Twink Monrad
7/9/2016 7:14:01 PM |
I still like my ice age mammal theory...It was always fun to think about that after we learned that these meteorites fell at least 15,000 years ago.... |
Twink Monrad
7/9/2016 7:11:50 PM |
All interesting, thanks! And this was found with Jim beside me a long, long way from where he and John first found them so know they had not seen this rock before. And the hot rocks make a quite different sound. The Gold Basin meteorites sound just like gold:a clear zip zip as we say. It is so neat because of the tight fit of the two halves. Yes it just split apart on the crack line, I can see that now. On the "puzzle stones" to me they are obviously from impact on ground as they are in pieces of all shapes and sizes in a very small area. I should photograph some of the puzzle stones, they are very fun to see. Thanks again everyone for the great comments. |
Bob Verish
7/9/2016 3:09:49 PM |
Twink, what Ben says is true, but for the sulfates/salts to "get into the crack", some force had to form a crack. There are a variety of processes proposed, but in regards to CHONDRITES, it is widely held that post-fall weathering of iron to iron oxide, with the resultant expansion of volume of the stone, initiates the stone-splitting cracks. If all we needed were the "expansion cracks" in the fusion-crust to intiate this splitting, then we would see an equal percentage of "puzzle-meteorites" with achondrites, but we don't. |
Bob Verish
7/9/2016 3:06:14 PM |
John, I would rather like to think that Jim and John would have taken their "hot rocks" home with them (which is exactly what Jim did and how he got them recognized as being meteorites;-). Certainly no reason to lump them in with the earlier prospectors that did "throw down their hot rocks". |
Ben Fisler
7/9/2016 11:26:33 AM |
The split is from "salt wedgeing". A surface crack gets blowing salt-laden dust in it. It combines with rainwater, and swells, enlarging the crack over time. Freeze/thaw cycles speed the process. Twink, an awesome find! |
John Divelbiss
7/9/2016 10:55:35 AM |
Twink, nice big Gold Basin ...maybe this was a "hot rock" that Jim or John threw down and split in half, before someone knew they were Rocks from Space? I have earthly finds that are also split-fit rocks that I believe are caused by weathering, including freeze-thaws. |
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