Rb-Sr and Sm-Nd Study of the D'Orbigny AngriteD'Orbigny, is a relatively a new angrite find. Angrites are achondrites that show unique mineralogy and typically ancient crystallization ages. D Orbigny has been described extensively by. We have initiated a study of D Orbigny. A Pb-Pb model age of 4559 Ga has been reported. The presence of Pu-244 fission Xe in D Orbigny has also been reported. We present Sm-Nd and Rb-Sr results and a Mn-53-Cr-53 study is in progress. We had expected to find a relatively well-behaved Sm-Nd system, and distinct evidence for the Sm-146-Nd-142 system. Emphasis in this study was placed on the precise measurement of initial Sr-87/Sr-86, since primitive initial Sr-87/Sr-86 may be characteristic of the angrite parent body. Sr isotope measurements were obtained in the recently completed laboratories at JPL, using the ThermoFinnigan Triton mass spectrometer. Due to lower amounts of Nd and Sm, Sm-Nd data were obtained on the Lunatic I spectrometer at Caltech, due to established high ionization techniques, on this instrument using light rare earth oxide ions.
Document ID
20030111621
Acquisition Source
Headquarters
Document Type
Conference Paper
Authors
Tonui, E. K. (California Inst. of Tech. Pasadena, CA, United States)
Ngo, H.H. (California Inst. of Tech. Pasadena, CA, United States)
Papanastassiou, D. A. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)