A mega-sized gold deposit with 470.47 tons of reserves was found in Laizhou, east ?China?’s Shandong province, announced the Shandong Provincial No. 3 Institute of Geological and Mineral Survey on Monday. The gold deposit was 2000 meters under the north coastal water near Sanshan Island. It is the largest and ever first undersea gold mine found in China.

According to Ding Zhengjiang, the vice director of the said institute, the gold deposit is part of a crablike ore belt that lies deep at the sea bottom. Invested by Laizhou Ruihai Mining Ltd, the marine ground investigation took three years and involved over 120 kilometers of drilling, with 67 sea drilling platforms and nearly 1,000 geological workers at most.

“It’s very difficult to locate and set up the drilling platforms at sea,” Ding said. In 2012, the first platform took 24 hours to be constructed, and now it took only 8 hours with more advanced offshore construction technology. “Besides, drilling holes into underground rocks that are more than 1000 meters deep is a big challenge,” said the project manager Zhang Junjin. “Normally in China, gold mine prospection is conducted within 800 meters underground. The discovery of a gold deposit lying 2000 meters undersea provides new drilling technology for future gold mining,” Zhang added.