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Duluth Complex apatites: Age reference material for LA–ICP–MS‐based fission‐track dating
Author(s) -
Iwano Hideki,
Danhara Tohru,
Yuguchi Takashi,
Hirata Takafumi,
Ogasawara Masatsugu
Publication year - 2019
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/ter.12393
Subject(s) - fission track dating , geology , fission , homogeneous , track (disk drive) , mineralogy , absolute dating , apatite , paleontology , nuclear physics , quaternary , thermodynamics , physics , computer science , neutron , operating system
Anorthositic series apatites of the Duluth Complex, Minnesota, USA, have high spontaneous fission‐track densities of up to ~10 7 cm –2 and a homogeneous age of ~900 Ma, allowing high‐precision fission‐track dating based on LA–ICP–MS U analysis. Absolute fission‐track dating, track‐length measurement and chemical composition analysis were performed to evaluate a cooling history, which is essential for age reference materials. Preliminary inverse modelling for a sample with a shortened track‐length distribution yielded a monotonic cooling history from ~100°C at 925 Ma. The apatites incur an over‐etching problem when employing the commonly used etching protocol involving 5.5 M HNO 3 .