China's state-of-the-art research ship used to explore for oceanic mineral resources, Dayang Yihao, or Ocean One, berthed at Qingdao port Friday morning after completing its 21st expedition.

The mission discovered five new hot liquid sulfides areas -- two in the Atlantic Ocean, two in the Pacific Ocean and one in the Indian Ocean -- chief scientist for maritime exploration Tao Chunhui said.

Scientists call hot liquid sulfides "black chimneys," according to Tao, and they are an important oceanic mineral resources that provide clues for the study of the origins of life.

A new remotely operated underwater vehicle (ROV) that can collect samples from as deep as 3,500 meters underwater accomplished its first mission exploring the "black chimneys" by taking a sample.

The hydrothermal sulfide samples contained a variety of metals, Tao added.

The expedition also mapped out the ocean floor for possible future deep-sea mining operations and collected sea life samples.

Setting off from China's southern coastal city of Guangzhou last July, Dayang Yihao travelled 53,300 nautical miles (about 98,712 kilometers) over 315 days and visited the Pacific, Atlantic and Indian oceans.

The expedition was divided into eight work trips and about 216 scientists and staff took part in the mission.

China began oceanic scientific research in the 1970s and drew up its oceanic mine resource plan in 1984. It has since established hi-tech work platforms for deep-sea mineral exploitation, transport and smelting.

Dayang Yihao, China's major oceanic scientific research vessel, was launched in 1995. (Xinhua)