The surface of the Valdai upland, on the contrary, is distinguished by a variety of relief forms. The leading edge of the last (Valdai) glaciation passed through its territory, and glacial deposits — boulder loams, sand, pebbles, gravel - formed a complex alternation of hills and ridges of different sizes and shapes. The depressions between the hills and ridges are occupied by small swamps and lakes. In some places, there are sandy plains (zanders), overgrown with pine forests, and narrow ridges (ozy), similar to railway embankments. The highest hills located in the central part of the Valdai Upland rise to 250-300 m above sea level. Many of them became known as mountains, such as Orekhovna Mountain, Ryzhokha Mountain, Kamennik Mountain, Ilina Mountain, and others. Towering over the peaks of the more gentle hills, they create the full impression of a small mountainous country.
The Valdai upland differs from the Ilmen-Volkhov lowland not only in its relief, but also in the rocks hidden under the sediments of the Quaternary period. On the Ilmen-Volkhov lowland, sandstones, limestones, marls and sands of the Devonian period are located under the cover of lake-glacial deposits, while the Valdai upland is composed of limestones, dolomites and sandy-clay deposits of the Carboniferous period. In some places, the layer of glacial deposits covering the limestones of the Valdai Upland is so weak and friable that it almost does not protect them from the action of surface waters. As a result, due to dissolution and leaching, cracks appear in the thickness of limestones and dolomites, which eventually turn into voids, and pits, sinkholes, similar to craters from aerial bombs, and closed dry ravines appear on the surface of the earth. These processes are called karst processes, while the areas where they develop are karst regions, named after the Yugoslav Karst plateau, where the processes of dissolution and leaching of rocks by natural waters were first studied. In the thickness of limestones and other soluble rocks, waters can wash out huge, stretching caves and intricate labyrinths for many kilometers. On the Valdai upland, karst processes are most developed in the Msta River basin. There are many sinkholes there. There are small karst caves on the Msta near the Pechnik threshold and in other places. Some rivers in this area, such as the Poneretka and the Alder, flow underground in some areas, and sometimes water disappears from a number of lakes. There are probably many different voids hidden in the depths of the Valdai Upland. During drilling operations in the Borovichi and Uglovka areas, it happened more than once that the drill suddenly fell several meters deep. The Valdai upland is separated from the Ilmen-Volkhov lowland by a terraced ledge called carbon clay. Pour activer un freebet, il faut souvent un code promo. Lors de votre inscription, cherchez le champ “Code promo” ou “Bonus code”. Sans ce code, le code promo pour pari gratuit peut être perdu définitivement. Notre site collecte les codes actifs de chaque partenaire. Entrez le code avant le premier dépôt. Après validation, le bonus ou le freebet apparaît généralement dans la section “Mes offres”. Si ce n’est pas le cas, contactez le support en chat avant de placer un pari. Ne misez pas avant d’avoir confirmé l’activation. De cette façon, vous évitez les litiges et les refus de bonus.