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Kap Stewart Group
The Kap Stewart Group is a geological geological unit#Group, group in eastern Greenland of Late Triassic (Rhaetian) to Early Jurassic (Sinemurian) age. It consists of a 155-600 m thick sequence of interbedded mudstones and fluvio-deltiac sandstones deposited in a "large wave and storm-dominated lake". Description Originally known as the Kap Stewart Formation, it was later raised to Group status. It comprises three formations, the organic-rich lacustrine mudstones with interbedded sheet sandstones of the Rhætelv Formation (developed in the basin centre) the alluvial plain sandstone and conglomerate of the Innakajik Formation overlain by delta plain sandstones to mudstones of the Primulaelv Formation (both restricted to the basin margin). References {{Reflist Geologic groups of Europe Geologic groups of North America Geologic formations of Greenland Jurassic System of North America Paleontology in Greenland ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Unit
A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features (facies) that characterize it. Units must be ''mappable'' and ''distinct'' from one another, but the contact need not be particularly distinct. For instance, a unit may be defined by terms such as "when the sandstone component exceeds 75%". Lithostratigraphic units Sequences of sedimentary and volcanic rocks are subdivided the basis of their shared or associated lithology. Formally identified lithostratigraphic units are structured in a hierarchy of lithostratigraphic rank, higher rank units generally comprising two or more units of lower rank. Going from smaller to larger in rank, the main lithostratigraphic ranks are Bed, Member, Formation, Group and Supergroup. Formal names of lithostratigraphic units are assigned by geological surveys. Units of formation or hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |