by Robert Verish

Some Recently Found Meteorites

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The title of this column, "Bob's Findings", suggests that the subject matter of my articles should be about my field excursions. And since most of my field work is conducted in the Mojave Desert, it has been a concern of mine that my articles would be too parochial. Meaning that the subject matter would be too Southwestern U.S.-desert-centered to be of interest to the majority of our world-wide readership. So, the inclusion of the recently found German meteorite, the Neuschwanstein stone, is a conscious attempt to make this months article more "international".

In case you haven't heard about this exciting new find, I have listed a number of web pages at the end of this article that offers what information is available about this meteorite. Since this is a newly found meteorite, there is only limited information about its recovery. It hasn't been classified, yet, but it is clearly a stone, and most likely a chondrite. And, in case you have read about this stone, but would like to see some "Close-up" images, "click" on the following URLs (these ".jpg" images are large file-sized, so please allow time for them to download):

http://berlinadmin.dlr.de/HofW/2002/145/Meteorit.jpg

http://berlinadmin.dlr.de/HofW/2002/145/Meteorit_Vergleich.jpg

http://berlinadmin.dlr.de/HofW/2002/145/Meteorit_Team.jpg

Now that you've had a good look at the "Neuschwanstein stone", you are probably asking, "So what is the story about the stones whose images are depicted in this article?". Or, "That's not the Neuschwanstein stone! What meteorite is that?"

Good questions. The images in this article are of two Mojave Desert meteorites, even MORE recently found than the Neuschwanstein stone! And like that German meteorite, these stones haven't been classified, yet, either. And like the German meteorite, these stones appear to be "freshly-fallen", but upon closer examination, these stones display various grades of weathering. This article is a comparison of the external features of these two, variously weathered Mojave Desert meteorites to the Neuschwanstein stone.

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This 200 gram chondritic stone was found by an 80 year old man who lives alone on a ranch in the middle of the Mojave Desert. It was brought to me for identification and examination by a friend of his. We had arranged to meet at a Denny's restaurant. All of the images of this stone were taken in that restaurant. I had to make do with what light was available, but for the most part it is indirect, morning sunlight along with a little incandescent lighting.

When presented to me for examination, this stone was already in two pieces, a main mass and a much smaller, flat-shaped fragment. The 30 gram fragment easily re-attached to one end of this oblong stone. But this fragment had on its top side a dime-sized spot where the fusion crust appeared to be crushed. Prior to this fragment being broken off, this stone was obviously whole with 100% fusion crust. This crust exhibited contraction cracks over the majority of its surface, which were filled-in (in most of the cracks) with a light-colored, fine-grained silt that stood in stark contrast to the nearly black exterior. There was a hint of smeared clay where the stone May have been resting on the ground at one time. Other than those streaks of clay and the cleaved 30 gram fragment, the exterior was unflawed.

 

Separating the "cleaved" portion of the stone from the main mass reveals an unweathered interior. I call this "cleaved", because there is evidence that this stone was struck with a hammer, possibly in order to reveal its interior. This has yet to be confirmed, but this exposed surface May have been exposed to the elements for week to months. There is ample evidence that the fusion crust, the contraction cracks and the area immediately underneath have experienced more weathering; possibly several years more than the exposed surface. Unless the rusty metal grains directly underneath the contraction cracks are used in the determination of weathering grade, this stone will probably be deemed a "W1".

 

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This cleaved fragment has become the "type specimen" for this meteorite. A sample from this fragment was taken to be thin-sectioned and micro-probed in order to determine its classification. If you "Click" on the this image and allow time for this large file to download, the close-up image will reveal a relatively fresh broken surface, exhibiting untarnished sulfide grains, a few metal grains which have stained the matrix with a rusty halo, and scant few chondrules that are clearly equilibrated with the crystalline ground mass. This indicates the stone to be a common Ordinary Chondrite (OC).

 

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In this image the marks on the fusion crust indicate the bottom side of the stone where it had rested on the ground in a clay-rich soil.

As I examined this interestingly shaped stone, I wondered how the stone survived its fall intact?
And other questions came to mind:
How long did this stone sit on the ground until it was found?
How can this stone appear so fresh, yet the recently fallen Neuschwanstein stone already look so weathered?
Being a complete individual with 100% fusion crust, and NO secondary fusion crust, (meaning, there was no evidence of a fragmentation event) is there less of a chance of finding other stones from this fall? Or was this a single-stone fall?
Being so fresh, how did this stone get to the ground without a bright fireball and sonic boom being witnessed in the recent past?
Did this stone fall during a CLOUDY DAY?
Is this stone large enough to produce a sonic boom?
What size/shape does a stone have to be, before the deceleration of its fall to subsonic velocity produces a sonic boom?
Since the October 1997 Bolide, has there been any other fireballs + sonic booms reported in the Mojave Desert area?
And still more questions...

 

This end of the stone shows where it was struck when the fragment was "cleaved".

The find location has yet to be divulged, but I have been promised that it will be, "eventually". And I have no other recovery information. But, when it is divulged, I will be making a very concerted effort to authenticate the find location. Meaning that I will be searching for supporting evidence, such as another fragment from this fall. With a little bit of luck, one of my future articles might be a report on how I linked this stone to a witnessed fireball!

