Analysing the Moon Rock

Posted March 19th, 2009 by admin

Friday saw me once again wending my weary way to London.

This time I was going in to carbon coat my lunar meteorite thin section and put it in the machine to make X-ray maps of specific elements. I felt very nervous as I hadnt done anywhere near the amount of reading I had ment to do for it what with boundary disbutes and work stuff etc…

And I had been highly confusing myself by trying to learn lunar mineralogy from scratch – complete with minerals I have never heared off! I had started making a list of elements mentioned in association with lunar minerallogy and then side tracked myself – turns out if I had completed this it would have been a very good start – oh well.

I was a bit sad when I arrived that the sample was already in being carbon coated – I assume the machine works by some sort of spluttering of carbon. You coat the sample to help get a clearer image by stopping alot of the interference(I think). This means I only got a pic of it carbon coated thin section and my hands were shaking so its not a very good picture anyway but this is a piece of the moon that fell to Earth in a meteorite that Landed in Africa.

The Carbon coating machine: the carbon coater

My piece of carbon coated moon rock! carbon coated moon rock sliver

This means I also have to be weary of terrestrial contamination when analysing it.

I took photos of the machine and bits around it!

explosive gases for the machine the machine complete with liquid nitrogen

What I have done for the mini project is just selected one breccia clast/grain out of this thin section from a few cubic cm’s of lunar meteorite to ananlyse. This really is looking at the fine detail – I always have to remember that it is part of a system, part of a big over all picture, the small makes up the big and the big affects the small.

We chose which elements to map for, then defined the mapping area which was just slightly bigger than the clast. An important fact is that no matter how good the polish on the surfacce of the section it is not completely flat so to get golod results you have to sort of take the four corners and average them into a focus plan. At least this is what I understood to be happening.

Anyway I selected with some help the elements that I wanted maps for and the grand total time was 56 hours running time for the machine – wowowow. Of course this is why I was in there on a Friday afternoon so that I could have the machine run over the weekend – I clicked the button to start it and away it went.

I then proceeded to make a fool out of my self by saying – its obviously regolith isnt it – erm… we dont know came the reply. I am also very intreged by the clast I have chosen to analyse – it looks like two main minerals interlocked in some sort of intergrowth way – each with its own specific selection of other mineral inclusions.

I am a bit worried that I just dont remember enough mineralogy to do this project justice :/

Still I think I may have some idea of whats going on but suffered that thing of not wanting to say anything incase I was wrong and they thought I was stupid and wasting their time and effort. I now need to go and work out the correct scientific termonolgy instead of inventing my own – again.

Still I got to take pics of the sample being mounted in the machine including the adding of the highly conductive copper sticky tap that also keeps it in place!

mounted for analysation

copper tape

There was one interesting point – the machine appears to do a continues scan but it doesnt it stops every …. and ‘dwells’ for…. this leads me onto something else I have been pondering recently – how different are analogue and didigital – you came make one appear as another depending on resolution etc… but this needs a me to do a bit more thinking and maybe write a few books on the nature of existance I feel!

Once I have worked out the mineral phases in the sample – which I will do from these elemental maps I will be putting it in the microprob for furthure analysis.

I think that for my oral presingtation and poster I will therefore need to focus on what we know of the moon from meteorites rather than just what we know about the moon.

I am getting very excited about all this – its the thought of being able to tie in the mineralogy of crystals grains within a clast with a brecciated meteorite to lunar and even solar and possible even universe formation processes!

Happyness is once again rock shaped. Though I am hoping the element doesn’t blow over the week end – it was a new one this week so hopefully it will last!

(This post also appears on my family blog Snell-Pym)

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