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Further finds of the Derrick Peak meteorite, Transantarctic Mountains, and implications for terrestrial age
Author(s) -
Kirkbride Martin P.,
Bradshaw Margaret A.,
Harmsen Fraka J.
Publication year - 1991
Publication title -
meteoritics
Language(s) - English
Resource type - Journals
eISSN - 1945-5100
pISSN - 0026-1114
DOI - 10.1111/j.1945-5100.1991.tb01041.x
Subject(s) - meteorite , geology , glacial period , iron meteorite , chronology , cenozoic , isotopes of oxygen , paleontology , cosmogenic nuclide , geochemistry , astrobiology , cosmic ray , physics , structural basin , astrophysics
— Nine additional iron meteorite fragments weighing a total of 72 kg were recovered from the Derrick Peak area by a Canterbury Museum geological party in late 1988. One iron was located in the Onnum Valley, 6 km south of the previous finds. Geochemical analysis indicates that all irons belong to a single meteorite shower, greatly increasing the known extent of the fall zone. Kamp and Lowe (1982) have previously estimated the terrestrial age of the meteorite from glacial geological evidence. The location of the 1988 finds supports Kamp and Lowe's interpretation that the meteorites lie in situ , but recent revisions of the chronology of Cenozoic glacial history of the region reduce the interpreted terrestrial age. An age of between Oxygen Isotope stages 6 and 2 is probable (190–125 to 35–12 ka BP). This conflicts with a terrestrial age estimate of 1.0 ± 0.1 Ma BP from cosmogenic radionuclides.