Lanthanum and the Ancients

[Gadrin]

Lanthanum: A rare earth element, the first of the inner transition metals. Vital to the construction of the inner coils of interstellar jump drive units.

Well, I'd been reading the Zhodani Core Expedition articles in Security Leak mag Security Leak: Zhodani Core Expeditions and overall I liked it. When I got deeper into the article I saw the encounter charts and the mentioning of finding possible Ancient sites along the core route.

Which got me thinking:

How important is Lanthanum to the Ancients ? I belive the "regular Droyne" use it in their jump-capable craft (per Gurps Trav Alien Races 3) but I don't see the ship in CT ADV 12 Secret of the Ancients being "standard", of course Grandfather operates at GTL15+/TTL 18-20+ so ...

Anyway, I'd thought that if Grandpa's ship only could do J-6 then it's likely to be constructed similarly to normal or average starships in the TU. Obviously Grandpa has the advantage of using pocket unis to store fuel and even lanthanum, but it has to come from somewhere...right ?

So it *might* be possible that ancient sites along the Zhodani core route might be lanthanum mining sites, perhaps not all marked with "Grandpa was here" and filled with disintegrators and shimmersuits and teleportation portals and so on.

I'm thinking it's not unreasonable that the psionic devices found by the Zhodani, might lead to these sites, before they were completely depleted, being useful at the time to those who created the device.

Also, any chance that regular droyne or chirpers might make the trip with the Zho's ?


Any thoughts ?

 

[Malenfant]

Don't get me started about how there's no such thing as "lanthanum ore" that can be easily mined

. The reason it's called a rare earth element is that it's *rare*, it's never found in its free elementary state, it's found in very small amounts in minerals like Monazite and Bastonite, and is apparently hard to separate from other REEs ( see http://www.webelements.com/webelements/elements/text/La/geol.html , info on the extraction process can be found at http://www.webelements.com/webelements/elements/text/La/key.html under "Isolation" )

The laws of chemistry being the same everywhere in the universe, this is likely to be how it's found everywhere - in small amounts locked up with other elements.

It's certainly not that it's impossible to find (it may perhaps be easier to melt down metallic asteroids if you want it in larger amounts?), but it's not like people can just stumble on "a motherlode of Lanthanum ore" anywhere, and the minerals it's found in can only be found on the surface in volcanic deposits - but the best way to actually extract them is from placer deposits (alluvial fans etc) which require flowing liquid to form. So earthlike planets would have it in reasonably accessible form, others would be less likely (or would only have it in inaccessible form).

I just wanted to point that out so people have the right image in their minds when wondering about extraction. While Ancients might have ubertech (and as such may easily be able to extract it from asteroids for example), they're still limited by basic physics. They'd probably have extraction techniques that are as efficient as they can get, perhaps they might even be able to manufacture it from raw material in large amounts, by some kind of atomic rearrangement (high tech alchemy, basically) - that'd make the extraction technique moot then. A working Ancient "Lanthanum factory", powered possibly by antimatter or some other exotic source, would be a holy grail that nation-states would certainly go to war over.

 

[Anthony]

I believe that the rare earth metals tend to bind chemically with iron and are thus mostly in the core on terrestrial worlds. Hence the reason asteroid mining makes some sense. Other than that, I suspect planetary systems of high metallicity stars would be richer in heavy elements. Neither effect will result in specific lodes of lanthanum, though; if you're processing asteroids for rare elements you'll pull all of them out at once, and within a given system most metallic asteroids will be pretty equal.

 

[Gadrin]

so to adapt, asteroids rich in Lanthanum (rich by your standards) could conceivably collide with planets and provide them with deposits.

likely a rare enough occurance, such that the vast majority would be found in asteroids belts.

 

[Malenfant]

Actually, for once Anthony's mistaken (that said, so am I

)

A bit more rummaging around on the web reveals that Lanthanum is actually a lithophile element - that means it doesn't sink to the core, it instead gets left behind in the crust during planetary differentiation. So actually, you won't find it concentrated in metallic asteroids at all - exactly the opposite in fact. That makes it entirely uneconomical and largely pointless to try and get it out of asteroids too.

So asteroids aren't a convenient way to get Lanthanum at all - looks like the best best is in sedimentary deposits on earth-like worlds.

 

[Anthony]

Hm. Okay. I was mostly assuming lanthanum was like gold and platinum group metals, which on reflection is a wholly unjustified assumption, as they are nowhere near one another on the periodic table.

 

[Malenfant]

eh, was partly my fault for mentioning the possibility of asteroid mining in the first place.

 

[TheEngineer]

Hi !

Well, assuming ancient technology and their power production capabilities (antimatter etc...) I guess if they need Lanthanium (or any other element) they simply create it via artificial nucleosynthesis ...

