The morphology of the wide belt of lowlands is essentially due – as can be understood from the brief hints given – to the glacial phenomenon. During the Cenozoic, the Baltic reached as far east as Brześć with a large gulf, which then gradually filled up. In fact, paleogenic marine sediments are found throughout the easternmost section of this area, while neogenic sediments are found in the rest. During the Pleistocene glacial period the region was subjected to three glaciations: in its first the ice reached the foot of the Carpazî, also occupied largely by glaciers; during the second expansion the ice did not go beyond central Poland; and in the third, not beyond the low peribaltic belt. These ices left remarkable traces in the morphology of the country: large moraine deposits; wide furrows, sayings pradoliny, directed mostly from E. to O., which, as mentioned, were dug by ablation waters and are now partly dry or used by artificial canals; numerous groups of lakes; large swampy areas. For Poland 2005, please check ehealthfacts.org.
The peribaltic lowlands – it has already been mentioned – are limited to S. by the reliefs of Little Poland and Lublinese. The first, located west of the Vistula, between it and the border with Germany, are made up of Paleozoic and Mesozoic rocks, rich in useful minerals (especially coal), and are much older than the Carpathians. At one time their height must have been considerable: now the degrading work of atmospheric agents has reduced them to modest heights or has, in some places, even flattened them. Between the Vistula and its Pilica tributary, the Lysogóry rise to 612m. The importance of these reliefs is remarkable, both for the mineral riches they contain, and because, often descending on the surrounding lowlands, with steep cliffs, they constituted, in the past, almost a natural fortress: and there were, in fact, numerous castles, to defend the surrounding region. The reliefs of the Lublinese are formed of Cretaceous rocks, between the San and the Vistula in the West and the Bug in the E. The rock is also covered here by fertile black earth, which makes the region one of the best in Poland from an agricultural point of view.
A SE. of the hills that separate the Niemen basin from that of Prypeć extends the Polessia (in Polish Polesie, in Russian Poles ′ e), of which only the western half belongs to Poland while the eastern half is part of the territory of White Russia: a basin flat-bottomed, whose subsoil is made up of Cretaceous marls, covered by a thick blanket of glacial clays, on which in turn lie fluvio-glacial sands. The region is largely occupied by immense marshes (Rokitno or Pińsk Marshes, the largest in Europe) and large forests, and is rich in lakes and ponds. The scarce residents live in the drier areas, mostly in small wooden hut villages.
Towards S. the land rises and is covered by the bottom moraine of a large lobe of the Pleistocene glacier, which is crossed in wide valleys by the right tributaries of the Prypeć. The landscape becomes more rugged and more varied: you enter Volhynia (Wołyń), a low-lying hilly region (no more than 300 meters above sea level), where the Prypeć tributaries have carved out deep valleys with characteristic recessed meanders. We therefore have, always proceeding towards noon, Podolia (in Polish Podole, in Ukrainian Podille), a plateau (called Ripiano Podolico) formed by a granite base covered by almost horizontal layers of paleozoic schists, limestones and sandstones (Silurico, Devonico), on which Cretaceous and Neogenic sediments (sandy clays) lie, covered at their vaulted by a blanket of löss and č ernozem (in pol. czarnoziem) which makes the region very fertile. The plateau is N. more than 400 m high. and it goes down towards S. This is the direction of the watercourses, which have engraved it with deep and recessed valleys (especially those of the Dnestr and its tributaries). The northern edge of the Podolic Shelf descends steeply on the Bug plain and, tormented as it is by erosion, it has the appearance of a harsh and mountainous region, so much so that it is called Cołogóry (= bare mountains). Podolia, of which the western part belongs to Poland, continues towards the NW. in the Roztocze, a relief that rises to S. of the Lublin hills and that has a ridge parallel to that of the Eastern Carpazî. It is important because there is a watershed between the Baltic and Black Seas; here stands Lviv (Lwów),