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Stonewall Formation
The Stonewall Formation is a Stratigraphy, stratigraphical unit of Late Ordovician to Early Silurian Geochronology, age in the Western Canadian Sedimentary Basin. It takes the name from Stonewall, Manitoba, and was first described in the Stonewall quarry by E.M. Kindle in 1914.Kindle, E.M., 1914. The Silurian and Devonian Section of Western Manitoba; Geological Survey of Canada, Summary Report 1912, pp. 247-261. Lithology The Stonewall Formation is composed of finely crystalline Dolomite (rock), dolomite, with a basal argillaceous and sandy dolomite (the Williams Member). Two thin sandstone beds occur in the middle and at the top of the formation. In the central Williston basin, the base is marked by an anhydrite bed. Distribution The Stonewall Formation occurs at surface in the Manitoba outcrop belt and in the sub-surface in the Williston Basin. It reaches a maximum thickness of . Relationship to other units The Stonewall Formation is overlain by the Interlake Group (confo ... [...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] |
