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a longitudinal external trough within geosynclinal systems, located near a platform and occurring on the same foundation. The miogeosyncline is usually characterized by a prevalence of sedimentary, predominantly carbonaceous, strata and minimal magmatism and metamorphism. Miogeosynclines are less mobile than the associated internal eugeosynclines. They become involved in folding later than the eugeosynclines, and the folding is sometimes intensive and complicated by overthrusts or even overthrust folding directed toward the platform (toward foredeeps). The term was proposed by H. Stille in 1964.