779 views

Over 15,000 photos and growing!


  9 - January - 2018

This Month       Today's Picture       Select a Month

Submit a Picture

Where is My Picture?!

The Queue


Select by   Contributor

Met Name

Met Type

Thin Sections


Recent Comments

Isheyevo   contributed by Daniel Da Costa, IMCA 6758   MetBul Link


Roll Overs:     #1   #2   #3   #4    


Click the picture to view larger photos

View all entries for   Meteorite (5)   Daniel Da Costa (1)


5.8 grams.   CH/CBb

TKW 16 kg.Fall not observed. Found October 2003, Bashkortostan, Russia.

 


Daniel writes:
From the MetBul:
A stone, weighing 16 kg, was found by a tractor driver in a field during the harvest, in the Ishimbai area, in Bashkortostan, near the village of Isheyevo. A small piece of meteorite was delivered to the Vernadsky Institute by Kazakov DA and Polozkov AG, September 2004. Mineralogy and classification (Ivanova MA Vernad., Ulianov AA, MSUM). The melting crust is well developed, dark brown. The meteorite is composed of metal grains of FeNi, C, POP, rare BO chondrules (size 0.02-1 mm), fragments of chondrums, CAI and matrix lumps. The FeNi metal comprises from 50 to 70% by volume and contains 4.2 to 8.4% by weight of Ni, 0.2 to 0.5% by weight of Co and 0.03 to 0.6% by weight of Cr; The Co / Ni ratio is approximately solar. C-chondrules do not contain metallic FeNi grains, they are rich in Mg and consist of cryptocrystalline materials rich in pyroxene. Olivine, Fa 2.5, rare olivines rich in FeO, Fa 10-38; pyroxene, Fs 2.1 Wo 1.7, pyroxene rich in FeO, Fs 8-12 Wo 0.8-1.8; the troilite is rich in Cr, 2.5% by weight of Cr. INAA data for a 20 mg chip: 2.74% by weight Ni; 717 ppm Co; 2608 ppm Cr, 8.2 ppm Sc and 1.59 ppm Ir. Petrological Type 3; shock stage, S1; grade of alteration, W1.

A team from the Museum of Mineralogy and Cosmochemistry of the Museum (UMR 7202 MNHN / CNRS) associated with researchers from the University of Florence (Italy), the Laboratory of Structures and Properties of the Solid State and the Laboratory of Planetology of Grenoble, reports, in an article to be published this week in the PNAS, the discovery of a strange inclusion in the meteorite of Isheyevo. The mineralogy of this inclusion (anhydrous silicates of magnesium and iron) is similar to that of some Antarctic or stratospheric micrometeorites. It could indicate a cometary origin. However, this inclusion measures ~ 0.5 mm and therefore has a volume 30000 times higher than micrometeorites.

Measurements made with NanoSIMS have shown that this inclusion, called PX18, has an isotopic composition of nitrogen (proportion of various isotopes of nitrogen) extremely variable. It is, in particular, 4 times richer locally in heavy nitrogen (15N) compared to the isotopic composition of the Earth. This enrichment is the largest ever observed in extraterrestrial matter. Areas rich in 15N correspond to organic matter. These enrichments in 15N will allow researchers to better understand the mechanisms of formation of the organic matter of meteorites. It is possible that complex phenomena of irradiation by the protosoleil (ancestor of the sun) have generated this abnormal isotopic composition. The discovery of this inclusion poses many problems to the current models of solar system formation.
Click to view larger photos

#1

#2

#3

#4

Found at the arrow (green or red) on the map below

 


Comment on this MPOD                      
Name
Comment

980 max length

  Please - NO Dealer Ads in the comments
but pictures from dealers are gladly accepted

Tomorrow

Tourinnes-la-Grosse
Hanno Strufe

This Month

1 picture in the Queue
John Divelbiss
 1/9/2018 7:06:19 AM
Isheyevo is certainly one of our stranger meteorites...as are Gujba and Bencubbin from the same family.
 

Hosted by
Tucson Meteorites
Server date and time
3/28/2024 7:47:22 AM
Last revised
12/31/23
Terms of Use Unsubscribe