The Putorana Plateau: Tectonics, Morphotectonics, and Exodynamics

The Putorana plateau is a unique area in the North of the North Siberian tableland. A flat surface of a plateau covered by the basalt lava flows has an area of over 1500 thousand of square kilometers and an elevation in the Central part more than 1500 m (max 1701 m). The plateau is dissected almost to the entire height by narrow canyons with a depth more than 800–1000 m with characterized steep stepped slopes and riverbeds with waterfalls. Bottoms of canyons occupied by the rivers and narrow deep lakes length more than hundred km and depth to some hundred meters. The structure of relief of the plateau has inversion character. Basalt lava effusions from fractures in the axial zone of the Tunguska basin, interlayered with the pyroclastic covers of tuff, formed in the Permian and Triassic periods a “layer cake” of horizontal volcanogenic layers with different resistance to denudation. Inversion of the tectonic regime beginning in the late Mesozoic period and common uplift of the earth crust over a mantle plume formed a high plateau which surface is conformal the basalt cover structure. Regional dome deformation defined radial spatial pattern of deep valleys with a centrifugal river network, which inherited the opened tectonic fractures. The morphologic sculpture of the plateau was formed under the domination of denudation processes began at the end of Mesozoic and prolonged in all Cenozoic period. Deep river erosion has a selective character, extreme values of depth and inherits the weakened tectonic zones on the background of the prevailing uplift and a sustainable substrate. The alternation of resistant and pliable volcanogenic strata with subhorizontal layering sets a clear step structure of the slopes and river beds of the valleys and affected to localization of denudation and accumulation processes. Pleistocene glaciation played a significant role in the formation of topography features of the plateau and has different spatial and temporal character in different parts of the plateau. Foothill accumulation of the end moraines of outlet glaciers along the western periphery of the plateau formed a barrier to modern runoff and contributed to the development of extensive lake basins—“Great Norilsk Lakes.” Modern geomorphologic processes on the plateau clearly differ by levels: (a) surface of the plateau—the dominance of weathering and aeolian processes; (b) upper parts of the slopes are characterized by steep scarps, denudation niches and deep erosion valleys; (c) lower parts of slopes is covered with rockfalls and debris-flow plumes. Cryogenic processes are widespread at all territory of the plateau. Relict glaciers found in some high parts of the plateau.