alluvial plains. An excerpt characterizing the Alluvial Plain

Arising as a result of the accumulative activity of large rivers. Particularly extensive alluvial plains arise when rivers wander in areas of tectonic subsidence. From the surface they are formed by river deposits (most often sands of various sizes), the thickness of which can reach up to several hundred meters (Indo-Gangetic plain, Congo depression, Hungarian lowland, and so on).

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An excerpt characterizing the Alluvial Plain

Summer has come without a hitch. And it was this summer (according to my mother's promise) that I was supposed to see the sea for the first time. I have been waiting for this moment since the winter, as the sea was my old “great” dream. But by a completely stupid accident, my dream almost turned into dust. There were only a couple of weeks left before the trip, and in my mind I was almost “sitting on the shore” ... But, as it turned out, it was still far from the shore. It was a nice warm summer day. Nothing special happened. I was lying in the garden under my favorite old apple tree, reading a book and dreaming about my favorite gingerbread… Yes, yes, gingerbread. From a small neighborhood shop.
I don't know if I've ever eaten anything tastier after? Even after so many years, I still remember the amazing taste and smell of this amazing delicacy that melts in your mouth! They were always fresh and unusually soft, with a dense sweet crust of icing that burst at the slightest touch. Stunningly smelling of honey and cinnamon, and something else that was almost impossible to catch ... It was for these gingerbreads that I was going to go without hesitation for a long time. It was warm, and I (according to our common custom) was dressed only in short shorts. The store was nearby, just a couple of houses away (there were three of them on our street!).

To the south of the boundaries of glaciation, the surface of the West Siberian Lowland is distinguished by an exceptionally monotonous relief, due to the predominance of river and lake accumulation processes in this territory for a long time. The region extends far south of the edge of the ancient ice sheet. However, ancient glaciation also played an important role in the formation of their relief.

When one speaks of the West Siberian Lowland as a gigantic alluvial plain, this part of it is usually meant.

The boundaries of the region are not clear enough and at present it is not possible to draw its border everywhere. It is especially difficult to draw a clear boundary with the foothill accumulative plain in the southeast, closer to the foot of the Altai, due to the similarity in the genesis of the relief of both areas: both are alluvial plains, although the reasons that caused accumulation are not the same.

In the middle part, adjacent to the lower reaches of the Irtysh and the middle reaches of the Ob, this geomorphological region is the most depressed and leveled. The lowest hypsometric marks are located outside the river valleys, in closed drainless depressions located along the left bank of the Irtysh. From here, in both directions, the terrain gradually becomes higher.

Small rivers often do not have morphologically expressed valleys. The slopes are extremely gentle, the channels resemble ditches. The weak undulation of the interfluve plateaus is revealed only due to the huge number of small lakes with peaty shores. As we approach the Central Siberian Plateau and the Urals, the vertical dissection of the relief gradually increases (Voskresensky, 1962).

An important role in the creation of morphosculpture belongs to suffosion-karst processes, which are associated with the formation of drainless depressions, closed basins, depressions, and steppe saucers characteristic of this zone (Meshcheryakov, 1972).

The areas of lacustrine and alluvial accumulation are also the Baraba and Kulunda lowlands lying to the south.

The Baraba lowland is an almost closed flat depression of the once large lake basin.

At the bottom of the depression, occupied by the Baraba lowland, two steps are observed. The first lower step is limited by contours of 110-120 m and occupies the southwestern part of the lowland. The second - higher - adjoins the Priobsky plateau in the east. The lower step of the lowland is characterized by a ridged relief. Also on the territory of the lowland there are many closed and semi-closed lake and swamp depressions.

There are many closed and semi-closed lacustrine bogs in the Baraba lowland. The sizes of the depressions are varied - from the depression of the lake. Chany, where only a mirror of water occupies over 2000 km 2, to swamp depressions with an area of ​​1-2 hectares. Many small basins - steppe saucers, occupied by swamps or lakes, are the result of leaching of easily soluble salts contained in the soil. Large depressions are of tectonic origin.

The Kulunda lowland resembles an elongated bowl-shaped depression open to the northwest. The central part is occupied by large lakes (Kulundinskoye, Azhbulat, Burlinskoye, Yarovoye, Maraldy) (Voskresensky, 1968).

In landscape terms, this territory is located within the southern taiga, deciduous forests and the transition zone from the forest zone to the forest-steppe (Alpatiev, Arkhangelsky, Podoplelov, 1976).

plains formed as a result of the accumulative activity of large rivers at the site of extensive subsidence of the earth's crust. Composed from the surface by river deposits, the thickness of which reaches several tens and even hundreds of meters (Hungarian lowland, plains along the valleys of the Ganges and Po rivers).

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