Mining is for primitive civilisations ...

regards,

TE

 

[Golan2072]

Originally posted by Malenfant:
Actually, for once Anthony's mistaken (that said, so am I

)

A bit more rummaging around on the web reveals that Lanthanum is actually a lithophile element - that means it doesn't sink to the core, it instead gets left behind in the crust during planetary differentiation. So actually, you won't find it concentrated in metallic asteroids at all - exactly the opposite in fact. That makes it entirely uneconomical and largely pointless to try and get it out of asteroids too.

So asteroids aren't a convenient way to get Lanthanum at all - looks like the best best is in sedimentary deposits on earth-like worlds.

Hmmm... But won't it be more common on non-metallic asteroids (chrondites, carboneceous etc), especially these ejected from collisions of other rocks with planetary crusts?

Also, what about the Lunar regolith (or similar airless-world regoliths) - with very little chemical erosion, won't Lanthanum be more available there?

 

[Malenfant]

Not really. It's concentrated more in the crust, but there's not a lot of it there anyway. There isn't even a mineral that's composed predominantly of Lanthanum (like say, pyrite (FeS2)). Without any means to concentrate the minerals that do contain it - ie some erosive process that removes it from rocks concentrates it somewhere else - it's just scattered in tiny amounts throughout the whole thing.

 

[Plankowner]

So, would a sea water filter work?

 

[Anthony]

Filtering sea water is generally not an efficient source of anything other than salt, and it's a terrible source for La. La is much less common in asteroids than in the crust; per http://www.webelements.com/webelements/elements/text/La/geol.html the occurrence is 2 ppb in the sun, 290 ppb in carbonaceous asteroids, and 34,000 ppb in crustal rocks.

While there is no pure La ore, there are ores that consist of rare earths, and monazite and bastnasite are the common ores.

 

[Gadrin]

Originally posted by Malenfant:
Actually, for once Anthony's mistaken (that said, so am I

)

A bit more rummaging around on the web reveals that Lanthanum is actually a lithophile element - that means it doesn't sink to the core, it instead gets left behind in the crust during planetary differentiation. So actually, you won't find it concentrated in metallic asteroids at all - exactly the opposite in fact. That makes it entirely uneconomical and largely pointless to try and get it out of asteroids too.

So asteroids aren't a convenient way to get Lanthanum at all - looks like the best best is in sedimentary deposits on earth-like worlds.

sedimentary deposits...

 

[Malenfant]

Yes, sedimentary deposits. Things like sands and muds and clays.

On earth the minerals that contain La are found mostly in placer deposits (i.e. river sediments). Seawater, as Anthony stated, is going to be useless because any La in there that is deposited by rivers is going to be very very diluted.

Think about it this way, La is concentrated in the crust. Rivers and winds erode the crust and can mobilise material and concentrate it by various means in one place (take gold for example - people sift for gold in rivers because the river acts as a way of extracting and concentrating the gold that is in rocks upstream and making it more accessible). If the river dries up, then the deposits can be lithified (turned to rock) over time and that can concentrate the minerals.

But when the river flows into the sea, the minerals in the riverwater just get mixed in with the massive volume of the ocean that it's pouring into. So you've lost the advantage of concentrating the minerals in the river environment is lost.

 

[Gadrin]

yeah, I understood, I had more to post but erased it accidentally.

how effective would a densitometer be in identifying different deposits ? (not just lanthanum) I don't expect it to be like Trek sensors where they push a button and know everything about the next five light years, but I'm just looking for a setting-tech way to give scientists a leg up in the process.

I had envisioned finding Lanthanum on a ice-age world (perhaps leaving such a period after all these posts) and possibly identifying certain geological formations via sensors Scouts might employ. The zho core expeditions strike me as long investments in time and resources such that A) they have the time to look and B) they'll need things like Lanthanum to build/repair vessels that are going to be out there for decades.

 

[Malenfant]

OK, was wondering what you meant by your enigmatic last post.

I'm not sure how effective densitometers would be, it all depends on how they work. I guess I've assumed that they can somehow figure out the density of a material by seeing how many neutrinos they absorb or something.

Today (he says, putting on his exploration geophysicist hat) one of the tools we have for surveying for minerals is the gravitometer. That basically tells you what the local gravity field strength is to a very exact number (millionths of m/s2). You take a survey (by land or plane), make adjustments for local landforms, geoid strength, and so on, and you should be able to get from that a distribution of mass concentrations in the terrain below. Ore bodies would usually show up as mass concentrations, and you can use that alongside other surveying methods like magnetometer and resistivity and seismic to figure out the size and shape and composition of the ore body. This is all highly interpretative though, there's often not a single solution to explain what you're seeing so that's why the other surveying methods should be used to narrow things down somewhat.

