New A Tectonic Chart Of The Arctic

On the tectonic chart, that great part of the Arctic and sub-Arctic territory where the crust is of continental type is subdivided into fold systems, recent geosynclines and parageosynclines. The fold systems in their turn are subdivided into two groups, basically as follows: PreCambrian systems, which have passed through the stage of postgeosynclinal development have been converted into platforms; Paleozoic and Mesozoic systems, still in the stage of post-geosynclinal development. The recent geosynclines are subdivided into two groups: mature geosynclines --- Cenozoic fold systems that have entered (or are entering) into the stage of post-geosynclinal development; young geosynclines, still in the initial stages of geosynclinal development, and related to geostructures of oceanic type. The parageosynclines are subdivided on the chart into three groups: peripheral parageosynclines --- zones of geosynclines formed in marginal downwarps, in foredeeps, and in part in submontane downwarps; internal parageosynclines, associated with the central massifs found in the interior of folded regions; finally, certain oceanic depressions with protracted and intense subsidence.