Study of the closure temperature of (U-Th)/He in detrital zircon obtained from natural evolution samples

Abstract

Zircon (U-Th)/He thermochronometry was used as an effective indicator to study the thermal history of deep sedimentary basins with high temperatures. Zircon He ages and closure temperatures are very important parameters. In this paper, detrital zircon He closure temperature was studied by establishing the evolutionary pattern between zircon He ages and burial depth of borehole samples obtained from the Cenozoic strata in the Bohai Bay and Tarim basins, which have different thermal settings. The results show that the zircon He closure temperature of natural evolution samples is 200°C, which is higher than the temperature obtained from thermal simulation experiments (183°C). The temperature range of 140–200°C corresponds to the zircon helium partial retention zone. By properly understanding zircon He closure temperatures, zircon (U-Th)/He thermochronometry can provide a correct explanation of the He ages, and significant guidance in the study of the evolution of source rocks and the process of hydrocarbon accumulation in deep sedimentary basins.