LA-ICP-MS zircon U-Pb dating of the Tongcun porphyry in Kaihua County, western Zhejiang Province, and its geological significance

This paper reports the LA-ICP-MS zircon U-Pb ages of granite porphyry in Tongcun, Kaihua County, Zhejiang Province. The age ranging from 167.6 to 155.6 Ma suggests an intrusion process of magma in Middle and Late Jurassic. Jurassic was a tectonic active period during the Yanshanian movement. Regional tectonic stress field of that time characterized by NW-trending extrusion and NE-trending tension formed a series of NE extrusion faults and NW-trending tension faults. The intersection of faults, known as the weak stress area, provided essential invasive channels for large-scale magmatic intrusion in Mesozoic. Therefore, the Tongcun ore deposit not only represents a typical case of Jurassic molybdenum mineralization in west Zhejiang Province but also indicates a very optimistic prospect of mineralization, because magmatic and tectonic activities were very active in Jurassic.