 

Because of the less than adequate lighting conditions inside the Denny's restaurant, several of the images were unsatisfactory. Nevertheless, I would like to thank Denny's for the use of their restaurant for the examination and imaging of this remarkable new meteorite find. (If you have a find that you would like to have authenticated, you can contact me, and I can make myself available at any Denny's restaurant in the Mojave Desert;-)

 

-- BELOW is the 2nd MOJAVE DESERT FIND for the MONTH OF AUGUST 2002 --

This image depicts the find local for, what is to the best of my knowledge, the "2nd Mojave Desert meteorite find for the month of August 2002". This local is part of an area that I have been studying for over two years, now. What this means is that, although this particular stone has not been classified, yet, there is a very strong possibility that it can be paired to one of my earlier finds.

 

This image depicts the find as it is being recorded. Even at this point, it is still untouched.
Even before I held the stone, I could see a few rust-colored spots on a black patina and it immediately reminded me of the images of the Newschwanstein stone that I had seen just days earlier. Even then I wondered how long this stone had lain here in the Mojave Desert, yet in this first glance, its appearance was so similar to that freshly found Bavarian stone?

For the purpose of this discussion, let's assume that this stone is paired to my previous finds from this study area, all of which have been classified as "W3". Although some of those finds were made more than two years ago, I was immediately struck by how little difference there was in the weathering of this stone to its sister stones, even though they have the benefit of two years less weathering. Clearly, in this climate, two additional years of weathering upon a "W3" stone will net very little additional change. (At the time that I made that observation, it was in regards to the stones exterior appearance. But I had to remind myself, the "grade" of weathering is dependent upon the condition of the metal and sulfide grains in the interior! So, let's wait until this stone is cut before guessing at a weathering grade.)

 

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The above image depicts the same find "just-plucked" from the sediment within which it had been residing, and weathering.
Now, it's obvious that this stone doesn't have a uniformly crusted exterior. Some of the sides of the stone are smooth with rounded edges, but several sides are uneven with jagged edges. One of the uneven sides is particularly interesting because it is a good example of how secondary fusion crust develops. Clearly this stone has fragmented twice; once while still ablating, and then again, much later, probably upon the ground.

 

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The "ENLARGED" image of this 30.4 gram stone clearly shows the rust-colored spots on the relic fusion crust, which reminded me of the similar weathering features on the recently found "Neuschwanstein stone". Although this stone is 1/60th the size of the "Neuschwanstein stone", both stones have had some of the metal grains closest to their exteriors produce noticeable "rust blisters". The lower left corner of the stone in the image shows that it has had its fusion crust chipped away. This has exposed the interior and weathering has caused crystalline matrix to darken to a rust-color.

 

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This image depicts the stone after it has been cut to remove the type specimen. The interior is deeply and uniformly stained by the oxidation products of the weathered metal and troilite grains. The broken surfaces have facilitated the weathering of this stone. Some of the small voids in the groundmass May have been former metal grains, which have since oxidized. These oxides have since vacated, forming the voids, migrating throughout the interior of the stone, and staining the crystalline matrix and chondrules. Regardless of the well-preserved exterior, this find will probably be deemed a moderate- to well-weathered, chondritic stone. Regardless of this stones exterior similarity to the "Neuschwanstein stone", this Mojave Desert find must have a greater terrestrial age. This should be expected given the dissimilar environments of the find locations.
All of the meteorites shown in this article are still pending classification.

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

REFERENCES:

Searched the web for Neuschwanstein meteorite. Results 1 - 10 of about 93.

[meteorite-list] NEW ! ! ! First found of the Neuschwanstein" ...
Hello list, The first piece is 1750g big !

http://www.pairlist.net/pipermail/meteorite-list/%202002-July/013378.html

[meteorite-list] NEW ! ! ! First found of the Neuschwanstein" ...

http://www.pairlist.net/pipermail/meteorite-list/%202002-July/013372.html

[meteorite-list] NEW ! ! ! First found of the Neuschwanstein" Meteorite. ... !
Date: Tue, 30 Jul 2002 07:36:47 -0700. ...

http://www.mail-archive.com/meteorite-list@meteoritecentral.com/msg05565.html

RE: [meteorite-list] Breaking News: The "Neuschwanstein" ...
First found of the Neuschwanstein" Meteorite, Thomas Kurtz:

http://www.mail-archive.com/meteorite-list@meteoritecentral.com/msg05575.html

Dutch Meteor Society: Bright Fireball over Bavaria/Germany ... July 14!!!)
Photo's of the Meteorite of Neuschwanstein (communicated by Marco Langbroek).

http://www.xs4all.nl/~dmsweb/fireballs/20020406_fireball.html

Am 6 April haben 6 Hobby-Astronomen von der Sternwarte Hannover ... - [Translate this page ]

http://www.stud.fh-hannover.de/~kurtzt/Meteorite/%20Alpensuche/Alpensuche.htm

GERMAN METEORITES. *FALL/FUND. ORT, LAND, TYP, GEW. [kg], BML [g]. *928, AUGSBURG, Bayern, April 2002, NEUSCHWANSTEIN, Bayern... - [Translate this page ]

http://home.t-online.de/home/Bartoschewitz.Meteorite-Lab/%20deutsche.htm

DLR - Das Europäische Feuerkugelnetz - [Translate this page ]...

http://solarsystem.dlr.de/PG/EN/index.shtml

Nederlandse meteorieten - [Translate this page ]...

http://berlinadmin.dlr.de/HofW/2002/145/