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Redonda Formation
The Redonda Formation is a geologic formation exposed in eastern New Mexico.Dobrovolny and Summerson 1947 It contains vertebrate fossils of the late Triassic Period.Griggs and Read 1959 Fossil theropod tracks have been reported from the formation.Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607. Description The formation consists of interbedded fine-grained red-brown sandstone and mudstone. It conformably overlies the Bull Canyon FormationLucas and Hunt 1989 and underlies the Entrada Formation. The formation is interpreted as having been deposited in a lake with an area of about . Fossils The formation has few fossil plants, with only '' Neocalamites'' reported, but it contains abundant invertebrate fossils (conchostracans and ostracods) and a diverse assemblage of vertebrate fossils. Vertebrate fauna Fish Stereospondyls Synapsids Archosauriforms History of investigation The unit was first named as the Redonda Member of the Chinle Formation by D ... [...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 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 Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
