Low temperature thermal history reconstruction using apatite fission-track length distribution and apatite U-Th/He age

TL;DR

This paper introduces a new method combining apatite fission-track length data with U-Th/He ages to reconstruct low-temperature thermal histories more efficiently, avoiding the need for complex irradiation procedures.

Contribution

It presents a novel approach to decouple apatite fission-track age from length data and integrate it with U-Th/He ages for thermal history modeling.

Findings

Successful implementation of the combined method using 'Low-T Thermo' program.

Demonstrated that the method provides reliable thermal histories.

Reduced laboratory complexity by avoiding irradiation and LA-ICP-MS.

Abstract

Low temperature thermochronology plays a key role in the study of tectonic evolution of the upper crust. The general application of thermal history modelling of apatite fission-track analysis requires both the parameters of the apparent age together with the confined track-length distribution of the spontaneous tracks. However, obtaining length data is relatively easy and does not require either irradiation or LA-ICP-MS commonly used for determining the uranium content of the grains for age dating. This leads to a shorter laboratory process. For this purpose, based on apatite U-Th/He method, this paper attempts to decouple apatite fission-track age from apatite fission-track length, and then combine the lengths with the respective apatite U-Th/He age to model the thermal history. Therefore, experiments were designed and conducted using a new program "Low-T Thermo". Results of this modelling are presented from the following experiments: apatite fission-track age combined with apatite U-Th/He age; apatite fission-track confined track-length distribution plus apatite U-Th/He age. The modelling precision using this method is related to the relative errors of the apatite U-Th/He ages and the helium diffusion model. This combination of apatite fission-track length and apatite U-Th/He ages has not been implemented before but is presented here as an alternative way of determining thermal histories without the addition of apatite fission-track ages.