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Vanguard Formation
The Vanguard Formation is a Stratigraphy, stratigraphical unit of Callovian to Oxfordian (stage), Oxfordian Geochronology, age in the Western Canadian Sedimentary Basin. It takes the name from Vanguard, Saskatchewan, Vanguard, and was first defined by R.L. Milner and G.E. Thomas in 1954.Milner, R.L. and Thomas, G E., 1954. Jurassic System in Saskatchewan. In: Western Canada Sedimentary Basin. American Association of Petroleum Geologists, p. 250-267 Lithology The Vanguard Formation is composed of calcareous shale with a median quartzose sandstone. Distribution The Vanguard Formation Lateral reaches a maximum thickness of in the Williston Basin along the Saskatchewan/Montana border. Relationship to other units The Vanguard Formation is unconformity, unconformably overlain by the Mannville Group and unconformity, disconformably overlays the Shaunavon Formation. It is equivalent to the Ellis Group in Montana and North Dakota. Subdivisions In south-western Saskatchewan, Vangua ... [...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] |