Frankly, I don't think those techniques would change that much in the future - the tech would be refined, and specialised densitometers may add something to the mix, but they're not magic x-ray machines that let you see geological structure hidden under the surface.

I don't think Lanthanum minerals would really show up in a gravity survey though. They must be able to find them somehow today, but I get the impression that they're extracted as a byproduct from more profitable deposits today - not searched for specifically.

 

[Gadrin]

Originally posted by Malenfant:

Frankly, I don't think those techniques would change that much in the future - the tech would be refined, and specialised densitometers may add something to the mix, but they're not magic x-ray machines that let you see geological structure hidden under the surface.

I don't think Lanthanum minerals would really show up in a gravity survey though. They must be able to find them somehow today, but I get the impression that they're extracted as a byproduct from more profitable deposits today - not searched for specifically.

great, thanks, that's good to know.

I was looking at the gurps rules for the ultrascanner ( a relative of the densitometer) trying to figure out that by scanning an area if you can scan x # of meters but can't in some circumstances, it might be indicative of a range of ores or geological types, which then require further, in-depth analysis.

My inital reaction to the Lanthanum issue, is that since there are tons of starships in Traveller uni, that it's not too hard to find. Just looking for an in-game reason to exploit.

nice posts BTW.

 

[Malenfant]

Yer welcome

Of course, people are free to armwave this all way and do whatever they like in their games if they think realism gets in the way... but I think this makes things a bit more interesting.

Having said all that, I did find this:
http://geology.csupomona.edu/drjessey/fieldtrips/mtp/mtnpass.htm

It's a mine where there's a rich carbonatite complex that contains lots of rare earths, including Lanthanum. How much is extracted there, I don't know. But it does mean that rivers aren't the only places to find the stuff, though they clearly do concentrate it somewhat. It also shows that the prospectors were originally looking for uranium ore, but instead found this. I suspect the only reason the mine is economical is because there's such a variety of REEs to extract there (I presume the raw material is actually processed elsewhere though to get the individual elements out of it).

However, carbonatites are rare igneous rocks formed in unusual conditions, and are usually found as intrusions (apparently only one volcano has erupted carbonatite lava in historical times, and it erupted lava that was only about 500°C - half the temperature of the stuff that erupts at Hawai'i). These rocks also don't play well with water, reacting very quickly with them.

These sites have a bit more info:
http://www.geology.sdsu.edu/how_volcanoes_work/Unusual%20lava.html
http://en.wikipedia.org/wiki/Carbonatite

The jury is still out on how they form - it could be from alteration and melting of carbonate-rich crustal rocks, or they could be primary magmas that come from a source deep in the mantle with weird chemistry.

So this is another possible, but much rarer option - again I suspect you'd need a large, volcanically active, watery world (they're usually associated with continental rifting) to have any chance of finding these. And again, these are very rare on Earth.

 

[Jeff M. Hopper]

Guys, when thinking about Lanthanum and the Ancients, I don't believe that ya'll are thinking big enough. The Ancients were pretty powerful technologically, remember.

Now, if my astronomy is remembered correctly, type-S stars have strong spectra for zirconium oxide and lanthanum oxide. This would mean that the solar winds from these stars would also have a high percentage of lanthanum oxide in their composition. So instead of digging in the dirt for the lanthanum bearing minerals, why not just set up a collector in a nice orbit around the type-S star and catch the wind?

I can envision a large magnetic scoop built like a cross between a Zubrin magsail and Bussard ramjet in orbit around the star, sucking in the solar wind and filtering out the lanthanum oxide for processing into lanthanum. The device would be huge (kilometers in size), probably lens-shaped (due to the magnetic field generators), and would most definitely make for a nice Ancient's Artifact for players to explore.

Likewise, with the control over the strong and weak nuclear forces implied by the Meson Screen and Nuclear Damper, lanthanum could very well be created by fusing together lighter elements until you achieved the amount of lanthanum you wanted. There would be an incredible amount of energy used in this process, though - but the Ancients never seemed to have a problem with generating power.

As in all things, YMMV.

 

[Malenfant]

I do suspect that a race with Ancient-level tech would probably use some kind of ultratech "matter-forge" to make any element they liked from subatomic particles - it'd border on "nucleosynthetic alchemy". They'd be able to manufacture any material or element they liked.

I think you're right about the La in the spectra from some giant stars, but IIRC those S-type stars are pretty darn rare. I'm also not entirely sure if the spectra means that the solar winds would have that stuff in there too, it may just be trapped in the photosphere. And if it was in the winds, it'd be very rarified too - it'd be much easier and more accessible to just dig it out of the ground.