Title: Studies of Brazilian meteorites. XIII - Mineralogy, petrology, and chemistry of the Putinga, Rio Grande do Sul, chondrite Authors: Keil, K., Lange, D., Ulbrich, M. N. C., Gomes, C. B., Jarosewich, E., Roisenberg, A., ,
The Putinga, Rio Grande do Sul, chondrite (fall, August 16, 1937), consists of major olivine (Fa24.8), orthopyroxene (Fs21.3), and metallic nickel-iron (kamacite, taenite, and plessite); minor maskelynite and troilite; and accessory chromite.
Title: Studies of Brazilian meteorites. XIII - Mineralogy, petrology, and chemistry of the Putinga, Rio Grande do Sul, chondrite Authors: Keil, K.; Lange, D.; Ulbrich, M. N. C.; Gomes, C. B.; Jarosewich, E.; Roisenberg, A. ; Souza, M. J.
The Putinga, Rio Grande do Sul chondrite is described and classified as an L6. The mineral composition and some significant ratios of elements are reported, and the reasons for assignment to the L group and to petrologic type 6 are explained. The analysis suggests that maskelynite of oligoclase composition was formed by solid-state shock transformation of previously existing well-crystallized plagioclase at estimated shock pressures of about 250-350 kbar. This finding indicates that recrystallization (formation of well-crystallized oligoclase) preceded shock transformation formation of the maskelynite.