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Sunday 5 February 2012

NWA 969 LL6/7 Chondrite

NWA 969 LL6/7 Chondrite


NWA 969 LL6/7 Chondrite IV - 2100X
(c) 2012 Tom Phillips - All Rights Reserved
NWA 969 LL6/7 Chondrite III - 760X
(c) 2012 Tom Phillips - All Rights Reserved
NWA 969 LL6/7 Chondrite VI - 400X II
(c) 2012 Tom Phillips - All Rights Reserved
NWA 969 LL6/7 Chondrite I - 160X
(c) 2012 Tom Phillips - All Rights Reserved

NWA 969 LL6/7 

I can't quite explain why, these are just about my favorite meteorite micrographs. Yes, the material is interesting, and that is undoubtedly part of it, but I just like the colors I guess.

The color change from one image to the next is a result of thin section rotation in the cross polarized light. I was using a full wave retardation filter on this set as well.

The first pair has an (At the eye piece) magnification of 160X, followed by 400X, then 760X and, just for the fun of it, I worked in a 2100X shot of some where within the original field of view. The quality of image, at that level of magnification, is not all that good and I know I said this was an "ART" site but indulge me. I just wanted to show it off. I would also like to note, this progression of magnifications was done on the microscope and was not a digital trick. Any of you who work with thin sections in Xpol know what goes into magnification changes. I spend much more time focusing the condenser than I do the objective!

This NWA 969 description was written by Adam Hupe:
Northwest Africa 969 is an extremely rare LL6/7 type chondrite with fluid trains found in June of 2001. What makes this chondrite so interesting is that it was first mistaken for a Brachinite. Its composition, ratios and 120 degree triple junctions appeared identical to that of Brachina. The few differences being sparse oriented intergrowths (interpreted as relic chondrules) chondrules and actual trains of fluid in the olivine. Only after exhaustive testing and oxygen isotopes was it determined to come from the LL chondrite parent body. More interesting is the way the fluid (water?) is trapped. It is contained in small round cavities in the olivine grains forming bubble trains, which can be observed with a microscope in thin section. We refer to this fluid as 4.5 billion year old bottled water. Although water has been found in a few other chondrites, it was contained in halite (salt) crystals not cavities in olivine making this a unique meteorite.

For more information please see the 88th Meteoritical Bulletin

Friday 3 February 2012

NWA 960 Rare Anomalous Chondrite

NWA 960 Very Rare Anomalous Chondrite
NWA 960 Very Rare Anomalous Chondrite 400X I
(c) 2012 Tom Phillips - All Rights Reserved
NWA 960 Very Rare Anomalous Chondrite 400X II
(c) 2012 Tom Phillips - All Rights Reserved
NWA 960 is a very Rare Anomalous Chondrite. This thin section micrograph was taken in cross-polarized light with the addition of a 1/4 wave retardation filter at a magnification of 400X.
It should be noted that these images are of an interesting inclusion and are not typical of the primary material in this meteorite.

To learn more about NWA 960 please see the MetBull entry:
http://www.lpi.usra.edu/meteor/metbull.php?sea=NWA+960&sfor=names&ants=&falls=&valids=&stype=contains&lrec=50&map=ge&browse=&country=All&srt=name&categ=All&mblist=All&rect=&phot=&snew=0&pnt=Normal%20table&code=31971

Wednesday 1 February 2012

Terrestrial Basalt Thin Section Art

Terrestrial Basalt 760x (click on image to enlarge)
(c) Tom Phillips -All Rights Reserved
Terrestrial Basalt 760x
(c) Tom Phillips -All Rights Reserved
Terrestrial Basalt 760x
(c) Tom Phillips -All Rights Reserved