ABSTRACT

This paper presents new apatite fission track (AFT) and apatite (U-Th)/He (AHe) data from the Duolong ore district. The corresponding AFT and AHe ages provide insights into the uplift and exhumation history of the Duolong ore district, revealing rapid exhumation with an erosional exhumation rate of 0.067 km/Ma between 65 and 35 Ma, and slow exhumation with an erosional exhumation rate of 0.023 km/Ma since 35 Ma. The new data in this study, along with previous low-temperature thermochronology data, show that samples with ages from 130 to 83 Ma are distributed close to Shuanghu in the central Qiangtang, samples with ages from 65 to 45 Ma are distributed evenly across the whole Qiangtang terrane, and several samples with ages from 20 to 7 Ma are distributed at the edge of the Qiangtang terrane. The Qiangtang terrane experienced heterogeneous surface uplift. The central Qiangtang was initially uplifted during the Early Cretaceous, and the weathered paleosoil dated between 120 and 110 Ma in the Duolong ore district is consistent with the exhumation during this period. Large-scale uplift and exhumation of the Qiangtang terrane between the Palaeocene and Eocene is consistent with the rapid exhumation of the Duolong ore district between 65 and 35 Ma; finally, the uplift and exhumation at the edge of the Qiangtang terrane since the Eocene caused the Duolong ore district to be uplifted to its present elevation.