins in 1931, when Frank Critzer arrived. He burrowed out a space underneath the rock where he lived for many years, until he "perished in a self-detonated dynamite explosion in his underground rooms on July 24, 1942, while being investigated by local police."

Visit Joshua Tree has a brief introduction; Cult of Weird has more info on the Interplanetary Spacecraft Convention first held there on March 1, 1954, and then every year thereafter; but the Mojave Project has the most detail in Giant Rock, Space People and the Integratron.

The Integratron, previously: The Fountain of Youth

Bonus: Huell Howser visits Giant Rock (California's Gold #3011)

posted by Rash (20 comments total)

Arguably, a "new era" was revealed by the cleaving. Unfortunately.
posted by Halloween Jack at 10:59 AM on January 23

So what you're saying is that we can fix this timeline if we simply reattach the rock?
posted by RonButNotStupid at 11:16 AM on January 23 [6 favorites]

RonButNotStupid: So what you're saying is that we can fix this timeline if we simply reattach the rock?

I foresee a flashmob to rival that dumb Area51 thing.

See you there. I'll bring the concrete patch.
posted by xthlc at 11:30 AM on January 23 [2 favorites]

By Gelfling hand or none at all.
posted by Horkus at 12:15 PM on January 23 [14 favorites]

So how did it get there?

It seems too far south to be a glacial erratic, and if it rolled from somewhere you might expect the track to last for at least centuries under desert conditions . . .

I tried looking at aerial photographs but couldn't tell a thing, basically.
posted by jamjam at 12:25 PM on January 23

cw: That UK lightnet link leads to Maximum Woo. Don your tin foil trilby before clicking.
posted by CynicalKnight at 12:44 PM on January 23 [2 favorites]

>So how did it get there?

Joshua Tree NP has many such rocks -- I don't quite know why this one gets singled out.

I'm not a geologist, but sandstone would indicate some sort of ancient sea shore I believe? Here in Boulder we have sandstone that's... somewhat similar from the shallow inland sea that once was here, before the Rocky Mountains rose and pushed them all up into things that look like flatirons (which I find funny, since no one knows what a flatiron is anymore).

The individual boulders would be form erosion and removable of material around the boulders, which could partly be something like a stream or river, or just weathering. No glaciation needed.
posted by alex_skazat at 12:46 PM on January 23 [1 favorite]

So how did it get there?
The National Park Service has an explainer about boulders and local geology.

Edit: (tl;dw: What alex just wrote above.)
posted by Avelwood at 12:56 PM on January 23 [2 favorites]

1. Giant Rock
2. Integraton
3. ???
4. Profit!

But seriously - stuff like this is cool, due to the ...interesting people it attracts, and the aesthetic and overall vibe of being unusual.
posted by davidmsc at 1:32 PM on January 23

Rock of Ages cleft for me,
For a slightly higher fee
posted by ocschwar at 1:51 PM on January 23 [2 favorites]

cw: That UK lightnet link leads to Maximum Woo. Don your tin foil trilby before clicking.
posted by CynicalKnight at 12:44 PM on January 23

This would be eponysterical if not for the fact that the lightnet article is indeed extremely woo... and should defintely be taken with at least a grain of rock salt.
(Sorry, I'll see myself out.)
posted by BigHeartedGuy at 2:12 PM on January 23 [1 favorite]

I was curious what Frank Critzer was being investigated for, and it was apparently because of local paranoia that he was a German spy, it being WWII.
posted by tavella at 2:13 PM on January 23

Woodson Mountain near San Diego has hundreds of boulders like this - I don't know about the specifics of the granite in Joshua Tree, but the ones on Woodson just form big vertical clefts naturally, no explosion needed.
posted by LionIndex at 2:31 PM on January 23 [1 favorite]

Magnus Midtbø just climbed it.
posted by Omon Ra at 2:36 PM on January 23 [2 favorites]

gneiss post. my geology professor never told us this one.
posted by clavdivs at 4:20 PM on January 23 [5 favorites]

Big Rock is not sandstone but white granite, yet axelwood's link makes it clear that your ideas of erosion and weathering are otherwise exactly right, alex_skazat.

As for the cause of cleavage, I think it's interesting that in mid-October 1999, a few months before Big Rock split, that area of the Mojave experienced its biggest earthquake in 100 years, the 7.1 Hector Mines quake, which actually caused the ground to rupture at 29 Palms.

I'd be comfortable attributing the split to the quake except that the lightnet link claims four people observed ball lightning inside the Integraton center two hours after the Rock broke in two.

Breaking apart a piece of granite that big might well involve enough quartz crystal stress and strain for piezoelectricity to generate the kind of plasma I see as the most reasonable hypothesis for the source of ball lightning, but for it to hang around in the air for hours is a stretch even for credulity as elastic as mine.

However, big pieces of jointed granite rubbing together underground and the resulting plasma percolating to the surface hours later seems like a more reasonable idea.

There were a couple of 5-ish aftershocks of the Hector Mines quake, but I didn't see any dates for them.
posted by jamjam at 6:50 PM on January 23 [3 favorites]

While we're on the subject of giant rocks, it looks like the Madison Boulder in NH is the largest glacial erratic in the U.S. It was carried at least 2 miles and perhaps as much as 24 miles by the glacier. State Park web site. It's also been claimed as the largest rock in the U.S.

I don't know the exact size of the Giant Boulder, or which of the two is actually larger. But just from the photos it looks to be roughly on the same scale as the Giant Rock: H-u-g-e.
posted by flug at 7:05 PM on January 23 [3 favorites]

See also the large boulder the size of a large boulder at Erratic Rock State Park in the Willamette Valley in Oregon. A friend who runs the museum at the Confederated Tribes of Grand Ronde says the place is considered semi-sacred because it’s a nice place to sit and watch the sunrise.
posted by Just the one swan, actually at 9:17 PM on January 23

Someone wasn’t trying very hard with that name.
posted by gottabefunky at 9:18 PM on January 23 [1 favorite]

I've been to the Integraton. It's a nice way to spend 45ish minutes lying on the floor looking up at a domed ceiling listening to crystal bowl sounds with a bunch of strangers doing the same, but I'm not sure it's worth the $55 ticket. I have a James Randi fondness for kitschy scam tourist traps though; I had a Mystery Spot bumper sticker on my motorcycle and loved the show Gravity Falls.

Their claims that the sound from their crystal bowls have healing properties are, uh, not endorsed by the FDA.
posted by AlSweigart at 7:21 AM on January 24 [1 favorite]