Discovery of the Yamato Meteorites in 1969

The first discovery of Yamato Meteorites by an inland survey team of the Japanese Antarctic Research Expedition (JARE) in 1969 was reported by Yoshida et al. (1971). However, there are important events, issues, and data related to this discovery that have so far not been published. Prior to the author's departure for Antarctica, M. Gorai suggested the author to consider collecting meteorites during the trip. On 21 December 1969, when geodetic measurements for the 250 km span of a triangulation chain were approaching its completion, members of the inland survey team collected three stones on the surface of the ice sheet in the southeastern marginal area of the Yamato Mountains. The author realized that these rocks were possibly meteorites, recalled the suggestion by M. Gorai, and requested all members of the team to collect other possible meteorites while conducting the geodetic survey. After returning to Japan, the nine stones collected in Antarctica were all identified as meteorites by M. Gorai. The concept of a mechanism by which meteorites became concentrated in the area in which they were found, involving the flow, structure, and ablation of the ice sheet, was developed in the field in 1969 during the collection program, and was mentioned briefly in Yoshida et al. (1971); a schematic figure was shown in a Japanese newspaper in the same year. With all these as background, further collections of meteorites in the Yamato Mountains were conducted in the 1973 and 1974-1975 seasons, and a project involving the collection of meteorites was formally incorporated as an important component of the work undertaken by the geology group within JARE from the 1975-1976 season onwards. (C) 2009 Elsevier B.V. and NIPR. All rights reserved.