[meteorite-list] NEW Ocate, NM Iron Classification
From: Greg Hupe <gmhupe_at_meteoritecentral.com>
Date: Tue, 26 May 2009 20:20:35 -0400 Message-ID: <A71D827E1D0742E58FF2D5C6271780FE_at_Gregor> Hello Rob, Thank you for your email. Good question. Between the science done, finder's statement and visually inspected by many people who have seen a lot of Canyon Diablo, there is not a chance of a pairing. Best regards, Greg ==================== Greg Hupe The Hupe Collection NaturesVault (eBay) gmhupe at htn.net www.LunarRock.com IMCA 3163 ==================== Click here for my current eBay auctions: http://search.ebay.com/_W0QQsassZnaturesvault ----- Original Message ----- From: "Matson, Robert D." <ROBERT.D.MATSON at saic.com> To: "Greg Hupe" <gmhupe at htn.net>; <meteorite-list at meteoritecentral.com> Sent: Tuesday, May 26, 2009 7:49 PM Subject: RE: NEW Ocate, NM Iron Classification > Hi Greg, > > How sure is UAb that Ocate isn't paired to Canyon Diablo? Here's a > comparison of trace elements (units are mg/g for Ni & Co, micrograms/gram > for all others): > > Elem. Ocate, NM Canyon Diablo Diff. Sigma > ----- -------------- --------------- ----- ----- > Ni 69.9 +/- 0.5 69.2 +/- 1.7 0.7 < 1 > Co 0.466 +/- 0.004 0.468 +/- 0.015 0.002 << 1 > Ga 71.9 +/- 0.3 83.8 +/- 3.4 11.9 3.2 > Ge 271 +/- 6 322 +/- 19 51 2.0 > Ir 2.25 +/- 0.04 2.17 +/- 0.07 0.08 < 1 > Au 1.60 +/- 0.03 1.57 +/- 0.11 0.03 << 1 > As 15.2 +/- 0.3 12.7 +/- 0.7 2.5 2.5 > Cu 119 +/- 11 148 +/- 6 29 1.7 > W 0.87 +/- 0.08 0.99 +/- .129 0.12 < 1 > Re 0.22 +/- 0.02 0.228 +/- 0.027 0.008 << 1 > > The most significant differences are gallium (more than 3-sigma different) > and germanium (2-sigma). (The 2.5-sigma difference on arsenic may not be > as significant since the 1-sigma measurement error is greater than 5%; > similarly, copper's measurement uncertainty is greater than 9%.) > > --Rob > > -----Original Message----- > From: meteorite-list-bounces at meteoritecentral.com > [mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Greg > Hupe > Sent: Tuesday, May 26, 2009 3:18 PM > To: meteorite-list at meteoritecentral.com > Subject: [meteorite-list] NEW Ocate, NM Iron Classification & Specimens - > AD > > Dear List Members, > > I would like to announce a newly-approved iron meteorite found in New > Mexico in 1986 and has just been approved. It is a IAB-MG (Main Group), > coarse ochtahedrite and is named "Ocate" after the nearest town to where > it was found. It will be in the online database soon and will be published > in MB96 (Sept, issue MaPS). It wasn't until 2008 that they finder > approached me with the single 6.4kg stone that the classification process > began. I went to the find site last fall with the person who found it to > take GPS coordinates, photograph the area and to hunt for more if there > were any to be found. We didn't have much time to hunt at that time so we > did not find any others. > > Here are a couple of links to give you an idea of how nice Ocate is (see > all available specimens below classification below). This was cut and > prepared by one of the best meteorite craftsman in the business! > > Polished and etched face of a 314g complete slice: > http://www.lunarrock.com/ocate/specimens/dsc00002.jpg > Ocate, New Mexico sign: > http://www.lunarrock.com/ocate/OcateSign.jpg > The find site of the 6.4kg Ocate iron: > http://www.lunarrock.com/ocate/findsite.jpg > > Getting to the find site is treacherous and a 4-wheel drive vehicle with > high clearance is required! It took us about three hours after leaving the > paved road to get to the site up the mountain on a road that was more like > a crater-ridden trail with large boulders in most places and swampy mud in > others. To successfully hunt the site would require camping for a week, > there is no way to drive up and down the mountain each day and get enough > hunting hours in to make it worthwhile. There are also lots of elk hunters > during hunting season so anyone who wants to give it a go, be careful! > > Submitted and approved classification for "Ocate": > Ocate > 36? 17.72' N, 105? 2.90' W > > Mora County, New Mexico > > Find: 1986 > > Iron (IAB-MG), coarse octahedrite > > > > History: This single 6.4kg mass was found by a local New Mexico hunter in > 1986. Knowing it was different from the surrounding rocks and had an odd > appearance (the face of a bear), the hunter took it home and set it aside > with an odd assortment of 'collectibles' while hunting and mountaineering > over decades in the New Mexico area. The owner contacted G. Hupe in May > 2008 for verification of the find, which was confirmed by study of the > type sample at the University of Alberta. > > Physical characteristics: A single stone weighing 6402 grams with > virtually no apparent fusion crust, yet also lacking progressed > terrestrial alteration, which contributes towards its dark brown metallic > appearance with well defined regmaglypts. > > Petrography: (C. Herd, N. Bruemmer, UAb) A 5 x 7 cm polished and etched > slab reveals Widmanst?tten pattern with an average bandwidth of 1.4 ? 0.2 > mm, few areas of plessite, and numerous inclusions. A 1 cm ellipsoidal > graphite nodule and several smaller inclusions of graphite, troilite and > schreibersite are associated with polygonal kamacite on one portion of the > slab. Smaller, mm-scale elongate inclusions of troilite are oriented > parallel to kamacite lamellae where the Widmanst?tten is better developed. > Terrestrial oxides decorate fractures within a few mm of the exterior > surface. > > Geochemistry: Bulk Composition: INAA data (J. Duke, UAb): Ni = 6.99 ? 0.05 > wt%, Co = 0.466 ? 0.004 wt%, Ga = 71.9 ? 0.3 ?g/g, Ge = 271 ? 6 ?g/g, Ir = > 2.25 ? 0.04 ?g/g, Au = 1.60 ? 0.03 ?g/g, As = 15.2 ? 0.3 ?g/g, Cu = 119 ? > 11 ?g/g, W = 0.87 ? 0.08 ?g/g, Re = 0.22 ? 0.02 ?g/g (uncertainties 1s, > 68% confidence level). > > Classification: Iron meteorite, IAB main group, coarse octahedrite, > minimal shock, minimal weathering. > Received on Tue 26 May 2009 08:20:35 PM PDT |
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