Fission-track data and U–Pb dating of granites from Cameron Highland, Peninsular Malaysia: Evidence to comprehend exhumation episodes

摘要

Fission tracks are linear trails of intense radiation damage in the crystal structure of a mineral, produced by spontaneous fissioning of uranium-238 (238U) atoms. Detail information on the low-temperature thermal histories of rocks, below～120?°C for tracks in apatite and below～350?°C for zircon, can be provided by Fission-track (FT) analysis. The purpose of this article is to present apatite and zircon fission-track data, and U–Pb granite ages that provide information about the cooling histories of a rock which can be crucial in comprehending the exhumation episodes of the study area, in particular, and the region, in general. Granite samples were collected along the same vertical profile at different elevation, 178–944?m.a.s.l. These samples were used to determine Fission-Track and crystallization ages. HeFTy software was employed to interpret the cooling histories of the samples using forward and inverse models. The inverse model was an approach of reproducing the observed data, and it was carried out only for fission-track data from the apatite grains. And it was constructed after generating a number of forward models, where in each of these models the predicted apatite fission-track parameters were compared to the measured values. The apatite fission track (AFT) and zircon fission track (ZFT) data indicated expected age trends,i.e.the older ages at higher elevations and the younger ages at lower elevations. Similarly, the data shows that the apatite and zircon FT ages appear younger than the age of the rock crystallization. The U–Pb age in zircon consistently suggest the age of the granite is Late Triassic.