The geological history of the Ukraine is entirely different from that of the rest of Europe. The pre-Cambrian core of gneiss-granite of the Ukraine, unlike other parts of Eastern Europe, was not flooded by the sea either in the Cambrian period or the lower Silurian, while in the upper Silurian the sea covered only a slight part of Western Podolia and Northern Bessarabia. The Devonian sea crossed the boundaries of the Ukraine only in the farthest east (Donetz Plateau) and west (Western Podolia). The [6]carbon deposits and Permian formations, so widely distributed in Eastern Europe, are found in the Ukraine only on the Donetz; triassic rock hardly at all. The Jurassic Sea confined its action almost wholly to the plicated borderlands of the Ukraine, altho it actually flooded great stretches of Eastern Europe. Only the extension of the chalk seas thru Eastern Europe affected Ukrainian territory, especially the northern and western borderlands. The old tertiary sea, on the other hand, confined itself for the most part to the Ukraine, with the result that a goodly section of the northeastern boundary of the old tertiary deposits coincides exactly with the anthropogeographical boundaries of the Ukraine. The inland seas of the lower green-sand formation of Eastern Europe, too, are confined almost entirely to Ukrainian territory. The geologic history of the Ukraine in the diluvian period was also decidedly different from that of the other districts of Eastern Europe. The Northern European inland ice covered the northwestern borderlands of the Ukraine only in the main ice period, for the boundary set for the glaciation of the north, on the basis of the investigations of Russian scholars, applies in great measure only to the limits of the distribution of northern glacial boulders, which were carried to their present site not by ice but by flowing water. The two indentations of the glaciation-boundary in the Don and Dnieper district merely mark the sphere of action of two glacial river systems. The absence of a one-time inland-ice-cap differentiates the Ukrainian district very markedly from the other parts of Eastern Europe. As we perceive, even from this short description, the Ukraine has had an entirely different geologic history from the rest of Eastern Europe. More plainly still, the independence of the Ukraine as a natural unit is revealed in its contour-line and surface-relief. [7]The Ukraine is the only portion of the Eastern European plain which has access to the mountainous region, for it rests upon the Carpathians, the Yaila Mountains and the Caucasus. Important individual districts of the Ukraine lie in these mountains and lessen the Eastern European uniformity of the country. The formation of the Yaila and the Caucasus began at the end of the Jurassic period—its completion and the building up of the Carpathians occur in the late tertiary period.