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Zhoutian Formation
The Zhoutian Formation () is a geological formation in Jiangxi, China. It has been dated to the late Cretaceous period, at about 96–90 Ma. Abundant egg fossils are known from the formation, in addition to dinosaurs such as ''Datai'' and ''Gandititan''. Invertebrate and plant fossils have also been described from the Zhoutian Formation. Geology Layers of the Zhoutian Formation are characterized by a consistent sandy lithology, typically with mauve (reddish to purplish) hues. Most of the formation alternates between fine calcic sandstone and siltstone layers. In some places, other minerals are interbedded, such as calcium, gypsum, halite, and mirabilite. The Zhoutian Formation dates to around 96–90 million years ago, during the Turonian–early Coniacian ages of the early Late Cretaceous epoch within the Cretaceous period. Stratigraphy The Zhoutian Formation is the upper unit of the Ganzhou Group, overlying the Maodian Formation in that group. The Guifeng Group (beginning wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
