History of tectonics
The Kissing Cocks According to scientists, Hạ Long Bay has experienced at least 500 million years in various geological states of ontogeny, marine transgression and marine regression. During the Ordovician and Silurian periods (500-410 million years ago), Hạ Long Bay was deep sea. During the Carboniferous and Permian periods (340-250 million years ago), Hạ Long Bay was at shallow sea level.
Karts geomorphology value Due to a simultaneous combination of ideal factors such as thick, pale, grey, and strong limestone layers, which are formed by fine-grained materials; hot and moist climate and slow tectonic process as a whole; Hạ Long Bay has had a complete karts evolution for 20 million years. There are many types of karts topography in the bay, such as karts field.
Timeline of geologic evolution Some of the most remarkable geological events in Hạ Long Bay’s history in the last 1,000 years, include the advance of the sea, the raising of the bay area, strong erosion that has formed coral, and, pure blue and heavily salted water. This process of erosion by seawater has deeply engraved the stone, contributing to its fantastic beauty. Present-day Hạ Long Bay is the result of this long process of geological evolution that has been influenced by so many factors.
Due to all these factors, tourists visiting Hạ Long Bay are not only treated to one of the natural wonders of the world, but also to a precious geological museum that has been naturally preserved in the open air for the last 300 million years.
System of islets and caves
The bay consists of a dense cluster of over 3,000 limestone monolithic islands (although locals claim there are only 1,969 as this is the year of Ho Chi Minh’s death), each topped with thick jungle vegetation, rising spectacularly from the ocean.
Several of the islands are hollow, with enormous caves. Hang Đầu Gỗ (Wooden stakes cave) is the largest grotto in the Hạ Long area. French tourists visited in the late 19th century, and named the cave Garotte eds Versailles. Its three large chambers contain large numerous stalactites and stalagmites (as well as 19th century French graffiti). There are two bigger islands, Tuần Châu and Cat Ba, that have permanent inhabitants. Both of them have tourist facilities including hotels and beaches. There are a number of beautiful beaches on the smaller islands.
Some of the islands support floating villages of fishermen, who ply the shallow waters for 200 species of fish and 450 different kinds of mollusks. Many of the islands have acquired their names as a result of interpretation of their unusual shapes. Such names include Voi Islet (elephant), Ga Choi Islet (fighting cock), and Mai Nha Islet (roof). 989 of the islands have been given names. Birds and animals including bantams, antelopes, monkeys, and lizards also live on some of the islands.
Almost all these islands are as individual towers in a classic feeling landscape with heights from 50m to 100m, and height/width ratios of up to about six.
Another specific feature of Halong Bay is the abundance of lakes inside the limestone islands. For example, Dau Be island has six enclosed lakes. All these island lakes occupy drowned do lines within fencing karts