Veins of shock ?

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Veins of shock ?

Postby chasseur » Thu Oct 06, 2016 4:46 pm

Hello all, I am a meteorite hunter and I would want asked a question on observations made in a thin section.
This thin section show many red veins like impact veins.This rock are basalic .Think you that it is possible, that these veins are a chock veins ?
See pictures thank you .
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veine 3.jpg
veine 2.jpg
veine 1.jpg
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Re: Veins of shock ?

Postby Barwellian » Mon Oct 10, 2016 9:30 am

I would say that if they were shock veins then they would be dark and glass like...so more likely terrestrial weathering products in a vein.

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Re: Veins of shock ?

Postby chasseur » Mon Oct 10, 2016 12:10 pm

Hello Barwellian , I agree this veins are oxidized, but they are oxidized as the veins of shocks of mafic composition (oxydised mafic glass) that there is in lots of meteorites (see joined pictures of veins in chondrites,below)).Have you some exemples for illustrate your comments ?
Thank you
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7e2f99baabc8a9cc6cb6d0bf475deffa.jpg
Picture 704.jpg
veine chondrite.jpg
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Re: Veins of shock ?

Postby Barwellian » Wed Oct 12, 2016 10:42 pm

Hi Chasseur,

Th pictures you show of chondrites with veins do not look like shock veins either to me...I see these many times as veins that occur due to terrestrial weathering not connected with shock in the same sense as the shock recorded in their classification....that shock happens in space from massive impact forces and those veins rarely weather in the same ways as you as you show....the melt shock veins still show thousands of years after they have sat on earth and are different from cracks formed on impact with earth or due to weathering which fill with weathering products. (I have friends who have found meteorites that have been dated as falling nearly 300000yrs ago which still show unchanged shock veins)

http://meteoritegallery.com/nwa-5744-lunar-troctolite/
http://www.meteoritestudies.com/protected_NWA2977.HTM
http://www.meteorite-times.com/Back_Lin ... n_Desk.htm
http://www.meteorite-times.com/accretio ... om-heaven/

I agree with you that sometimes a shock vein in a meteorite might also form an entry point for weathering products over time, especially if it is a weak point in the matrix...but I would say that is much rarer than common weathering fractures and veins and that can be seen often in terrestrial rocks.

Would help to know where your basaltic rock is from and details about why the thin section was made....was the original rock obviously like a meteorite when found and before it was curt and a thin section made?...these details make it much easier to work out what it is....if that is what you are investigating.
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Re: Veins of shock ?

Postby chasseur » Thu Oct 13, 2016 10:44 am

Hello Barwellian , can you to show me an picture of terrestrial rocks with the same veins ? I need this for to compare.I looked on the net and books but I did not find.
Thank you
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Re: Veins of shock ?

Postby Barwellian » Thu Oct 13, 2016 9:00 pm

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Re: Veins of shock ?

Postby chasseur » Fri Oct 14, 2016 10:28 am

Hello Barwellian.
Thank you for your interest , the veins seen in your pictures have not resemblance with the veins in my samples , it is clear .I think that the veins seen in your pictures is just a metamorphic vein , for one , and the second is an crack filled by calcite , or zeolite , or glue or other (normal weathering in surface rock) . In my samples , the veins are the same color and morphology that the meteoritic veins in my pictures.
Here are two interesting article:
http://www.geochem.geos.vt.edu/fluids/p ... 163_HI.pdf
http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2478.pdf
Here is the rock which I propose you as possible meteorite:
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Picture 011.jpg
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Re: Veins of shock ?

Postby chasseur » Fri Oct 14, 2016 10:31 am

This rock is a basaltic breccia type basanite / téphrite (i have pay many chimical analysis for to know that) , very common Earth it is true, but this type of rock, was find on Mars by the rover Spirit (rocks Wishstone and Champapne) on the Gusev crater !
http://citeseerx.ist.psu.edu/viewdoc/do ... 1&type=pdf
According to you, would have he a possibility, even tiny , that my rocks is a Martian meteorites?
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Re: Veins of shock ?

Postby Barwellian » Fri Oct 14, 2016 12:17 pm

There is always the possibility...I always live in hope that some of the unusual ones turn out to be meteorites....the Moroccans have found many new ones lately that would have been ignored in the past because they look terrestrial and they are all likely from large differentiated bodies, either unknown or known.

Although I think it is very unlikely yours is a meteorite, if you are convinced by your research that it might be then the only way forward is to get it officially analysed by an expert meteoriticist using oxygen isotopes. You should contact one and share your images and research and see what they say. I have around 50 being classified at the moment and I visit there again soon to do more work on them for the next stages of classifcation....I am lucky that they allow me to join in and help with the procedure. If you wanted to send me a small sample then I could take it with me and see what their reaction is, but they would want to know more about the circumstances of your find, location etc before they would do that.
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Re: Veins of shock ?

Postby chasseur » Fri Oct 14, 2016 2:33 pm

Hello Bawellian.
Of course the chances exist but her are low.
I began the meteorite hunting 1994 and i have make others hunting in 1995, 96,97,98, 99 and 2000 and 2003 . I found this rock in January, 1998 in Algerian Sahara. I too discovered some chondrites, 2 el Açfer and 4 el Atchane ( mb100 ) it is little but I have height of the other finds which were refused by the laboratory in France ( As the rock which I present here this rock are presented at the laboratory in february 1998). And you have say “the Moroccans have found many new ones lately that would have been ignored in the past because they look terrestrial and they are all likely from large differentiated bodies, either unknown or known.” .We understand ourselves. I agree for to send to you a sample but I am not interested in the analysis of the isotopes of oxygen, that which interests me it is to know if this rock is shocked, simply.
No shocked=no meteorite
Shocked=meteorite or impactite, and we can start analyses more expensive.
Okay ?
In the reg el açfer in december 1997.
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reg el açfer 1997.jpg
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