The Asuka-87 and Asuka-88 collections of Antarctic meteorites: Search, discoveries, initial processing, and preliminary identification and classification

• Main Authors: Keizo Yanai, Hideyasu Kojima, Hiroshi Naraoka
• Format: Report
• Language: English
• Published: National Institute of Polar Research 1993
• Subjects: Antarctic; Balchen; East Antarctica; Nansenisen; Queen Maud Land; Antarc*; Antarctica; National Institute of Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=4607; http://id.nii.ac.jp/1291/00004607/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=4607&item_no=1&attribute_id=18&file_no=1

Over 2400 pieces were collected by the Asuka wintering party of the 29th Japanese Antarctic Research Expedition (JARE-29,1987-89) on the bare icefields around the S∅r Rondane Mountains in Queen Maud Land, East Antarctica. The Asuka party searched almost all of the bare icefields around the mountains in the 1987-88 and 1988-89 field seasons. About 110 pieces (Asuka-87) of meteorites were collected on the bare ice around Mt. Balchen in the eastern part of the mountains in January and February 1988. In the first reconnaissance, about 240 pieces of meteorites (also Asuka-87) were recovered from the Nansenisen Icefield in February and March 1988. The Asuka-88 meteorites, over 2100 pieces, were found during the systematic search of this icefield during November 1988 and January 1989. The specimens were named officially the Asuka (A)-87001 to A-87352,and A-880001 to A-882124,in order of discovery. The Asuka-87 and Asuka-88 meteorite collections were filed as the National Institute of Polar Research (NIPR) meteorites with details of date of find, weight, dimensions and comments. According to the initial processing, the Asuka-87 meteorites comprise one iron, one stony-iron, 9 achondrites, 3 carbonaceous chondrites and over 300 ordinary chondrites, the total weight being 120kg. The largest specimen in the Asuka-87 collections is an LL-group chondrite of about 46kg. The Asuka-88 meteorites comprise 7 irons, 5 stony-irons, over 50 achondrites, 31 carbonaceous chondrites and over 2000 ordinary chondirtes. The total weight is about 400kg. Two specimens in the Asuka-88 collection were tentatively identified as a very coarse-grained and unbrecciated gabbroic meteorite and an olivine-fassaite-plagioclase achondrite with crystalline texture.