Giant Mountains, being the highest range of the Sudetes, play a much larger and more important role, than it would appear from this simple statement. They are also the highest mountains in the Czech Republic, and in Prussia there were no higher ones.
Extensive, the clearly uplifted massif of the Karkonosze Mountains is the main part of the Western Sudetes. Hence, they were previously associated in descriptions with the Jizera Mountains, having a similar geological structure and being their natural extension towards the west, up to the Lusatian Gate. The eastern border of the Karkonosze Mountains is marked by the Lubawska Gate. Highest towards midnight, the border ridge descends steeply to the Jelenia Góra Valley. In the western part, at the foot of the main ridge, there is a lower range of hills, cut into individual side ridges by the valleys of numerous rivers and streams. It is the Karkonoskie Foothills between the Kamienna valleys in the west and the Łomnica valleys in the east. It connects to the main ridge through a clear alignment, called the Karkonoski Padoł Śródgórski.
Currently, it is assumed that the Karkonosze Mountains extend from the Szklarska Pass (8.86. mi. in the west to the valley of the Bóbr river on the east (in the Gate. Lubawska) a strand of approx 36 km. The main ridge of the Karkonosze Mountains is divided into several parts by mountain passes. From the west, between the Szklarska Pass and the Śnieżka Pass (1394 m) the Silesian Ridge extends, additionally cut into two parts by the Karkonoska Pass (1198 m).
In the western part, Wielki Szyszak culminates in it (1509 m), and in the eastern part of Smogornia (1489 m). Further east, between the pass under Śnieżka and the Owl Pass (1164 m), the highest part rises with Śnieżka (1603 m) and the Black Ridge with the Black Kopa (1407 m). The next section between the Sowia Przełęcz and the Okraj Pass (1046 m) is the Kowarski Ridge with the Rock Table (1281 m), and the last one – to the Lubawa Gate – Lasocki Grzbiet with Łysocina (1118 m), in the Czech Republic it is called Pomezni hrbet in the northern part, and in the southern part Rychory.
The Czech Krkonoše Mountains are more fragmented: they consist of several ridges and extensive foothills. The most important thing here is the two-component one, Vnitfni hrbet, cut in half by the Elbe valley (also known as the Bohemian Ridge). It connects with the Silesian Ridge on Labske Louce in the west, and Bile Louce (Równi pod Śnieżka) on the east. Its western part departs to the east of Ko-tel and is called Krkonośa, and the eastern one extends to the west of Studnićnia hora and Lućni hora and is called Kozi hrbety. The southern part of the Czech Karkonosze Mountains is formed by the foothills with many, generally meridional lying ridges, which is called Krknośske rozochy (Karkonoskie bifurcations), referring to the shape of this area. This is not surprising, if taken into account, that the Polish part covers only approx 185 km2, and Czech as much as 465 km2.
Like most mountains, the Karkonosze Mountains are also very different from the north and south. From the north, from the Jelenia Góra Valley, they have the shape of -a distinct shaft and -sharp slopes, while from the south they gradually pile up with successive strips, they grow on higher and higher mountain ridges. From this side, they do not make such a monumental impression; even Snow White, very clearly towering over the surrounding area, seems less impressive.
This is mainly due to the geological structure and differences in relief. The main part of the Karkonosze Mountains from the west to the Śnieżka Pass, ending from the east on Równia pod Śnieżka, they build Variscan eranitoids. The Śnieżka itself is mostly made of hard hornfels, and the rest of the ridge to the east of it is built mostly by Proterozoic gneisses, mica schists and metamorphised granites (granitogenic), at the foot of which there are also green squares, conglomerates and greywackes.
Various rocks and minerals appear in these formations, for example basalt in the Little Snowy Cauldron, arafibolity, fullness, magnetyt, uranium, corundum, amethysts, grenades, beryl and many others. The Karkonosze area was also included in the gold-bearing area, but no deposits of minerals and polymetallic (except for iron and uranium ores in Kowary) did not matter much. Numerous quarries were also in operation, mainly granite.
In terms of geological structure, the Giant Mountains are among the old mountains, but their present form is the result of the Variscan orogenic movements dating back some three hundred million years, followed by a period of erosion and denudation, damaging rocks and exposing deep-sea granites. Their main mass was raised again in the period of the Tertiary Alpine Orogeny, but its individual fragments rose unevenly, divided by faults and cracks, partially filled with effusive rocks. This movement covered only the Karkonosze Mountains, while the Jelenia Góra Valley has not been raised. As a result of orogenic movements and the subsequent erosion and denudation periods, the Karkonosze Mountains acquired a characteristic appearance of a wide ridge with the features of a flat peak, from which the heartwood domes of the individual peaks grow.
After the alpine orogenic movements ceased, there was a period of intense erosion, especially intense during ice ages and after the retreat of the ice sheet. It was then that the most attractive elements of the sculpture were created, lending some fragments of the Karkonosze Mountains, as the only Sudeten range, features of high mountains of the alpine type. The most visible traces of this period are the glacial cauldrons falling down the rocky walls, at the foot of which there are load and inflow cones, and below the bottom moraines, frontal and marginal, ponds and glacial lakes, high and medium bogs. Airing and high mountain, the almost polar climate led to the formation of such distinctive wreaths’ debris, turf mounds (thufurs), structural land, sandbar, debris gutters, and above all, countless beautifully shaped rocks, which the Karkonosze Mountains are simply dotted with and which make them attractive for tourists. On their surfaces, you can see well-formed air vents, and in the beds of rivers and streams – marmity, that is, post-glacial pots (erosive cauldrons). These are funnel-shaped depressions in the rocks forming the riverbed with diameters from several centimeters to several meters and depths sometimes reaching several meters. They arose mainly in the post-glacial period, when the intensively flowing waters made the stones spin, and even great boulders in hollows of rock. These stones, turning around, they gouged wells.