Petrologic and Chemical Characterization of a Suite of Antarctic Diogenites

• Main Authors: Peng, Z. X., Mittlefehldt, D. W., Mertzman, K. R., Mertzman, S. A.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2013
• Subjects: Geophysics; Antarctic; Antarc*
• Online Access: http://hdl.handle.net/2060/20140000330

The origin of diogenites, ultramafic cumulates related to eucrites, is an unresolved problem [1]. Most diogenites are orthopyroxenites, a few are harzburgites [2], and some are transitional to cumulate eucrites [1, 3]. Cumulate eucrites are gabbros formed by crystal fractionation from basaltic eucrites [4]. The consensus view is that basaltic eucrites are residual melts from global-magma-ocean crystallization on their parent asteroid [4] which is plausibly Vesta [5]. However, the petrologic and compositional characteristics of diogenites seem to preclude a magma ocean origin [1, 4]. We are doing a petrologic and chemical study of new or unusual diogenites with the ultimate goals of constraining their genesis, and the geologic evolution of Vesta.