The Fossil Lake - evidence of the geological evolution in Non nuoc Cao Bang Geopark territory

Geological heritage also presents special geological procedures or context in the past or still continues until now. They can be geomorphological landscapes, paleontological and fossil sites, extinct or active craters, caves, canyons, natural lakes, waterfalls, natural outcrops of rock and ore, and even ceased mines.

Located in Thuc Phan Ward, the Fossil Lake consists of valuable geoheritage. The lake was formed in the Neogene era about 23 million years ago and has experienced many sea advance and receding periods, erosion, accumulations forming stacked thick layers with different colours like an installation work of nature.

According to geological research, these sediments originated from continental fine grains containing coal belonging to the Cao Bang Formation member 2, 30m long and 8-12m high. The thick 30Ð20 bedding was denuded over thousands, millions of years. Underneath sedimentary rock layers is a rashing layer containing thin bedded brown coal over 20m thick.

In addition, visitors can find here various fossils of carbonized plants and freshwater Pelecypoda mussels, Unionidae family, Bivalvia class, phylum Mollusca. Observed fossils are large and distributed in thick layers. Preliminary identified are varieties of Unio (mussels), Anodanta (mussels), Oxynaia (Lanceolaria fruhstorferi), their shells bear concentric ridges in white, soft, disjointed, the shell exterior retains ridges, the shell interior doesn’t retain ridges. Fossils are f 4-5 x 8-10cm. The fossil relics and rock represent an ancient humid fluvial-lacustrine-swampy environment.

The development of living organisms is closely related to the evolutionary history of the Earth's crust. Their existence and development depends on environmental conditions, such as temperature, depth, salinity, and light. Therefore, fossils are very valuable in defining the age of the rocks that contain them as well as the paleo-environmental conditions where they lived.

In each period of the stratigraphical development, there are specific fossils, which are explained by scientists with a lot of fascinating knowledge about the evolution of the Earth as well as the flora and fauna. The presence of fossils in the Geopark indicates that this special land in the past was a shallow sea with the presence of many plant and animal species. Fossils of plants and animals help us partially understand the evolution of the Earth and living hundreds of millions of years ago.

Being an outstanding site of geological interest consisting of traces of an ancient marine environment during the Neogene area together with the geomorphological landscape, the Fossil Lake offers visitors valuable experiences.

The Fossil Lake is a vivid evidence of the Earth’s evolution over millions of years. The installation of interpretation and direction panels here will help conserve and promote the heritage, while also providing opportunities for visitors, students, and researchers to explore and gain a deeper understanding of the geological, ecological, and cultural values of the Non Nuoc Cao Bang UNESCO Global Geopark.