Ha Long bay listed UNESCO's World geological heritage

Dec. 12 (VNA) -- Ha Long Bay, a beautiful natural landscape in the northern province of Quang Ninh has been listed in the register of world geological heritage sites by the United Nations Educational, Scientific and Cultural Organization (UNESCO).

A news briefing was held in Quang Ninh on Dec. 11, where the UNESCO recognition was announced by the Ministry of Culture and Information and the Quang Ninh People's Committee and the Viet Nam UNESCO Committee.

Six years ago in Dec. 1994, Ha Long Bay was added to UNESCO's world natural heritage listing because of its natural and aesthetic values.

Now its geological values have also been recognized. According to Doctor of Science Tran Duc Thanh of the Oceanography Institute under the Viet Nam National Centre for Natural Science and Technology, and Prof. Tony Wal Tham of the UK Nottingham Trent University, Ha Long Bay's geological value covers regional geology, marine geology and particularly karst geomorphology.

Ha Long Bay is a mature karst landscape in a warm, wet, and tropical climate.

Within the bay, the main accessible caves are the older passages that survive from the time when the karst was evolving through its various stages of fengcong and fenglin. Three main types of caves can be observed in limestone islands: the remnants of old phreatic caves, old karstic foot caves, and marine notch caves.

The Bay has been invaded by the sea so that the geomorphology of its limestone islands are, at least in part, the consequences of marine erosion. The marine invasion distinguishes Ha Long Bay and makes it unique in the world. There are other areas of submerged karst towers which were invaded by the sea, but none as extensive as Ha Long Bay.

Besides, Ha Long Bay is of value in terms of the bio-diversity of its eco-system, such as the coral reefs and managrove areas on and around the islands of Ha Long Bay. In some caves, such as Sung Sot, Trinh Nu, Vung Ba Cua, Hoang Long, Dau Go and Bo Nau, there are many bats.

In many caves, archeologists have found remains and artefacts of Soi Nhu culture of the late Pleistocene period and the Ha Long culture of the mid-Holocene period. An old picture was also found on the roof of a cave on the west bank of Vung Ba Cua island. Dau Go cave is thought to be the place where the wooden stakes for the battle at the Bach Dang river in 1288 were hidden.

The Ha Long Bay area has valuable features of the Quaternary period. Quaternary sediment layers, the upper sea bed with a plain surface conserving ancient rivers, cave systems and deposits of sediments, and traces of marine activity forming distinctive notches are all important evidence of geological events and processes taking place at a time when human beings inhabited the earth.

In terms of marine geology, Ha Long Bay is recorded as a modern sedimentary basin, a bay created by a system of boundary islands. The bay has strong tidal currents, but weak winds. In the alkaline environment, the chemical erosion of the calcium carbonate proceeds rapidly, creating wide, strangely shaped marine notches. This appears to be an active process, creating new habitats for algae and plants living in the bay.

To ensure the sustainable development of this world heritage site, a museum on Ha Long's ecology will be built. Representatives from the Ha Noi UNESCO office met with the project's donors in Ha Noi on Dec. 11 to discuss the issue.--VNA