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Post Info TOPIC: Ste. Marguerite meteorite
Blobrana


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RE: Ste. Marguerite meteorite
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This meteorite was found June 9, 1962 at 9h30mn in a field of potatoes, called" In Bonduel ", located at the corner of County Road 308 and Road Komen Lille, the entrance to the village of Sainte-Marguerite (common Komen) map 1/20000, IGN sheet Lille, numbers 1-2, contact: 647.7 / 339. The field is visited daily by the owner, we can locate the drop between Friday, June 8, 17h30mn and timing of discovery. The fireball was at the bottom of an elongated hole, 65cm long, 45cm wide and 47cm deep. The direction of elongation axis indicates a fall North West South West and the inclination of the settlement of the front wall of the hole, a drop angle of 60-70°. 
On entering the ground, the meteorite is fragmented into six pieces that are juxtaposed, restore its original appearance is vaguely circular, irregular (27x37cm wide and 7 to 10cm thick) and is reminiscent of a round bread flattened base and back domed. Shows the leading edge of a bead of melt 1 to 2mm wide. A fusion crust of 0.6 to 1.2 mm thick, black colour, covering the entire surface, and the inner face is finely bulbous, while on the upper side of the light radiating streaks can be seen from the center of the dome towards the edges.

Source (French)



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Blobrana


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Phosphates also have high U/Pb ratios and these were analyzed by Göpel et al. (1994) to obtain high precision ages of a variety of equilibrated (i.e., petrologic classes 4-6) ordinary chondrites, whose ages range from 4.563 to 4.502 Ga. The phosphates are thought to have formed during metamorphism, thus these ages represent the age of metamorphism of these meteorites. The oldest of these meteorites was H4 chondrite Ste. Marguerite. Bouvier et al. (2007) subsequently reported a Pb-Pb isochron age of 4562.7 Ma, in excellent agreement with the age determined by Göpel et al. (1994). The age of CAI's from CV3 meteorites thus seems 3 Ma older than the oldest precise ages obtained on ordinary chondrites. No attempt has been made at high precision dating of CI chondrites, as they are too fine-grained to separate phases.
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The oldest measured chondrite, Ste. Marguerite (H4), has an absolute age of 4.563 ± 0.001 b.y., an 26Al age of 5.6 ± 0.4 m.y. after CAIs, and a 182Hf age of 4 ± 2 m.y.
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Blobrana


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The Ste. Marguerite (H4) meteorite fell in Nord-Pas-de-Calais, France, on the 8th June, 1962.
A total mass of 4.96 kg was recovered.

50° 46'N, 3° 0'E 



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