Mineralogy and Ar-Ar Age of the Tarahumara IIE Iron, with Reference to the Origin of Alkali-Rich Materials

MINERALOGY AND Ar-A t' AGE OF THE TARAHUMARA lIE IRON, WITH REFERENCE TO THE ORJGIN OF ALKALI-RICH MATERIALS. Hiroshi Takeda , Donald D. J3oga rd~, Mayumi Otsuki" and Teruaki Ishii, IResearch Inst. , Chiba Insl. ofTechno!ogy, 2-1 7-1 TsudanLlma, Narashino City, Chiba 275-00 16, 2Astromateria! s, Code-SR, NASA Johnson Space Center, Houston, TX , 77058, U.S.A, "Ocean Research Inst., Uni v. of Tokyo, 1151 Minamidai, Nakano-ku , Tokyo 164-001 4, Japan.