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Engineering-Geological Interpretation of The Acoustic Structure of The Diamicton Strata of The Barents Sea Shelf
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Engineering and Mining Geophysics 2021, Apr 2021, Volume 2021, p.1 - 11
Abstract
Diamictons are mainly massive clay-silty clay with coarse-grained inclusions. There are two types of sections of diamicton formations in considered region. The first type is composed of overconsolidated stiff to hard soils. These formations have a ripple-mottled acoustic structure on shallow seismic time sections. Normally consolidated sediments represent the second type. In the upper part of sections there are very soft to soft varieties, which are gradually replaced with depth by firm, and then by stiff to very stiff ones. The similar deposits have an acoustically transparent structure. It is assumed, that these are Upper Neopleistocenian and Lower-Middle Neopleistocenian marine, glacial-marine sediments. Overconsolidated sections were formed by younger glacier pressure. The mottled acoustic structure of overconsolidated sediments is due to reorientation of particles and mineral aggregates under the pressure of the glacier, as well as an increase in the concentration of coarse-grained inclusions due to a decrease in the total volume of the soil mass as a result of compression. Normally consolidated sediments are developed in areas that were not covered by a glacier, or where it did not touch the bed with its bottom. Due to this, the described soils avoided overconsolidation and retained their original acoustically transparent structure.