Petrogenesis and mineralization potential of a granite porphyry intrusion beneath the Baishan Mo deposit, Eastern Tianshan, NW China

• The granite porphyry beneath the Baishan Mo deposit was intruded at about 228 Ma.
• The granite porphyry has an adakitic signature and originates from crust with a high degree of fractional crystallization.
• The granite porphyry hints on the existence of a porphyry Cu mineralization system at depth.

The Baishan molybdenum deposit is located in the eastern section of the Jueluotage tectonic belt, Eastern Tianshan. There is a granite porphyry intrusion beneath the Baishan Mo ore bodies discovered by recent exploration drilling, and the Cu–Mo minerals are widely distributed in the porphyry. The zircon LA-ICPMS U–Pb age of the granite porphyry intrusion is 228.1 ± 8.0 Ma, which is in coincidence with the age of Mo mineralization (227.7 ± 4.3 Ma). The granite porphyry intrusion is calc-alkaline and peraluminous. The magma was derived from a lower crustal source, it experienced distinct crystal fraction during its evolution, and the magma intruded in a Triassic compressional background, and was probably influenced by far-field effects of the Tethys system to the south. Based on the geological, geochemical and geochronological characteristics of the granite porphyry intrusion, we propose that there is probably a porphyry Cu deposit beneath the Baishan high-Re Mo deposit.