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Roll Overs:
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Copyright (c) Photo by Andreas Koppelt.
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936.5 grams. Iron, IIG
TKW 20.69 kg. Fall not observed. Found 9 May 1984, Twannberg, Canton of Berne, Switzerland.
1 of only 6 meteorites with this classification.
Andreas writes:
Twannberg Mass #TW611
The Twannberg meteorite is chemically a rare IIG iron and structurally a hexahedrite. Ongoing scientific research shows that the Twannberg meteorite fell 200,000 years ago (+/- 20,000 years). In the absence of a widmannstätten pattern, oxidation is rather moderate and shale is mostly present only on the surface of the pieces; some pieces even showed delicate flowlines and original fusion crust.
All the pictures show Twannberg individual #TW611. I found TW611 on August 19, 2016. The weight uncleaned was 936.5 grams; cleaned 898 g; after cutting and polishing/etching 846.2 g. Picture No. 1 shows the individual in situ (coordinates 47° 7.408' N 7° 7.058' E). It is the second biggest mass I found in almost 4 years of searching for Twannberg meteorites. On the studio-photo (picture No. 2) some remains of regmaglypts are still to be seen. In December 2016, Marc Jost cut TW611 with the diamond wire saw (picture No. 3). We etched one halfcut and polished the other. The results are seen in pictures No. 4 to 7: The interior of TW611 reveals rhabdite layers, nicely shaped golden colored schreibersite inclusions as well as many crisscrossed neumann lines.
HAPPY NEW YEAR TO ALL THE METEORITE AFICIONADOS OUT THERE!
Note: photos 8 and 9 are closeups extracted from the original photos by the MPOD moderator. |
Click to view larger photos
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Found at the arrow (green or red) on the map below
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Andi Koppelt
1/2/2017 3:04:23 AM |
@Larry: Main reason for ist slow oxidation is for sure the missing widmannst*tten pattern; so oxidation ist just possible on the outside of an individual. And in general the terrestrial age of iron meteorites seems be much higher than assumed at first sight. Some iron meteorites, e.g. Carbo and North Chile (they can show alpha2-zones, too!), show incredible low terrestrial corrosion rates of only 1 mm per 100,000 years for the fusion crust and alpha2-zone seems to be rather durable (Buchwald V., 1975, Handbook of iron meteorites, Vol. 1, p. 140f). But I agree 100% that the slow Twannberg oxidation is rather surprising with regard to the moist region of its fall. |
Larry Atkins
1/1/2017 4:42:49 PM |
Nice Find! I'm surprised these meteorites still exist having fell so long ago.
Thanks for the in - situ shot! |
Andi Koppelt
1/1/2017 12:43:11 PM |
Thanks for all the congrats :-)
@Mark: Indeed, its a Deus XP; I like this detector a lot: No cables, almost no weight, programmable and enduring!
@Steve: Keep on trying, never give up, then the meteorite comes to you.
@Matthias: I*ll send you a pm ;-) |
Matthias
1/1/2017 5:00:17 AM |
What a majestic, almost fist-sized and sculpted iron, playing in another league than the nice small ones Team Twanny showed last Ensisheim. In contrary to the more or less regular Widmannstaetten patterns of other irons the internal structures of this one really look like hidden messages - why not hanging up comfortably in an alien spaceship and cruising the Milky Way with a little help of such a half-stone?
Congrazz, Andi, and: a good year 2017 for you and all the other dreamers. Matthias |
John Divelbiss
12/31/2016 5:21:50 PM |
congrats on the hunting success for this beautiful meteorite |
Adri*n Contreras G*mez
12/31/2016 12:46:11 PM |
Qu* maravilla! Enhorabuena y feliz a*o 2017 a todos. |
Steve Brittenham
12/31/2016 10:34:20 AM |
Hi Andreas. What a wonderful find! I envy people like you who have been able to go out in the field and come across such amazing specimens (all of my attempts have been futile!). Congratulations, and thanks for sharing. |
Herbert
12/31/2016 7:31:50 AM |
Many thanks for sharing these images and the stroy behind it, Andreas. And, above all: Congratulations to this exciting find!
Happy new year to all of you! |
Graham
12/31/2016 4:53:22 AM |
Nicely documented Andi. |
Mark Bowling
12/31/2016 2:22:02 AM |
Nice, I enjoy seeing in field photos! Is that an XP?
Congratulations!
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Oliver Sachs
12/31/2016 1:43:45 AM |
Cool photo :) |
Tomasz Jakubowski
12/31/2016 1:07:46 AM |
Amazing find Andi!Congratulation |
MexicoDoug
12/31/2016 12:41:14 AM |
Fantastic finds of this Swiss treasure Andreas! Great detective work and tenacity = Congratulations twice on the finds! Happy New Year's Eve! |
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