Duluth Complex apatites: Age reference material for LA–ICP–MS‐based fission‐track dating. (20th May 2019)

• Record Type: Journal Article
• Authors: Iwano, Hideki; Danhara, Tohru; Yuguchi, Takashi; Hirata, Takafumi; Ogasawara, Masatsugu
• Other Names: Braun Jean guestEditor.; Spiegel Cornelia guestEditor.; Rahn Meinert guestEditor.; Tian Yuntao guestEditor.
• Is Part Of: Terra nova. Volume 31:Number 3(2019)
• Page Start: 247
• Page End: 256
• Publication Date: 2019-05-20
• Subjects: apatite -- Duluth Complex -- fission track -- LA–ICP–MS -- reference material; Earth sciences -- Periodicals; Geology -- Periodicals; 550
• DOI: 10.1111/ter.12393
• Languages: English
• ISSNs: 0954-4879

Abstract

Abstract: 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 HNO3 .