Etching of fission tracks in monazite: An experimental study. (19th March 2019)

• Record Type: Journal Article
• Authors: Jones, Sean; Gleadow, Andy; Kohn, Barry; Reddy, Steven M.
• 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: 179
• Page End: 188
• Publication Date: 2019-03-19
• Subjects: Earth sciences -- Periodicals; Geology -- Periodicals; 550
• DOI: 10.1111/ter.12382
• Languages: English
• ISSNs: 0954-4879

Abstract

Abstract: This study reports a range of etching and annealing experiments to establish the optimum conditions for the etching of fission tracks in monazite. The previously reported concentrated (12 M) HCl etchant at 90°C was found to cause grain loss from epoxy mounts and high degrees of grain corrosion, as did much longer etching times at lower temperatures. Using implanted 252 Cf semi‐tracks, a series of experiments were performed on internal prismatic faces of monazite‐(Ce) crystals from the Palaeozoic Harcourt Granodiorite (Victoria, Australia) using an alternative 6 M HCl etchant, also at 90°C. Step‐etch results show optimal etching at 60–90 min. Further, an isothermal annealing experiment illustrated that the degree of annealing that can be expected during etching at 90°C under laboratory time scales is negligible. The etching rate between grains is not uniform, with a correlation demonstrated between over‐etched grains and high U and Th concentrations.