mineral identification from spectrally filtered strobe light

Well, that might apply to radioactives, and possibly to oil deposits.

But when applied generally, that's the "Horganism" fallacy. Or "everything has already been discovered, we can all just give up and go home." Or "ascribing infinite capabilities to The Experts."

On the contrary, to guarantee that you find all the good stuff in easy-to-reach locations, you'd have to hand-carry a gamma fluorescence device over every square meter of accessible land. It's much easier to just follow expert predictions.

In other words, the remaining "good stuff" will be found where "the experts" are wrong.

Heh, there's one guy who drags a big scintillator across miles of landscape. Looking for fossil bones, not minerals. Apparently they preferentially retain enough radioactive material to be detectable within a few inches of the surface.

Look at and identify the plants growing there...

It is going to be pretty had to ignore the ubiquitous quartz that will inevitably be present. Very few minerals and rocks fluoresce in any distinctive way. But why use a strobe when you can do it at night?

That would be laser ablation spectroscopy. Laser ablation is used fairly routinely for rock samples in laboratories - it saves the tedious step of having to dissolve difficult rocks and ceramics.

They started off with NdYAG then graduated to doubled and then quad frequency (with a trace of green still visible in the beam). The shorter wavelength giving a tighter diffraction limited spot size.

The target could be monitored on a CCD and you would see the plume of plasma rise from each hit. It went into a optical or mass spectrometer to obtain maximum sensitivity from a tiny sampling amount. Done right you could barely see the crater resulting from the sampling.

But I think you would be very unpopular scaling this up!

Or use an XRF instrument capable of doing quick field elemental analysis of rocks and minerals at close quarters. eg:

A UV handlamp in the desert at night is interesting. Beware that as well as interesting minerals scorpions also glow well under UV.

ink BIG

CFanItAodFysAqw

Back in the '80s we flew a helicopter-based system with a large pulsed XeCl laser with a scannable mirror to direct the beam as needed. We were lookin g for tungsten (scheelite) and various secondary zinc minerals, using delay ed detection to allow fast-decaying fluorescence and scattering to be ignor ed. We had originally hoped that secondary uranium minerals could be detect ed from the air but their fluorescence life-time is comparatively long and hence not easily resolved.

The system worked but obviously needed the mineralisation to be at surface, which, in North America at least, limits its use.

JohnR

snip

I would use a big space based one to "ablaterate" humans. :-) Oh, that's right... they already made a movie of that.

My favorite laser shot still has to be the 'port' made by the mothership in "Aliens vs Predator" opening sequences.

snip

Funny, Sloman. "Speculation about specularity". How special. Just thought I'd cast a different light on things.

Where "moss and lich doth corrupt..." ??? hehehehe!

We should tap the heat in huge salt domes too, for ultra stable, ultra long term heat product. Offset the cost of making steam on the surface.

Hint: There might be some interesting possibilities in the IR spectrum too.

In fact you cast obscurity. Neat trick.

This is a BBC article indicating China is going to build a "silk road" train into Afghanistan to aid in mineral mining. A mere 100B US. Lots of luck will be required.

Pakistani spurs of the Silk Route.

China wants to exploit the mineral deposits of Afghanistan and is prepared to build a railway from Kabul to Xinjiang in China, while similar mammoth schemes are being prepared for Pakistan.

But nothing will happen until the numerous wars in the region come to an end. That includes the insurgency in Balochistan, the violence in Karachi and the Taliban insurrections in Pakistan and Afghanistan.

Den tirsdag den 2. december 2014 05.39.40 UTC+1 skrev miso:

ain

ill

so optimistically in a few hundred years ....

-Lasse