SHRIMP U-Pb zircon geochronology of the ore-bearing rock in the Lengshuikeng porphyry type Ag-Pb-Zn deposit

Abstract：The Lengshuikeng porphyry Ag-Pb-Zn deposit is a unique typical porphyry Ag-Pb-Zn deposit in China, and no precise data concerning the porphyry mineralization age are available. Based on the SHRIMP zircon U-Pb chronologic study of 11 test points of zircon samples from Lengshuikeng porphyry Ag-Pb-Zn mineralized porphyry (granite porphyry), the authors obtained a weighted average 206Pb/238U age of (162.0 ± 2) Ma (MSWD = 1.4). Therefore, the Lengshuikeng granite porphyry was formed in (162.0 ± 2) Ma. Lengshuikeng porphyry geochronological ages of rock formation and ore formation show a high degree of consistency. There is no significant difference between rock-forming and initial ore-forming geochronological ages. In addition, the mineralization age deduced from rock-forming and ore-forming geochronological ages is about 27Ma in the Lengshuikeng ore deposit.