Carancas is official
Posted January 7th, 2008 by Admin
Jeff wrote >>Just a note: the Nomenclature Committee has officially named the 2007 Peru impactor "Carancas". See the entry at http://tin.er.usgs.gov/meteor/index.php?code=45817
A H chondrite? mmmm many strange, the apparence is many similar to a L or L chondrite
Matteo
Hello Matteo, Jeff G. and List,
That's why I wrote this on Sun Oct 07-2007 with regard to the thin section pictures you can view here (it was Sterling who posted the link) :
http://www.ingemmet.gob.pe/paginas/pl01_quienes_somos.aspx?opcion=320
"... there is a "conglomerate" of what may have been one or several large BO chondrules (chondrule fragments). This causes a bit of a headache because, if this is or was a large BO chondrule, I wouldn't rule out an L chondrite as H chondrites *tend* to have smaller chondrules!"
But I was careful and wrote "H chondrites *tend* to have smaller chondrules". One of my Carancas specimens has a beautiful 0.7 mm chondrule protruding completely from the surrounding matrix - large enough to consider it an L chondrite. But:
Chondrule size is not the only criterion! These Fa and Fs values below definitely place Carancas in the realm of the H chondrites:
Olivine (Fa18.4±0.5) and pyroxene (Fs16.1±0.2)
Some examples with (almost) identical Fa and Fs values:
DaG 016 (H5) - DaG 299 (H4) - Dhofar 834 (H4) - Round Top (b) (H4)
Carancasically,
Bernd