Geological - Geomorphological values

The geological history of Ha Long bay area spans for about 3 billion years and is scientifically recorded for 500 million years. Evidence of geological evolution and tectonic movement,including fault zones,geodesy, geysers, basins, and formations that marked dramatic changes in paleo-geographical conditions in the area. Halong Bay has experienced many periods of marine transgression-regression, thus it contains precious values to the Anthropoceneand marine geology.
 

 Vịnh Hạ Long - cảnh quan karst trưởng thành trong điều kiện nhiệt đới nóng ẩm bị biển xâm lấn

The geodiversity of Ha Long Bay is diverse in terms of sediment composition; geomophology, structure and geological evolution; The richness of the ancient and modern sediments with the particular historic geologic periods has created a variety of topography, geomorphology and natural landscapes.

     Ha Long Bay’s geological -geomorphological outstanding universal values are recognised because this is an extensive and best known example of marine-invaded tower karst being experienced many periods of marine transgression-regression. The combination of elements such as thick limestone (as thick as 1000 m), hot, humid climate and slow tectonic uplift with full phases of a modern marine cycle have created an excellent karst pattern of large-scale limestone known as a wonderful geological wonder.

Ha Long Bay’s karst geomophology includes almost all basic karst form, such as karst field, peak cluster-depression, landforms with sharp peaksinter-connected with each other to surround isotropic. The period of sea invadingin late Pleistocene and late Holocene have been directly involved in the karst process in Ha Long, creating particular kart forms, such as sea notch and foot caves. Sea also invaded closed, rounded karst poljesto become saltwater lake or “tùng”,“áng”. Caves in Ha Long bay divided into 3 types: remnants of phreatic caves; old karst foot caves, and marine notch caves.

 Ha Long bay is also a place of geological aspects that are valuable for scientific research, such as fossils, crystalline mineral masses in rock,folds, clusters on cliffs,slides and breccata of the tectonic fault,karst topography and modern marine terrain,and sea notches, which are all evidences of ancient sea level.

     Ha Long bay’s geological - geomorphological outstanding universal values should be fullystudied preserved for future generations.

Phòng Nghiệp vụ Nghiên cứu