Tuesday, March 8, 2016

Re: [Geology2] Looking for moral support for specimen I.D.



Hi Mike,

Thanks for the added information. I need to ask a couple more questions:

1. Have you done a streak test?
2. Where does this specimen sit on Moh's scale?


I would ask for a closer look at the crystalline formation of this rock, but I know that's impossible. However, I'm glad you had the rock cut so we could see its innards. What has grabbed my attention, most of all, are the dykes within  the rock. There are meteorites that express dykes, but usually they contain shocked material in the core of the dyke with an outer layer of less refined shocked material.

I truly believe that chemical analysis of that rock will explain its origin; all that we will do here is to form a serious, wild ass guess (my biology teacher called that a SWAG) and grapple with certain elements of this rock.  However, I do want to throw my hat into the ring and will continue to try and decipher this mystery.

Has anyone suggested that the rock is granite? I know that granite occurs in Ohio and that this rock could have been plucked and carried by ice in the Pleistocene. The magnetic aspect of the rock could be from the inclusion of hematite or magnetite. But, this is not my final decision; I am merely thinking out loud.

An aside to other group members: come on, folks. Lend some help here.

Lin



On Mon, Mar 7, 2016 at 2:48 PM, Michael Swigart mcswigart@yahoo.com [geology2] <geology2@yahoogroups.com> wrote:
 
[Attachment(s) from Michael Swigart included below]

Hello, Lin.  
In response to your questions:
1. 6" x 4" x 2"--about half the size of a standard brick
2. It's original weight was approximately 2.63 pounds--it has since been cut and sectioned (see attached photos).
It feels denser than comparably-sized rocks of various compositions.
3. It attracts "rare earth" magnets (see photos) and will set off a metal detector.
4. No "pores," just "pits" where material has been eroded away on the top and sides, where the fusion crust would have been thinnest or non-existent.
5. There is no oxidation/rust because this is not an iron meteorite.  My personal theory is that this is an achondrite, probably a eucrite, with intrusive veins of a darker, more crystalline substance, probably a pyroxene, possibly enstatite. The only way to be certain is to have it analyzed in a lab, to determine its elemental/chemical composition precisely.

 I know that what I'm claiming here sounds too preposterous to believe, but I've been studying this rock for nearly 6 years and I believe that it, like a very few other known meteorites, is the result of a collision between two objects in different stages of formation.

I've approached "experts" with this specimen, both in person and through the Internet, but the only consistent answers I get are when they're physically standing next to each other.  I have had people try to convince me, sometimes after having seen only one or two photos (their choice, not mine), that the rock is: slag, magnetite, hematite, basalt, greenstone, metabasite, "some kind of igneous," "some kind of metamorphic," and, my personal favorite, an "eroded river cobble."  I've even had two museum curators, at two different museums, try to convince me that the melting was caused by the pressure of the glacier as it passed over. However, by their own admissions, both knew meteorites only through the labels on the samples on display.

I hope this all helps, even as it complicates matters.
Cheers!
Mike



On Sunday, March 6, 2016 8:31 PM, "Lin Kerns linkerns@gmail.com [geology2]" <geology2@yahoogroups.com> wrote:


 
Hi Mike,

Thanks for submitting this conundrum for us to decipher. However, I do have a few questions to ask before suggesting anything further.

1.  Can you give a general width x length?
2.  How much does the specimen weigh? Does it feel "dense?"
3.  Is it magnetic?
4.  Are there any "pores" on the skin of its surface?
5.  Are there any areas of oxidation?

If you can supply those answers, then those clues might help us further identify what this object actually is?

Thanks,

Lin

PS  Lovecraft is a favorite author of mine, as well. He still gives me the creeps and I like it.







On Sun, Mar 6, 2016 at 3:18 PM, mcswigart@yahoo.com [geology2] <geology2@yahoogroups.com> wrote:
 
[Attachment(s) from mcswigart@yahoo.com included below]
Hello! My name is Mike. Since this is my first group communication, I thought it would be best to give you background info, geology-wise.
I am a 61-year-old Ohio native, who first learned about rocks from those left behind in the moraines and outwash after the final Pleistocene ice regression. The land where I grew up (and which I now own), in rural Miami County, was scraped down to the Silurian bedrock by at least 3 major glaciations before being covered by the debris fallen from the melting ice and wind-blown deposits.
Over more than 50 years of walking hundreds of acres of this farmland, searching primarily for Native American artifacts, I've seen and collected many unusual specimens from this "second-hand" geology. Most of them, I've been able to identify used printed resources and knowledge learned in my college geology courses. For one, however, it has taken years of poking around websites before finding the right search terms to explain the surface features of this unusual, perhaps unique, specimen. (As for the internal composition, I have a hypothesis, but need lab proof.)
I offer the attached photos for your perusal, but would first like to quote from H.P. Lovecraft, one of my favorite authors: "I am disillusioned enough to know that no man's opinion on any subject is worth a damn unless backed up with enough genuine information to make him really know what he's talking about."
Therefore, I would like to ask you to do a little reading to refresh your memory about or introduce you to the topic by typing this phrase --"shield"-type oriented meteorite -- into your search engine. Alternatively, you can go directly to www.meteorites.com.au/odds&ends/oriented.html for a very clear explanation and examples of these rare rocks.
When you view my photos, keep in mind the fact that, if this is not a meteorite, then it had to have come from some hitherto unknown volcanic area between western Ohio and Hudson Bay, Canada, maintaining its integrity as it traveled hundreds of miles at the base of a glacier.
If you have any alternative suggestions, please keep in mind the Lovecraft quote above and be prepared to provide your support.
Thank you for your time.
Mike Swigart



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Posted by: Lin Kerns <linkerns@gmail.com>



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