Uralian orogeny Uralian orogeny The Uralian orogeny refers to the long series of linear deformation and mountain building events that raised the Ural Mountains, starting in the Late Carboniferous and Permian periods of the Palaeozoic Era, c. 323–299 and 299–251 Mya respectively, and ending with the last series of continental collisions in Triassic to early Jurassic times. In terms of plate tectonics, the Uralian orogeny resulted from a southwestern movement of the Siberian plate, catching a smaller landmass, Kazakhstania, between it and the nearly completely assembled supercontinent, Pangaea. The mountains of Eastern Europe on the paleocontinent Laurussia, and those of Western Siberia
Sonoma orogeny arcs, composed of volcanic and volcaniclastic strata and paired geotectonically with Sonoma accretionary prisms to the east, are present in the Klamath-Sierran region of the Cordilleran orogen to the south of volcanic cover in the Pacific Northwest. Burchfiel and Davis presented a detailed model relating the Sonoma orogeny to convergent plate tectonic processes. They postulated an east-dipping subduction zone beneath a magmatic arc to the west of the continent. In this scheme, a back-arc basin floored by oceanic crust lay between the arc and the continent. The Sonoma orogeny involved closure of this basin and a process by which the