Acfer 182 Gives new clues to chondrule formation

MARIA EUGENIA VARELA

Houston

Conferencia; Lunar and Planetary Science Conference; 2018

Acfer 182 is a member of the CH carbonaceous chondrite group characterized by smallchondrules (~90 ìm) and Ca-Al-rich inclusions (CAIs)[e.g., 1-2]. The parallel decrease in moderately volatileelement abundances with condensation temperatures,of metal and silicates, suggest a similar condensationhistory [3]. The chondritic Co/Ni ratios shown by metalgrains suggest that they experience a low degree ofmetamorphism, and was interpreted as a clue to itsnebular formation [e.g., 4-5]. The presence of metalwith compositional zoning signals fractional condensation from a cooling gas [6]. Therefore, it is widely accepted that the observed properties of the CH chondrites are the result of nebular condensation processes[1, 7-8]. Here, I report the study of Mg-rich cryptocrystalline (CC) and ferreous radiating pyroxene (RP)chondrules as a contribution to better constrain chondrule formation processes