Geochemical heterogeneity of paleoestuarine basin of Vaneganskaya structure (Western Siberia)
Relevance of the work is determined by the complexity of creating sedimentary and facies models for the upper layers of the Pokursky suite. The aim of the research is to determine facies zones based on the factor analyses of the major oxides and geochemical indicators of the sediments of paleoestuar...
| Main Authors: | , , |
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| Format: | Article |
| Language: | Russian |
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Tomsk Polytechnic University
2019-05-01
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| Series: | Известия Томского политехнического университета: Инжиниринг георесурсов |
| Subjects: | |
| Online Access: | http://izvestiya.tpu.ru/archive/article/view/1525 |
| Summary: | Relevance of the work is determined by the complexity of creating sedimentary and facies models for the upper layers of the Pokursky suite. The aim of the research is to determine facies zones based on the factor analyses of the major oxides and geochemical indicators of the sediments of paleoestuarine basin and to observe their space-time evolution; to indicate the main factors influencing the sediment chemistry. The research methods: X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometer (ICP-MS) analyses, statistical data processing using the software package Statistica 6.0. The results. The factor analysis demonstrated that the variability in the contents of major oxides depends on the features of the mineral composition of sediment. 20-25 % of trace elements have a heterogeneous distribution which is caused by the accumulation of trace elements at the geochemical barriers. This fact indicates the variations of physical and chemical features of pH and Eh, which control the processes of water-sediment interaction. Based on the discrimination on geochemical and petrochemical factors the authors determined six facies-geochemical zones which correspond to beds (delta), oxbows, tidal zones, silted estuaries, shelf and areas of interaction of fresh and salt water. The lateral and vertical changes of the structure under study were found out. This shows the transition of continental facies into marine ones. It was ascertained that the petrogeochemical zonation is associated with the changes in substance ablation direction, water structure, hydrodynamic activity of depositional environment and physic-chemical conditions of sedimentation. The maximum influence of continental ablation is more clearly expressed in sediments of river and oxbow facies, and partially in the interaction areas of sea-land system. The variations of physic-chemical conditions (pH and Eh of the medium) are most distinctly expressed in reduction of acidity and redox potential from continental to shelf facies. |
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| ISSN: | 2500-1019 2413-1830 |