SIMS study of glasses in the Cachari eucrite: One more piece of evidence for a common source for all glasses in meteorites?

MARIA EUGENIA VARELA; KURAT GERO,; ZINNER ERNST,; BRANDSTAETTER FRANZ,

Viena

Congreso; European Geoscience Union (EGU05); 2005

Cachari is a monomictic basaltic eucrite that contains abundant darkglass veins. The petrogenesis of eucrites is still an unsettled problem (e.g., Jurewicz et al., 1993; Righter and Drake, 1997; Ruzicka et al., 1997; Stolper 1997; Warren, 1997; Newsom and Drake, 1982; Mittlefehldt and Lindstrom, 2002) with the main question unsolved: where does the basaltic liquid come from? Nevertheless, independent of the beliefs and the lack of consensus on the origin of eucrites, almost all researchers agreethat the glasses, which are common in them, are the result of an impact process on the eucrite parent body. This belief is based on the fact that the major-element chemical compositions of glasses are similar to those of their respective host bulk rock. Here we will compare glasses in eucrites with those from other achondritic meteorites and propose a different and new hypothesis on the origin of glasses and the role of silicateliquids in meteorites.