[meteorite-list] Question about NWA 869
From: MexicoDoug <mexicodoug_at_meteoritecentral.com>
Date: Fri, 4 Nov 2011 03:49:36 -0400 (EDT) Message-ID: <8CE68DD6EE3B4A7-2840-3EDE1_at_webmail-d132.sysops.aol.com> NWA 869 represents an L chondritic regolith breccia containing preirradiated components. The meteoroid had an initial radius of about 2 m with a mass of about 110 metric tons. The transit time to Earth was about 4-5 Ma. Large variations of shielding depths between samples indicate that break-up of the meteoroid must have occured high in atmosphere. This would also explain the large inferred ablation loss, which is typical for large chondrite showers. Ref: "The L3-6 Regolith Breccia Northwest Africa 869: Petrology, Noble Gases, and Cosmogenic Radionuclides" Metzler, K.; Ott, U.; Welten, K. C.; Caffee, M. W.; Franke, L. 39th Lunar and Planetary Science Conference, (Lunar and Planetary Science XXXIX), held March 10-14, 2008 in League City, Texas. LPI Contribution No. 1391., p.1120 Publication Date: 03/2008 http://www.lpi.usra.edu/meetings/lpsc2008/pdf/1120.pdf -----Original Message----- From: Melanie Matthews <miss_meteorite at yahoo.ca> To: MeteoriteList <meteorite-list at meteoritecentral.com> Sent: Fri, Nov 4, 2011 2:10 am Subject: [meteorite-list] Question about NWA 869 Hi list, Are there any estimates in how long ago this wonderful meteorite fell to Earth, and how large it might have been before it entered the atmosphere? It must have been a massive meteoroid, much larger than the one that produced the Buzzard Coulees. ? ----------- -Melanie "MetMel" - avid meteorite collector/enthusiast from Canada! IMCA#: 2975 eBay: metmel2775 I eat, sleep and breath meteorites 24/7. ______________________________________________ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list at meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list Received on Fri 04 Nov 2011 03:49:36 AM PDT |
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