STHZStatistic Study of Diagenesis—Mineralization Time Gap for Comagmatic Gold Deposits
TAN Jun, WEI Junhao, TAN Wenjuan, GUO Dazhao Faulty of Earth Resources, China University of Geosciences, Wuhan, Hubei, 430074
The diagenesis—mineralization time gap as one hotspot in gold deposit study is one important basis to confirm the genetic relationship between gold deposits and their cognate magmatites. Moreover, these gold deposits distribute broadly in China and the metallogeny and petrology for them are in the greatest details. In this paper, the authors collected published isotopic ages of some typical gold deposits and related intrusions to discuss the time gap distribution characteristic and range. According to data statistic and Kolmogorov rule test, the mineralizing events are coeval with or postdate comagmatic intrusions. The time gap obeys to normal distribution under 0.05 confidence level and cluster between 0 and 16.0 Ma averaging at about 7.0 Ma. Thus, if the time gap is ≤16.0 Ma, we should recognize the cognate relationship between the deposit and the intrusion. The authors also emphasize that for the exact diagenesis—mineralization time gap one should strengthen the study of geological setting of gold mineralization, pay attention to the combination between the time gap and trace elements and isotopic trace study, and explain the deposit genesis on the basis of both chronology and geochemistry.