RECHARGE SOURCE IDENTIFICATION AND EVOLUTION OF INFLOWING WATER IN A SEABED GOLD MINE

This paper aims to capture the evolution rules of fracture-inflowing water at the shallow depth of Xinli gold deposit exploited under seawater. From a hydrogeochemical point of view, it uses the principal component analysis and maximum likelihood method to identify the water-recharging sources of the inflowing water and estimate their mixing ratios. Using numerical modeling, the paper verifies indirectly the inflowing water evolutionary character and calculates it with the proposed method. The research shows that the method can effectively identify the combined patterns and variations of end-members of mine inflowing water, and calculate the most possible mixing ratios. The end-member model of the fracture-inflowing water of the Xinli gold mine has been changed from the type Ⅰ bedrock saline water+seabottom groundwater to the type Ⅰ bedrock saline water+seabottom groundwater+seawater. The sea bottom groundwater and seawater are prone to percolating into the mine pit from the shoulders of its both sides. The seawater percentage of the mine inflowing water goes through an increasing first and decreasing history.