The boundary of the area where the uranium concentration is high enough to be worth mining is fairly sharp. Where there is stratigraphical continuity (i.e. not a faulted contact) with the surrounding rocks, the uranium remains confined in a fairly small area. Which is fairly good from a waste containment point of view.

Uranium's behaviour as a sedimentary material in a variable redox environment is complicated.. But since we're talking about proterozoic sediments we know that the effective oxygen contend was well below 1% of current oxygen (so 0.02% absolute equivalent) because it was so long before the Ediacaran-Cambrian, Ordovician and Carboniferous increases in ppOâ ; this was the period when iron was swapping between +2 and +3 oxidation states (and in the process, buffering the redox potential of the planet's surface - the subsurface was probably controlled by the Quartz-Fayalite Magnetite buffer) ; that change in oxidation for iron results in quite drastic changes in solubility (in roughly neutral water) and the same is true for uranium (uranyl, UOâââ) ions in solution. Moving any distance away from relatively well oxygenated surface waters would, as soon as the [Oâ] decreased by microbial activity, result in the uranium salts dropping out of solution.

It was always a complex situation, and I struggle to remember the details. But Oklo isn't a good argument that geological containment of radioactive waste doesn't work. Don't forget, of course, that nuclear waste typically contains 30 or more atomic species of concern, from caesium (an alkali metal) through barium (with one of the most insoluble sulphate salts in the periodic table - a major metamorphic mineral, we had a mine not far up the road) to radon (an "inert" gas, though at the reactive end of that spectrum). That's in addition to the uranium.

but a site where uranium in the ground underwent fission without human intervention seems like the opposite of what people want in nuclear storage.

Uranium will undergo fission without human intervention. That's one of the things it does. Without human intervention. We can change the decay rate of âBe to âLi by a few % (because the near-nuclear electron density is affected by the extra-atomic crystal lattice, but for uranium there are multiple intervening electron shells to considerably reduce the effect.
Amongst other things, the human-uninvolved decay of uranium nuclei by fission is the basis of a number of well-understood systems of radiometric dating. It's a completely natural thing. So obviously nuclear waste management has to consider it.

Uranium didn't "discover" the process of fission when Becquerel put it on a wrapped photographic plate in ... I assume it was Paris, in about 1895. OK, 2 March 1896. It's a completely unavoidable process, so you have to manage it ; you can't avoid it.

I've forgotten the original topic of this thread - wasn't it something about irradiation some nuclear species with a specific wavelength (range) of gamma to change it's half life - well, change it's species - to something shorter and less inconvenient. Which is an idea that occurred to me when I was learngin about nuclear science as a dating tool in the late 1970s. But the problems remain as they were then : there are a lot of different nuclear species, requiring a lot of different wavelengths of gamma rays (stretching into the soft-X) ; and being mostly heavy metals (137-Cs is pretty low on the tree of products)), they're inconveniently radio-dense. Which means the radiation you bathe them in doesn't penetrate well into the core of the lump. but the prospect of making an inconvenient product (say, half-life 10kyr) into a more dangerous but shorter-lived product (say, 100 years) remains appealing.

I tried to work around the problems by envisaging very broad-spectrum GR(X) sources, and dissolving the shit (technical term) into a liquid, so as to expose thin films of the nucleides to the right radiation for that nucleus, and then pump it away for further processing. But the "dissolve into liquid" step just makes it as problematic as standard nuclear waste reprocessing (to produce bombs), and for a broad-band source of GR (and soft-X), really you're looking at the interior of a nuclear reactor ... so you've re-invented the wheel of a waste-fuelled reactor. Which has always been a technical possibility, but politically unpalatable. And not technically simple itself.

On the other hand, Oklo is 1.7 billion years old, and any geological structure at that age is exceptionally quiet from a geological point of view.

Not the case. The deposition of the Oklo deposit in a shallow marine setting has been followed by moderate grade metamorphic recrystallisation of the rocks, several stages of folding and fighting, as well as recent (last few million years) uplift and erosion in it's current setting.

It's not the most active of areas, but it's also not the quietest of areas. It's pretty unremarkable in that respect.

A colleague ,working with me off the coast of Gabon, took a couple of weeks leave after his hitch at work to go walkabout in Central Gabon, including trying to get access to the uranium mines in the area. If I see him again, I'll ask if he actually got to see anything interesting. Got to give him brownie points for trying.

