Lithosphere heterogeneity of the Dnieper-Donets basin and its geodynamical consequences. II part. Geodynamics interpretation
Journal Title: Геодинаміка - Year 2017, Vol 23, Issue 2
Abstract
Aim. Geodynamic interpretation of previously obtained 3D density and magnetic modeling results, and data on consolidated crust fault tectonics of the Dnieper part of Dnieper-Donets basin (DDB) in the light of its formation mechanism. Methodology. A detailed analysis of the structural relations of the sedimentary strata structure, crystalline crust block structure, and its fault kinematics in the Ukrainian shield (USH), Voronezh massif (VM) and their slopes during the late Proterozoic taking into account the seismotomography data for the deeper lithosphere horizons. Results. Features of the structure and the material composition of the consolidated crust DDB were formed as a "summary effect" of passive and active stages of rifting. Last and most likely, is the result of multi-phase linear elongated mantle diapirs (asthenolith). They correspond to the heterogeneity of modern subcrustal mantle and crust segmentation. Devonian DDB rift formed on the north-western suture zone separating the Precambrian basement domains of different composition and structure. The rift opening in the passive stage occurred along an ancient suture zone from the south-east to north-west with participation of dextral and rotational movements of the lithosphere blocks. The heterogeneity of the Precambrian crust and the right shears along inter-segment and latitudinal faults, in combination with rotational movements, caused the non-uniform stress fields and the formation of new inter-segment faults. Disappearance of the "granite" layer and partly decreasing thickness of "diorite" were the result of passive rift formation stage. The main factors of this active stage include the activation processes of the asthenosphere, crust reprocessing, bottom erosion, formation of velocity and density heterogeneities of the lithosphere, and its bottom relief. Crystalline crust of the DDB has a substantially greater basicity compared to surrounding structures. Its thickness increases from segment to segment from the North-West to the South-East, and is accompanied by a decreasing of the lithosphere thickness. The maximum contribution crust-mantle mixture to the basalt layer thickness is a sign of their activation. The asymmetric structure of the lower crust and mantle lithosphere indicate the presence of the inclined disruptions within the lithosphere, as part of the extension mechanism of the crust and mantle material penetration during the rifting. Formation of the sedimentary layer and its fault tectonics are caused by the structure of the crystalline crust. Originality. For the first time the heterogeneity of the lithosphere are considered as indicators of different stages of the rift formation (the initial passive and subsequent active). The role of shear deformations and rotational movements in the forming and development of the rift are shown. Practical significance. Established heterogeneity relations of the different layers of the lithosphere can be used to assess oil and gas prospects in the region.
Authors and Affiliations
V. I. Starostenko, I. K. Pashkevich, I. B. Makarenko, P. Ya. Kupriienko, A. S. Savchenko
Keywords
Related Articles
- EP ID EP455773
- DOI 10.23939/jgd2017.02.083
- Views 87
- Downloads 0
Synthetic and experimental frequency characteristics of near-surface layers under the seismic stations Trosnyk, Uzhgorod, and Mizhgirya
Purpose. In the paper, experimental spectral ratios between horizontal and vertical components of displacements from local earthquakes and noise recorded at the stations Uzhgorod, Trosnyk and Mizhgirya (frequency charact...
The lithofacies zonality and lithmological structure of Eifelian deposits of Dobrudja Foredeep
Purpose. The main purpose of this work is studying of lithology features of sedimentary complex of Eifelian age within Biloliskyi block of Dobrudja Foredeep. Methods. Methods include lithofacial, lithmological and minera...
Sedimentogenesis of early maykop (lower Oligocene) deposits in the Azov-Black Sea region
Purpose. Research of lithological features of the sedimentary complex of Early Oligocene within Azov-Black Sea Region and reconstruction of its sedimentary conditions. Method. The method includes lithologo-facial, minera...
Investigation of the relationship between the modern vertical displacement of the crust and seismic activity of Europe
Purpose. The main goal is to find the relationship between the generalized parameters of the vertical displacement of the earth's surface and the background seismic activity of the European continent by means of GNSS- te...
Anoxic sedimentogenesis of ediacaran and silurian strata of south-western slope of the East-European platform
Purpose. The objective of this study was to investigate the depositional environments of organic-rich Ediacaran and Silurian strata on the south-western slope of the East-European platform. In particular, the factors fac...