Sierra Gorda 013: Unusual CBa-Like Metal-Rich Chondrite

M. A. Ivanova, Sh. Yang, M. Humayun, C. A. Lorenz, I. A. Franchi

51st Lunar and Planetary Science Conference (2020), Abstract #1116


“The metal-rich (>20 vol% Fe,Ni-metal) carbonaceous chondrites include CH chondrites, CB chondrites [e.g. 1-3] and the Isheyevo CH/CBb chondrite [4]. The CB chondrites are rare and divided into two subgroups based on their petrologic characteristics: CBa (e.g., Bencubbin, Weatherford, Gujba) and CBb (e.g., Hammadah al Hamra (HH) 237 and Queen Alexandra Range (QUE) 94411/94627) (e. g. [5]. A recently described chondrite, Quebrada Chimborazo (QC) 001 is similar to CBa but unusual in containing shock melt and high pressure mineral phases [6]. Fountain Hills (FH) is closely related with CBa meteorites but distinct from the other CB chondrites [7]. FH contains 23 vol.% metal, significantly lower than other members of this class, it contains porphyritic chondrules, which are extremely rare in other CBa chondrites. Here we report new data on mineral chemistry, oxygen isotopic composition and bulk trace element chemistry of metal and silicate phases of SG 013 and discuss their origin. Preliminary results on SG 013 were represented by [8].”