A meteorite by any other name…

I’m finally done with my meteorite analysis and write-up. What’s next? Blog it of course!

So, the whole point of my analysis was to determine the metamorphic grade of the meteorite. I was going to do this by using an electron microprobe to measure the calcium content of the pyroxene crystals. While the premise was simple, we had a rather complex problem. The meteorite was so shocked (probably between S4-S5) that the fracture of olivine crystals nearly mimicked the right angle cleavage of the pyroxenes. So, trying to tell the difference between the two was tricky. We had 43 points to scan and we hoped that about 15-20 would come back as pyroxenes. Here is where things get interesting.

Our meteorite should have had a composition that was roughly 60% olivine and 40% pyroxene. However, of the 43 points shot, only two came back as pyroxenes. And to top it off, the Ca content of the two was at just under one percent. This presents us with a rather vexing issue. What happened to all the pyroxene? Statistically we should have hit more than 2 crystals. Was it really bad luck on our part or are we dealing with a sample that has super-low pyroxene content? My two advisors that are assisting me with this project aren’t really sure. Either it’s an L6 chondrite or we have something really unique. And we won’t know until we get the thing on a Scanning Electron Microscope. So, until we can get a proper classification, the metamorphic analysis is on hold. I’m gonna keep my finger crossed that we have something more than an L6 on our hands.

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