Abstract:

Tongyugou copper deposit is located in the southeast segment of the Elashan polymetallic belt in Qimantage-Elashan ore-forming subzone. Based on the trace element geochemistry and the stable isotopes of Tonyugou copper deposit, this paper studied the source of ore-forming material and ore-forming fluids, identified the genesis of Tongyugou copper deposit. From the test results,the rare earth element distribution patterns are approximately consistent,the REE patterns are enriched in LREE and are depleted in HREE with high fractionation and negative Eu anomaly,demonstrating that the ore material comes from multi-source;sulfur isotope compositions δ³⁴S measurement are full-negative,belong to light sulfur type,revealing that the whole S was from the sedimentary sulfur; the demographics of Pb isotopic compositions showing that the lead was mainly from the ore deposition diagenetic stage,and partly from the Indosinian orogeny,which is closely related to Indo-Chinese orogenic movement. Hydrogen, oxygen and silicon isotope studies shown that the metallogenic fluids stemmed from magmatic water and mixed with metamorphism hydrothermal.The overall reflection show that the ore-forming material sources was related to the magmatic-hydrothermal activities. In general,Tongyugou copper deposit is a skarn type copper deposit.

Key words: ore-forming fluidlgeochemistrylskarn type deposit, Tongyugou copper depositlXinghai CountylQinghai Province