Thermo-Tectonic History of Archean Basement Rocks in the Aktash Tagh, Southeastern Tarim Craton: Constraints From Zircon U-Pb, Zircon and Apatite Fission-Track Dating

Abstract

Stable craton lithosphere can undergo complex tectonic events at its margins due to peripheral tectonic activity. In this study, we conducted a comprehensive analysis of zircon U-Pb dating, apatite and zircon fission-track thermochronology on the Aktash Tagh complex in the southeastern margin of the Tarim Craton. The obtained apatite fission-track ages range from ∼219 Ma to ∼104 Ma, while the zircon fission-track ages span from ∼1,400 Ma to ∼100 Ma. The zircon U-Pb ages from double dating of 261 grains range from ∼3.6 Ga to ∼1.9 Ga. The complexity of our zircon fission-track ages is attributed to the presence of both high-retentive zircons and low-retentive zircons. High-retentive zircons indicate that the samples have not been exposed to temperatures above the zircon fission-track reset temperature (∼350°C) since about 1.0 Ga. We can identify in the study area reheating events at ∼2.0–1.9 Ga and post 1.4 Ga, as well as cooling events at ∼1.9–1.8 Ga, ∼1.4 Ga, and ∼1.0 Ga. We conducted inverse thermal history modeling using QTQt software that revealed two significant thermo-tectonic events: (a) rapid rock cooling during the Middle to Late Jurassic, and (b) renewed rapid cooling from the Oligocene to the present day. The former cooling event may have been related to the collision between the Lhasa Block and the southern margin of Asia, while the latter is generally linked to the far-field effects of the India-Eurasia collision.