Fission-Track Analysis: Field Collection, Sample Preparation and Data Acquisition

Fission-track (FT) analysis for geological applications involves a range of practical considerations, which are reviewed here. These include field sampling, the separation of the most commonly used minerals (apatite, zircon and titanite), the preparation of these minerals for analysis (including for double or triple-dating of the same grains) and measurement of the essential parameters required. Two main analytical strategies are described, the External Detector Method (EDM) and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS). Although the initial steps ranging from sample selection to mineral separation are common to both approaches, the next practical steps vary with the specific dating strategy adopted. The workflow outlined here for sample preparation and aspects of data acquisition follows a widely used standard sequence of steps, but some of the specific details described are those developed over many years by the Melbourne Thermochronology Group. While these protocols may be readily applicable or adaptable, it is recognised that many laboratories may have developed their own particular recipes for different aspects of these methods.