Quang Ninh Province

Quang Ninh Province ist the easternmost province, with a border to the People's Republic of China in the east. The southern border of the province is a meandering coastline, with numerous estuaries and tidal flats. About 80% of the province is hillcountry.

The most interesting feature of this province, at least from the subterranean point of view, is Ha Long Bay, listed in the UNESCO World Heritage List. It is a part of the Gulf of Tonkin, and an impressive example of tower karst. The karst development produced a huge number of limestone towers, separated by valleys with generally flat floor. They are interpreted as former cave systems which collapsed and the debris was eroded too. The remaining towers are also heavily karstified draining into the valleys.

In this area, because of the rise of the sea level after the last ice age, most of the valleys are flooded today. The valleys formed about 80m above sea level during the ice age. The melting ice caused a rise of the sea level by 100m and today the valley floor forms a 20m deep sea floor, still showing the signs of ancient streams. The karst towers became islands and the result are some 1,600 islands and islets with caves.

The islands do not have surface water because of the karstification, and groundwater is contaminated by the sea water and thus salty or brackish. The lack of sweetwater is the reason why most of the islands are uninhabited and unaffected by a human presence.

Hospital Cave |

Dong Sung Sot

Quang Ninh Province

See also