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Date submitted2008-10-25
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Date accepted2008-12-02
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Date published2009-12-11
Composition of retrospective geological systems and significance of structural-tectonic factor in paleogeographic reconstructions
- Authors:
- V. P. Matveev
Models of geological objects are represented as the static, dynamic and retrospective systems. Paleogeographic reconstruction relates to a typical retrospective system. Its objective composition becomes possible on the basis of the lower rank systems: static and dynamic. Comparison between paleogeographic reconstructions in time shows the significance of tectonical factor in the forming of paleolandscape of the territory. Information on paleobiocoenosis is necessary for estimation of paleoclimate. The Author’s field investigation materials of the geological mapping on a scale of 1:200 000 at the Novaya Zemlya archipelago are taken as the basis of paleogeographic and paleofacies reconstructions.
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Date submitted2008-10-11
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Date accepted2008-12-21
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Date published2009-12-11
Cyclicity of the devonian and carboniferous deposits of Novaya Zemlya
- Authors:
- R. A. Schekoldin
Two structural-formational zones are recognized in the Devonian and Carboniferous deposits of Novaya Zemlya: the Barents zone and the Kara zone. The first one is characterized by thick, predominantly carbonate deposits, containing a rich complex of benthic fossils, and corresponds to the shelf paleoenvironments. The second one is characterized by thin hemipelagic argillaceous, lime and siliceous deposits, containing scarce pelagic fossils. This zone is suggested to represent bathyal paleoenvironments (slope and basin floor). The main control on sedimentation in both zones provided relative sea-level rises and falls, which repeated with mean periodicity equal to an age (third-order cycles). Sea-level highstands correspord to periods of low sedimentation rates and stagnation in deep-water zone. Sea-level lowstands were favourable to intensification of sediment gravity flows and better aeration of bottom waters.