China's deep sea manned submersible Jiaolong discovered lots of new active "chimney vents" in southwest of Indian Ocean on Monday.

"Chimney vents, " also known as hydrothermal sulfide, is one 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."

"While Jiaolong navigating for about three kilometers, we saw lots of active chimney vents with hydrothermal fluid blowing out, which are higher and sharper than the ones we had found in other areas." Tao said.

"Some chimney vents are as high as 20 meters, so it is very hard for the pilot to operate the sub to reach there." Tao said. "And it's difficult to measure temperature of hydrothermal fluid blowing out of chimney vents and to take samples as well."

The temperature of one active chimney vent, which Jiaolong measured with a special probe in its iron-hand, was 379 degree Celsius, said Tang Jialing, who piloted Jiaolong and managed to collect some hydrothermal fluid, hot deep-sea water and sulfide for scientists.

Having investigated this area before the dive, Chinese scientists had collected some sulfide but had discovered no active chimney vent aboard a scientific vessel, according to Tao.

"It's better to go and have a look with manned sub if you are really interested in some deep-sea areas, and you will have astonishing discoveries." Tao said.

After Liu Xiaohui, a 26-year-old pilot trainee of Jiaolong, returned to the support ship on Monday, all six pilot trainees of Jiaolong have finished their first dive as copilots.

"When they finish three dives in oceans as copilots, they will be asked to pilot Jiaolong under instructions of experienced pilots." said Yu Hongjun, chief commander of the expedition.

Reaching its deepest depth of 7,062 meters in the Pacific's Mariana Trench in June 2012, Jiaolong is on a 120-day expedition in southwest of Indian Ocean (Xinhua).