Earth Planets Space, Vol. 57 (No. 9), pp. e13-e16, 2005

Widespread magmatic activities on the angrite parent body at 4562 Ma ago

Naoji Sugiura¹, Akiko Miyazaki¹, and Keizo Yanai²

¹Department of Earth and Planetary Science, University of Tokyo, Japan
²Department of Civil and Environmental Engineering, Iwate University, Japan

(Received May 18, 2005; Revised July 26, 2005; Accepted July 27, 2005)

Abstract: Mn-Cr chronology of four quenched angrites showed that they formed nearly at the same time (4562 Ma) on the surface of the parent-body. Based on the chemical compositions, the cosmic ray exposure ages, and considerations on the thermal history of an achondrite parent-body, we suggest that the four angrites formed on top of a shallow magma ocean on the angrite parent body.
Key words: Age, angrites, Mn-Cr dating, SIMS.