BEIJING, Feb. 26 -- The State Oceanic Administration (SOA) on Tuesday hailed achievements by Chinese scientists onboard an oceanic research vessel surveying polymetallic deposits in the southwest Indian Ocean as "beyond anticipation."

The "Dayang-1" vessel arrived at the ocean's polymetallic sulfide exploration contract area on Jan. 26 and left on Feb. 19.

Scientists onboard the vessel discovered two seafloor hydrothermal areas and four hydrothermal anomaly areas, and deepened understanding about the overall area.

They also gained insight on the origins of of carbonate hydrothermal areas, and made successful attempts to explore for sulfide, said the SOA.

Hydrothermal sulfide is a kind of sea-bed deposit containing copper, zinc and precious metals such as gold and silver. Those metals formed sulfides after chemical reactions and came to rest in the seabed in "chimney vents."

Dayang-1 gathered three carbonate pieces and a "chimney vent," the first time Chinese scientists have collected such a structure from the southwest Indian Ocean.

The team also secured many other samples, and two people designated by the International Seabed Authority were trained during the expedition.