Zircon fission track thermochronology constraints on mineralization epochs in Altai Mountains, northern Xinjiang, China

The mineralization ages reported in the past in the Altai Mountains, northern Xinjiang, China, not only are different, but also fall into the Hercynian epoch. This study has achieved 17 zircon fission track analysis results from different ore deposits. The zircon fission track ages range from 134 +/- 9 Ma to 339 49 Ma. We consider that the zircon fission track age could reveal the mineralization age based on an annealing zone temperature of 140-300 degrees C and a retention temperature of similar to 250 degrees C for zircon fission tracks, and a metallogenetic temperature of 150-260 degrees C in various ore districts. The mineralization age agrees with the regional tectonics. A total of four mineralization epochs have been identified, i.e., 339312 Ma, 255-234 Ma, 218-174 Ma and 158-126 Ma, and these indicate occurrence of the mineralizations in the Indosinian and Yanshan epochs as well as the Hercynian epoch. (C) 2009 Elsevier Ltd. All rights reserved.