Along with 99 other sites from 53 countries worldwide, Ha Long Bay – Cat Ba Archipelago has been recognised as a World Geological Heritage Site by the International Union of Geological Sciences (IUGS).
This information was shared on August 25 by Associate Professor Dr. Tran Tan Van, former Director of the Institute of Geosciences and Mineral Resources under the Ministry of Natural Resources and Environment.
Dr. Tran has played a significant role in preparing and leading submissions for two World Heritage dossiers related to outstanding geological values and directly worked on the dossier that secured Ha Long Bay – Cat Ba Archipelago’s recognition as a World Geological Heritage Site.
The site was recognised for two globally significant values: its geological history and karst geomorphology, characterised by distinctive landforms commonly marked by underground drainage systems in karst caves.
The IUGS is expected to announce the list of 100 IUGS Geological Heritage Sites during the 37th International Geological Congress (IGC), scheduled to take place from August 25-31, 2024, in Busan, the Republic of Korea.
Ha Long Bay represents the later stages of the tropical karst submergence process, while the Cat Ba Archipelago adds significant geological value through its terrestrial and intertidal phases.
Ha Long Bay was first recognised as a UNESCO World Natural Heritage Site in 1994 for its outstanding aesthetic value. In 2000, it received a second UNESCO designation for its global geological and geomorphological significance. Most recently, on September 16, 2023, Ha Long Bay – Cat Ba Archipelago was acknowledged as Vietnam's first inter-provincial UNESCO World Natural Heritage Site at the 45th session of the World Heritage Committee.
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The Cat Ba Archipelago, located in Cat Hai District (Hai Phong), consists of 367 large and small islands, featuring smooth white sand beaches with crystal-clear water where one can see the bottom. (Photo: VNA) |
The recent IUGS recognition further underscores the exceptional value of this heritage site.
According to Dr. Tran Tan Van, Ha Long Bay – Cat Ba Archipelago exemplifies a mature karst landscape formed under tropical, humid, monsoon conditions, with its development shaped by recent marine transgression. The area remains partially submerged in seawater today.
The limestone formations in Ha Long Bay – Cat Ba Archipelago, along with other regions in northern Vietnam such as Ha Giang, Cao Bang, Lang Son, Bac Kan, Thai Nguyen, and Quang Binh, were primarily formed in warm, shallow marine environments around 300 million years ago.
Ha Long Bay features a diverse range of geological elements, including islands interspersed with deep marine basins, and striking contrasts between coastal mangrove forests and towering limestone islands with vertical cliffs. This is considered one of the oldest observable geomorphological features in Vietnam.
On the mainland and islands, erosion is evident in sedimentary hills, limestone mountains, and caves at various elevations. Submarine features of note include ancient river channels, remnant karst blocks, and submerged karst fields.
The distinctive landscape of Ha Long Bay – Cat Ba Archipelago, along with its renowned geological and geomorphological features, is the outcome of over 500 million years of regional geological evolution. This long history is also why UNESCO has recognised Ha Long Bay as a World Natural Heritage Site three times.
