Within the Gobi desert, there are cliffs called the Flaming Cliff or Bayanzag. This name comes from the color of the sand that looks to ignite when the sun sets. Indeed, the Flaming Cliff are composed of clay that gives them this red color. This clay is an important part of the Jurassic and the Cretaceous Mongolian history.
The fossils of the desert
The Flaming Cliff are known worldwide for the many discoveries of fossils of dinosaurs. In the 1920s, Roy Chapman Andrews was the first Explorer to discover fossils of dinosaurs of the Gobi desert. He is best known for having discovered the first fossilized dinosaur egg.
The Flaming Cliff revealed for example fossil of a Velociraptors fighting a Protoceratops. Often, the dinosaurs died buried by sand as the fossil of a mother trying to protect her eggs in the sand. Through the sand that became subsequently clay dinosaurs have been very well preserved. This sudden death under tons of sand, and burial of the bodies has allowed a rapid fossilization of many dinosaurs.
Formation of fossils
The clay comes from the erosion of the volcanic rocks and marine sediments. These sediments are the basis of the fossilization of the dinosaurs. Indeed, the formation of a fossil is very difficult. When the living thing dies (tree, plant, animal, etc…), it must quickly be covered not sediments to avoid that other organisms consume. If it is not gloutonne, the body covered by sediments goes see her soft matter apart from oxygen environment. The son of the time, it will remain only the parties hard, bone, teeth, etc… Then other conditions need to be made. If the fossil is too close to the surface, it will rise and the parts will be scattered, making it impossible to fossilization. If the corpse is in depth, through pressure and temperature, it won’t move. Sediment will then break in the parties and via a chemical alteration, will make the hard body. He’s going to turn into stone. Finally, if the fossil remains at the bottom of the Earth, via the temperature and the pressure he will be destroyed. However, via plate tectonics plates, the fossil can be traced back and this is where it is preserved and that it becomes accessible to researchers of fossils.
The Flaming Cliff, an ancient oasis
Thanks to the high concentration of fossils that have been discovered in this place, we can easily rebuild the environmental conditions during the Jurassic and Cretaceous. The Gobi desert, was already a desert but with variations of lower temperatures. Indeed, there is an oasis with dense vegetation in the vicinity of the Flaming Cliff. Thus, this oasis included a high biodiversity within the desert. That is why we find so many fossils. There is always such an oasis in the vicinity of the cliffs, it is the only forest in the Gobi.
For all definitions: go to this page.
For the time scale is here!
“The Altaids of Central Asia: A tectonic evolutionary and innovative review.” WHILEM C., WINDLEY B., SCOTT G., 2012
“Evolution of the Early Permian volcanic-plutonic complex in the western part of the Permian Gobi – Altay Rift (Khar Argalant MTS., SW Mongolia); David burianek1 *, Pavel HANŽL, Petr BUDIL, Axel GERDES, 2012
Science and the future http://www.sciencesetavenir.fr/archeo-paleo/archeologie/comment-se-forment-les-fossiles_104192