An Article In Meteorite-Times Magazine
by Robert Verish

Another Buck Mountains (L6)

An Arizona "find" that was bought at the 2007 Tucson Show just got classified?


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While at the Tucson Show this past February, I came across this Arizona meteorite that was for sale. It was a 75 gram chondritic stone that was found by John Wolfe the previous year in the Buck Mountain Wash area of Mohave County. It was actually two finds by John - a nearly whole individual and a smaller fragment - two fragments that were separated by ~50 feet. But John found that the smaller fragment could be fit back onto the larger piece - making it a complete individual, which makes these two fragments "physically-paired".

What I found interesting was that, although these two fragments were separated by only a few feet, the patina on the exterior of the smaller fragment was a much darker-color than the patina on the larger fragment. The best explanation that I could come up with was that the weathering environment was somehow different for each of these two fragments. To me, these fragments were a very good example of how "micro-environments" could produce localized conditions that would result in variable weathering grades in a meteorite.

So, I bought this meteorite and took it home to be classified.

The above image and the next 3 images were taken by this author at the 2007 Tucson Show.

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"Click" on the above image of a Buck Mountains (L6) for a Close-Up view!!

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"Click" on the above image of a Buck Mountains (L6) for a Close-Up view!!

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"Click" on the above image of a Buck Mountains (L6) for a Close-Up view!!

The following images in this gallery show the specimen after it was cut.
(In the images below, the meteorite has been placed next to its label.)

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"Click" on the above image of a Buck Mountains (L6) for a Close-Up view!!

The above image shows that the cut appears to have revealed an interior that is much less weathered than would have been expected, considering the degree of weathering of the exterior. But the cut reveals even more about this find. The cut suggests that this meteorite could be an L-chondrite. (This is supported by the observation that a magnet has only a weak attraction and a metal detector has a poor response to this stone.) And if this find were to be classified as an L-chondrite, it's also possible that it may be paired to one of the existing L6 meteorites that have already been found within the Franconia strewn field.
So now, my main interest in this find is to get it turned-in for classification. And as luck would have it, it got classified in record time.
See classification below.

In the image, below, is depicted a close-up of this cut surface.

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"Click" on the above image of a Buck Mountains (L6) for a Close-Up view!!

What we now know about John Wolfe's meteorite from this cut surface:

The above close-up image reveals an interior that has a uniformly orange-colored groundmass, exhibiting a mottled appearance because of tarnished sulfide grains and metal grains that have partially oxidized, This oxide has locally stained the matrix with a rusty color producing the "orange-colored" appearance. There is no demarcation between the exterior and the interior, because there is no evidence of a rind, let alone a relict fusion-crust. And the few, larger chondrules that are discernable, are clearly well-equilibrated with the crystalline groundmass, which indicates this stony to be an equilibrated Ordinary Chondrite (OC).

In the image, below, we see the reconstructed stone and how the two fragments fit back together.

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"Click" on the above image of a Buck Mountains (L6) for a Close-Up view!!

The image, below, is the same view as the image above, but it was taken at a different angle.

Click-to-ENLARGE

"Click" on the above image of a Buck Mountains (L6) for a Close-Up view!!

The image, below, is the same view as the image above, but it was taken at a different angle.

Click-to-ENLARGE

"Click" on the above image of a Buck Mountains (L6) for a Close-Up view!!

Here is what we now know about John Wolfe's Buck Mountains meteorite find:


Found:  North of the Buck Mountains in Mohave County, Arizona.
 
Date of find:  2006 December 12 
 
Class: Stone. Chondrite, Ordinary (L6, S3, W2, olivine Fa 24.1 +/-0.5)
 
TKW:  Approx. recovered weight:  75.4 grams  

Finder:  One whole stone (in 2 pieces) of TKW = 75.4grams was found by John Wolfe of Iowa.  
 
Specimens:  9.30 grams (type specimen)

Main mass:   with (Verish).
 

With the above information it is now possible to request a "provisional name & number" from the Nomenclature Committee of the Meteoritical Society.

