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Elmore County ~ Iron, IAB-MG: A Classification Story


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I thought it might be interesting to share here the journey of helping my friend Fred get an iron meteorite classified.  I posted this on another forum, but thought some folks here may get something out of it as well.

Items quoted in italics are direct excerpts from emails written by the parties as indicated.

_____________________________________________________

In 2013, with the assistance of Geoff Notkin, Fred's iron was sent to Dr. Laurence Garvie at ASU for analysis.  I don't have an exact date, but as is often the case with meteorites it can take a long time to have them studied.  A year passed, and in May of 2014 we all followed up with ASU to see if they had time to look at the iron yet.  By the end of June 2014, Dr. Garvie informed us that he had sent a small piece to Dr. John Wasson at UCLA for INAA analysis.  Dr. Wasson only runs a few INAA studies a year, and each study takes about 4 four months to complete (two irradiation sessions and two weeks data acquisition).

In July of 2014 Dr. Garvie wrote that the INAA run was scheduled for August, and that he had "...etched a small end piece and am now not so sure that it looks like a Campo. I’ll see if I can snap a picture soon and send it out. I may even be seeing a heat affected rim around one edge -which would imply the stone is fairly fresh. If I use my imagination, I even think I see some patches of fusion crust."

Unfortunately, Dr. Wasson receives several "new irons" every year that turn out to not be so new, but rather someone trying to pass something off as a new discovery.  By November of 2015 the iron had still not been analyzed, so I contacted Dr. Garvie and asked if he could return the iron so that we could pursue other avenues to have it studied.

The iron was sent back to me in December 2015.  I reached out directly to Dr. Wasson and learned that he had actually analyzed the first sample and had asked Dr. Garvie for a second sample, which was sent to him by ASU at the same time the entire mass was sent back to me.  Dr. Wasson had other irons with priority for his INAA runs, but he informed me that he did intend to further analyze the samples in March or April of 2016.  He also asked Fred to provide the accounts of the iron's discovery, it's total mass, and other pertinent information.

On May 23, 2016, Dr. Wasson was finilizing the INAA data acquisition and the results were indicating similar composition to Campo del Cielo, however, he noted that there were "...hints of small differences" and asked me to send one more sample for a follow up analysis to be performed in the next INAA run set for spring of 2017.  I sent the mass to Montana Meteorite Laboratory to have a sample of clean iron with no inclusions or weathering products prepared for Dr. Wasson.  We also had several slices of the meteorite prepared, as well as a type specimen to be donated upon conclusion of the classification process (a picture of these pieces is included at the bottom of this post).  Below is a picture of the final sample sent to Dr. Wasson for analysis:

20170314_111344.jpg?width=721

On May 25, 2017 I received the following email from Dr. Wasson:

"Michael

I have the data.  I haven’t yet fully digested it, but I will try to do that on the weekend and then prepare a note for you and Fred.

The bad news is that, like the first data, the composition seems to fall within the range of Campo irons.

This means it will take additional work to show that it is worthy of a name.

I’ll write you soon.

John"

The results of the INAA analysis are presented below:

 

Cr

Co

Ni

Cu

Ga

As

Ru

Sb

W

Re

Os

Ir

Pt

Au

 

µg/g

mg/g

mg/g

µg/g

µg/g

µg/g

µg/g

ng/g

µg/g

ng/g

µg/g

µg/g

µg/g

µg/g

Bart iron

11

4.49

65.3

157

88.5

11.0

6.6

255

1.22

446

4.9

4.13

7.5

1.468

Bart iron

25

4.46

67.4

111

90.7

11.1

6.8

339

1.28

382

5.1

4.08

8.8

1.446

Bart iron

18

4.48

66.4

134

89.6

11.0

6.7

297

1.25

414

5.0

4.10

8.2

1.457

Slide1.JPG?width=721

While these results also showed a strong similarity to the Campo iron, Fred's account of this iron's discovery was reasonable and substantiated by other parties, so the wheels of science ground on.

I was contacted again by Dr. Wasson a year later on June 18, 2018.  He was preparing a paper on iron meteorites with similar compositions to Campo del Cielo and he was including Fred's iron in his study.  In order to be included in scientific literature the iron must be recognized with an official name in the MetBull.

I received an email from Jérôme Gattacceca, Editor of the Meteoritical Bulletin of the Meteoritical Cosiety, on June 21, 2018, informing me that Fred's iron was before the Nomenclature Committee and they were considering a Nova number for it unless we could provide a precise account on how the meteorite was found.  I sent Mr. Gattacceca Fred's story of how he came to be in possession of the iron and assured him that a type specimen would be donated to UCLA.  On June 22nd the vote was opened by the Nomenclature Committee to decide between a Nova number or Elmore County.  On June 30, 2018, the meteorite was approved and entered in MetBull 107 with its official name: Elmore County https://www.lpi.usra.edu/meteor/metbull.php?code=67626.

On July 2, 2018 I hand delivered the type specimen to Dr. Wasson at his office at UCLA.

BartIron01.JPG

signal20170313230348.jpg

Edited by Mikestang
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Thanks for the relating the journey to us. It took almost 70 -80 years from the time it was found until it was classified. That is a really loooong journey...

 

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Glad to see that both Fred and the specimen endured, and survived the classification process.  Though it takes years unless you have juice, it is the right thing to do, and encourages  some of us to submit cold finds that we are sitting on, even though that process can be quite trying.  I would like to see investment and creation of a non-university, private  lab, staffed by a salaried meteoriticist, with a "Dean Bessey" turn-around time ( us old guys remember).  I am sure that the volume that would flow to the lab would keep the cost to the submitters low, while paying the staff much better than any university, without cutting into the action of the usual sacred cows that seem to gobble up the bulk of researcher's time and budgets at the usual venues.  Let's take the steps to foster meteorite science in our own country, and expand our efforts to bring American finds out of the shadows, and get them classified.  

Congrats to Fred, and big thanks to Michael and all that made this classification possible.

    Ben

Edited by Regmaglitch
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