(You're likely going to tell me that I don't know what I'm talking about. My mapping area contained rocks of approximately the same age, but metamorphosed to a considerably higher degree, then overthrust by relatively recent rocks of the Cambrian- Silurian Caledonian orogeny. My rock pile on the other hand, from about 50 miles (crow) to 100 miles (road) north contains stromatolites which are approximately a billion years old - half the age of the Oklo rocks ; and twice the age of the Caledonian faulting. The number of professional geologists in this thread is not less than one.)

Is it showing any signs of dying? I mean, the dumbfuck-in-chief may be setting up for a Porterhouse Blue, but all that means is that we'll see a succession battle between his children and whoever that bearded twat of a regent is. Which will be entertaining - particularly if the kids win, and then set in on a good family-on-family succession battle.

I remember GRRMartin saying that Game of Thrones was largely inspired by the Wars of the Roses. So assuming he's not dead yet, what is he going to be inspired to write ,by living through such warfare?

The owner or MD of a business signs the paychecks for the day-workers in your country? Here, even with pretty small companies, that's normally done by a minion.

and it promotes co-operation and teamwork.

Don't say things like that - it'll inspire fear, uncertainty and doubt amongst Trump and the tecbrodudes.

What are you - some sort of pinko-commie-subresive? Or even (say it not in Gath!) a Canadian?

America requires babies to wear helmets when driving motorcycles?

I'm surprised.

I'd have expected American motorcycle babies to be maximising their legal disruptiveness by being required to shoot passers-by. Why not - they're under the age of legal responsibility. Until it comes to the consequences of violating their NDA.

YouTube has adverts?

You mean the incessant "and here are some words from Brilliant/ some "educational toy company"/ ... actually, I can't bring another example to mind - I FF past them so fast, without engaging the brain.

Am I destroying YT? Maybe, maybe not. Do I care? Not in the slightest.

As a geologist, I obviously thought of lapis lazuli while trying to work out the name. But I didn't know the Persian linguistic connection.

Classic lapis should have flecks of iron pyrites (FeSâ, approx ; brassy-yellow, possibly cubic habit ) in the blue (frequently white-mottled) groundmass ; if you don't see that, it's probably a good idea to put the specimen down and move on to the next dealer, because you're probably being sold sodalite - and the dealer themselves may not actually know it. Now sodalite is a very pretty stone (I've got about 20 sq.cm of 8mm slab myself) ; but it isn't lapis lazuli (which I've never found a good sample of which I could afford ; though I haven't really tried hard).

Poor people in the West don't need children for labour or are afraid that the child won't survive. They still procreate.

Actually, there are some people who wail, profusely, that that is, indeed, a problem, because they don't do it enough.

I've never understood it myself, because I've never had any idea how to get the consent of my future adult children for the life of unmitigated misery they're going to suffer, before conceiving them. But some people do indeed seem to think that inflicting misery on their children is their right. And they're very vocal that doing so should become your obligation to ... somehow dilute the evil of their choices?

Yeah. Some people, eh?

So 2026.

So MAGA.

So ... he has some deal with Nielson (sp? the TV ratings organisation) to somehow monitor people's vision of the sky, and how effective the adverts are. Because if you're selling adverts, at some point the customer is going to ask "are my adverts reaching the right eyeballs and leading to more sales.

Yes, I am anticipating, for example, a new (?) use for all those under-employed Google Glasses. Should have the correct range of sensors and communications to do the job.

You think it won't have a viewing proposal evaluation committee, and a distinct time-allocation committee? Seriously?

How do you think telescope time will be allocated? Votes on some website? Likes on Facebook? In which case, you can guarantee that the "Moon Landings were a Hoax" idiots will at some point game the system to burn out the sensors and claim proof that the Moon Landings did, indeed, never happen. That, or the Tangerine Shitgibbon will annex the telescope and require it to search minutely for proof of the non-existence of Democrat-inspired Moon Landings.

Oh, it's an AC. So an opinion that is not worth considering. Sorry for feeding the AC.

Yeah, you really don't get the "wilderness" thing, do you?

What did you think of Tejado-Flores' analysis in "Games Climbers Play"? I think it amply punctured the nature of the game in expedition climbing, and a full decade before the first oxygen-free ascent. Anyone playing the expedition game these-decades knows they're a failure before they start.

Yeah, you really don't get the "wilderness" part of mountaineering, do you?

Elevators all the way to the summit.

This would be much more effective if it applied to all countries with scenic mountains. Shit on one country's mountains ; discover that other countries with nice mountains won't let you off the plane.