Postscript: I've been asked why I use the phrase "Buck Mountains (L6)" for this stone. The short answer is, "sounds better that Franconia (L6)". But a better answer requires a better explanation.
First, do you remember "Gold Basin (L6)"?
Yes, I know that's ancient history, but if you remember, when researchers tried to get names approved for those "Gold Basin Area" meteorites that were classified as "L6", they were told to just call them "Gold Basin (L6)". Well, given that precedent, it seemed prudent to use that same naming convention for classified stones from the Buck Mountains area.

This stone needed a name, because when it was purchased it was labeled as "Buck Mountain Wash 002". But that provisional name was not offically approved, so I had to change the label. Maybe the original label was a typographical error, and should have been titled "Buck Mountains 002", because both this stone and the Buck Mountains 002 stone were found by John Wolfe. And since both of these finds are now classified as "L6", that would make sense to give it that name, as well, but then there's the problem that these two stones have not been shown to be paired. One problem is that the olivine Fa% do not overlap. In fact, based on these same numbers, this stone is a closer match to the Palo Verde Mine (L6) classification. But since the last L6 was named "Buck Mountains 003" (and it is NOT paired to BM 002, personal communication with classifier) it is very likely this numbering sequence will be continued. But predicting what the name might be isn't easy, and besides, I've learned that it's not very popular to number meteorites.
So that's why I call this classified find a "Buck Mountains (L6)" meteorite.

If you have any information relating to Buck Mountains (L6) meteorites, please contact me by email: Bolide*chaser

REFERENCES:

Here is a list of the official classifications in the Franconia strewn field area. As you can see, there are 3 L6 chondrites listed that are not paired.

11 meteorites found within 10 km of Warm Springs Wilderness. Name Status Fall Year Place Type Mass MetBull Ant Catalogs GoogleEarth
••Map all ↓ Notes
Buck Mountain Wash Official 2004 Arizona, USA H3-5 798 g 89 7.9 km SE of Warm Springs Wilderness
Buck Mountains 001 Official 2004 Arizona, USA H6 50 g 90 6.6 km SE of Warm Springs Wilderness
Buck Mountains 002 Official 2004 Arizona, USA L6 18.4 g 90 8.5 km SE of Warm Springs Wilderness
Buck Mountains 003 Official 2005 Arizona, USA L6 34.2 kg 91 6.5 km SE of Warm Springs Wilderness
Franconia Official 2002 Arizona, USA H5 100 kg 88 8.3 km S of Warm Springs Wilderness
Palo Verde Mine Official 2004 Arizona, USA L6 9.16 kg 89 9.7 km SE of Warm Springs Wilderness
Sacramento Wash 001 Official 2003 Arizona, USA H4 98.9 g 90 3.7 km SE of Warm Springs Wilderness
Sacramento Wash 002 Official 2004 Arizona, USA H4 893 g 90 3.7 km SE of Warm Springs Wilderness
Sacramento Wash 003 Official 2004 Arizona, USA H4 89.2 g 90 3.5 km SE of Warm Springs Wilderness
Sacramento Wash 004 Official 2004 Arizona, USA H5 28.6 g 90 4.6 km SE of Warm Springs Wilderness
Warm Springs Wilderness Official 2003 Arizona, USA H4-6 156.9 g 90 Center of Search

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Google Web Search Results 1 - 3 of about 10 for Buck Mountain meteorite. (0.05 seconds) 

Erwin F. Lange Endowment

We have recently classified the following meteorites: Buck Mountain Wash; Buck Mountains 001, 002, and 003; Palo Verde Mine; ...
meteorites.pdx.edu/lange.htm - 10k - Cached -

Arizona Meteorite Collection

Featured here are the Arizona meteorites in my collection updated 2/08/07 ... Buck Mountain Wash (H5) 29g full slice. Buck Mountain 002 (L6) 9g indiviual ...
www.meteoritebiz.com/azcollection.htm - 6k - Cached -

Forum discussion on variety of Franconia Area meteorites

Nugget Shooter Forums _ Meteorite Hunting and Collecting Forum _ Other ... Next, and not necessarily in chronological order is Buck Mountain Wash . ...
www.nuggetshooter.ipbhost.com/index.php?act=Print&client=printer&f=4&t=6399 - 57k - Cached -


My previous articles can be found *HERE*

For for more information, please contact me by email: Bolide*chaser