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a geosyncline, either between the continental craton and the oceanic crust or near the margin of a continental mass, capable of alpine folding and frequently associated with primary magmatism. An orthogeosyncline has a significant longitudinal trend and is the parent of folded mountain structure. It usually consists of longitudinal belts, both eugeosynclinal, with intensive magmatism, and miogeosynclinal, with little or no magmatism. The term “orthogeosyncline” was proposed in 1940 by the German geologist H. Stille.