Daohugou Beds - Geology

Geology

The geology of the Daohugou Beds is confusing because it is complex and does not conform; meaning that elements and layers of rock of different ages are mixed up together by folding and erosion and by volcanic activity. Liu et al. (2006) concluded that the rocks that bear the Daohugou Biota also include the Tiaojishan and Lanqi Formations. They demonstrated that the Jiulongshan Formation is older (Middle Jurassic), and that the Tuchengzi Formation is younger (Late Jurassic). However, many other researchers consider the Daohugou to be a part of the Jiulongshan Formation itself.

Fieldwork published in 2006 has also found that the beds are consistent over a large area; from western Liaoning into Ningcheng county of Inner Mongolia (Nei Mongol). The age of the Daohugou Beds has been debated, and a number of studies, using different methodologies, have reached conflicting conclusions. Various papers have placed the fossils here as being anywhere from the Middle Jurassic period (169 million years ago) to the Early Cretaceous period (122 ma).