[meteorite-list] Osceola

From: MexicoDoug <mexicodoug_at_meteoritecentral.com>
Date: Sun, 3 Apr 2016 14:32:55 -0400
Message-ID: <153dd6631a9-17a8-b16c_at_webprd-a18.mail.aol.com>

Thanks Rob! Does being there 4 days before the fall figure in anywhere? :-)

Though Larry may not have been first on the field, nor found the first, or for all I know, the last one ... his dedication and larger specimen is a fresh virgin princess IMO! I really hope the temptation to expose the fresh interior never arises.

It would be very instructive to know the weight of the current main mass as found and then as well dried, as I can easily see 100 or more grams of water taken up by it, a real consideration for reporting the weights of most of these stones.

Kindest wishes
Doug


-----Original Message-----
From: Rob Matson via Meteorite-list <meteorite-list at meteoritecentral.com>
To: 'meteorite-list' <meteorite-list at meteoritecentral.com>
Sent: Sat, Apr 2, 2016 4:02 pm
Subject: Re: [meteorite-list] Osceola Meteorite is Official!

Congratulations to Mike, Larry, Laura, Josh and Brendan for their aggressiveness ingetting to the fall location quickly and their persistence in the face of veryunfavorable searching conditions (SWAMP!) It is an impressive feat that anythingwas found at all, even with the nice radar returns.I have one correction: I'm pretty sure Larry was the second on the scene. SteveArnold drove all night from Arkansas to arrive (I believe) the morning afterthe fall -- Monday, January 25. --Rob-----Original Message-----From: Meteorite-list [mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Michael Gilmer via Meteorite-listSent: Saturday, April 02, 2016 11:00 AMTo: Meteorite ListSubject: [meteorite-list] Osceola Meteorite is Official!Osceola meteorite is official, approved by NonCom and entered into theMet Bull today - http://www.lpi.usra.edu/meteor/metbull.php?code=63109Osceola 30?27.16?N, 82?27.25?WFlorida, USAConfirmed fall: 2016 Jan 24Classification: Ordinary chondrite (L6)History: (Mike Hanke
y, Larry Atkins, Laura Atkins, Josh Adkins,Brendan Fallon, Robert Matson, Marc Fries) On Sunday Morning 24January at 10:27 EST (15:27 UTC) a large daytime fireball streakedacross the sky in northern Florida. Over 100 eyewitnesses reported theevent to the American Meteor Society (Event 2016-266), describing awhite sparkling head and plume of white smoke left behind. Fireballresearchers Marc Fries and Rob Matson, found the American MeteorSociety witness trajectory intersected with a group of radar returnsthat appeared shortly after the fall. The radar returns were strong,found at multiple altitudes and located on multiple stations: KJAX,KVAX and KTHL. Larry Atkins was the first on the scene. Mike Hankeyarrived 5 days after the fall with Brendan Fallon and joined Larry andLaura Atkins in the hunt. On the 6th day, Mike Hankey found the firststone at 8.5 g on the eastern edge of the primary radar return. Within2 hours Larry Atkins found the second stone (18.5 g) directly underthe radar. The next day, two more sto
nes were found: a 5.5 g stone byLaura Atkins and a 48.5 g stone by Mike Hankey. Six days later over 2miles away from the first find, an 839 g mass was found by Josh Adkinsand Brendan Fallon. A week after that, Larry Atkins found the laststone, weighing 75.5 g. In total 6 stones were found over a three weekhunting period for a total weight of 990.5 g.Physical characteristics: Thin, well formed shiny fusion crust coversthe exterior of four of the stones, while two of them, the 43 g andthe 839 g are matte black. This is likely due to submersion in wetsand and/or water prior to recovery. Some small rust spots are evidenton some of the stones as well. Small regmaglypts are present on the 43g and the 839 g stones, and the remaining stones are irregularlyshaped with little to no orientation. Some chondrules are visiblethrough the crust. The interior of the meteorites are slightlydarkened due to shock. Shock veins are present, some of which areblack while others are filled with metal, appearing as long "strings"up t
o 3 mm long. Though most of the chondrules have been altered andare not well defined, some rare, large chondrules up to 0.8 mm arepresent.Petrography: Plagioclase grains are up to 100 ?m in size, consistentwith type 6. No maskelynite was found. There are numerouschromite-plagioclase assemblages, consistent with moderately strongshock. Chromite grains are fractured. Troilite is polycrystalline.Metallic copper occurs as 2-?m-thick bands at the metal-troiliteinterface in an opaque assemblage. The chondrules are recrystallizedand poorly defined. The only discernible chondrules are large ones,800-1000 ?m across; these are BO and PO textural types.Geochemistry: Olivine Fa23.7?0.3 (n=21), OrthopyroxeneFs20.2?0.2Wo1.6?0.2 (n=14). Also present are small grains of diopside:Fs7.4 Wo44.9 (n=1). Plagioclase has a mean composition of Ab71.7?1.6Or8.8?2.5 (n=8); the low Na and high K values are a result of shock.Specimens: 21.8 g at UCLA______________________________________________Visit our Facebook page https://www.facebo
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Received on Sun 03 Apr 2016 02:32:55 PM PDT