Single-grain zircon U-Pb isotopic ages, geochemistry and its implication of the Pulang complex in Yunnan Province, China.

The Pulang complex in Yunnan Province is divided into three stages of intrusions based on their contacting relationship and petrological characteristics. The lithologies of the intrusions include quartz dioritic porphyry formed in the first stage, quartz monzonitic porphyry in the second stage, and granodioritic porphyry in the third stage. The crystallization ages of the intrusions were determined by using the, single-grain zircon U-Pb method. The single-grain zircon U-Pb isotopic ages are defined as 221.0 +/- 1.0Ma, 211.8 +/- 0.5Ma and 206.3 +/- 0.7Ma for the first, second and third stages of intrusions, respectively. These data combined with the results of petrochemical and Sr isotopic analyses support the formation of the Pulang complex in the Indo-Chinese epoch by multi-stages of gushing emplacement of the magmas derived from mixing source of mantle with crust.