Switzerland is par excellence a state of mountains, hills, plateaus, without plains. About 60% of the territory is included in the Alpine region, which occupies the central-eastern and southern parts. A NO. the ranges of the Jura rise. Between these and the Alps lies a relatively depressed region, made up of hills separated by wide valleys and plateaus, which occupies about 30% of the entire state. It degrades towards NO. up to a wide flat furrow, on which the Jura mountain descends steeply, while the Prealps slope down towards the central region without a well-defined border. Three natural regions are therefore distinguished in Switzerland, and to them correspond different geological structure, diversity of landscapes and forms of life.
Switzerland, which includes most of the Central Alps, and also a strip of the Mont Blanc group (but you did not include the maximum peak), embraces one of the highest and most complex sections of the system. A fundamental morphological character is constituted by the presence of the wide longitudinal furrow in which the high courses of the Rhone and the Rhine flow; crosses it entirely with direction SO.-NE. and the asymmetry of the slopes is characteristic: at N. the mountain ranges descend almost vertically on it from their maximum elevations, while the other slope is formed, at least at both ends, by a series of more or less branched mountain ranges, which branch off from the highest peaks culminating further to China The Rhine and the Rhone from the central and highest part descend, one towards the NE. and the other towards SW., to then change direction and cut both the Alpine chain with a transversal valley. This longitudinal groove, which certainly existed even before the great Quaternary glaciers overcharged it and gave it its present shape, is very high in correspondence with the high valleys of the Rhine and the Rhone and at the Urseren Tal, which constitutes the central part and is crossed from the Reuss, but its bottom sinks to less than 500 m. in the Rhone valley, less than 600 in that of the Rhine: especially in the Valais, peaks above 3 and 4 thousand meters, and the side valleys, almost always suspended, send the waters through wild gorges or picturesque waterfalls.
To China of the longitudinal furrow just described, Switzerland includes first of all the northern slope of the Pennine Alps or the Valais Alps, with Mount Rosa (4638 m.), Which present Switzerland with a wider slope than that facing Italy; but the mountain ridges that branch out there, separated by wild valleys, remain very high (over 3-4000 m.) and descend towards the Rhone valley like imposing bastions, while it is also on this side that the largest glaciers. The Lepontine Alps rise from the Simplon pass to the Spluga pass, of which Switzerland also includes most of the southern side. The groups of M. Leone, the Ticino Alps with the China Gottardo and the Adula are distinguished. The mountains that rise around the Gotthard Pass and Urseren Tal (Dammastock, China Gottardo group, Finsteraar: v. below) form the heart of Alpine Switzerland. There is the largest hydrographic node of the Alps, from which the waters flow from all sides (Reno and Aar, Rhone, Toce and Ticino). The great road marked by the Ticino-S. Gotthard-Reuss valley, connects the Po Valley with the Rhine, the Mediterranean with the North Sea: at its central point it crosses the mentioned longitudinal furrow, the widest breach that opens in the heart of the Alps. The China Gottardo and the surrounding mountains therefore constitute an orographic, hydrographic, commercial and strategic node of the utmost importance.
To the E. of the Spluga Pass, the Rhaetian Alps rise, divided into two parts by the upper longitudinal valley of the Inn or Engadina: to the NW. the Albula and Silvretta groups descend on it, which instead send long and branched ridges towards the Rhine separated by a whole series of valleys; to SE. it is the imposing Bernina massif (4052 m.) of which only the north side belongs to Switzerland. This whole eastern section of the Swiss Alps is rich in passes (Bernina, Maloggia, Giulio, Albula, Fluela).
At N. of the Rhône-Rhine longitudinal furrow, in the heart of Switzerland, between the Rhône and Reuss valleys, the Bernese Alps rise, with the harsh limestone groups of Diablerets, Wildhorn, Wildstrübel, therefore the imposing crystalline group the Finsteraarhorn, which boasts some of the most famous peaks in Switzerland (Jungfrau 4166 m., Finsteraarhorn 4273 m., Aletschhorn 4182 m., etc.), and the largest ice area in all the Alps; between the Aare and Reuss valleys the Dammastock massif, from which the Rhone glacier descends.
At E. della Reuss, the Glarus Alps still exceed 3500 m. in the Tödi group (m. 3623).
The actual Alpine ranges are preceded on the northern side by the Swiss Prealps. The distinction between the Alps and the Pre-Alps is anything but clear-cut; however the Prealps are less elevated and form a landscape distinct from the Alpine one. However, it is not homogeneous in all its extension, but with a variety of aspects and structure: the compact longitudinal chains of the Friburghese Prealps are succeeded by the most varied and fragmentary forms of the Central Prealps, isolated in massifs by numerous valleys and rich in lakes, while the Prealps of St. Gallen or of Thur to the NE. they are dismembered by wide transversal valleys that penetrate to the heart of the mountain.
The geological structure of the Swiss Alps varies: to the South. of the Rhône-Rhine longitudinal furrow, the crystalline soils of the axial zone of the Alpine chain prevail; to N. the ancient crystalline soils constitute the massifs of Finsteraarhorn, with Dammastock, and of Tödi; then the external limestone area extends, consisting mainly of Cretaceous limestone, alternating with the tertiary sandstones of the Flysch and also the molasses and puddinga at the outermost edge of the Alpine world. But the limestone Alps are not very extensive in Switzerland, compared to the eastern section of the chain, because a grandiose demolition of external agents has largely removed the cover of limestone strata of the Tertiary.
Tectonically, the Swiss Alps correspond to one of the most complicated parts of the system, in which the carriageways (see alps) overlap each other, affecting up to the external area of the molasses and tertiary puddynes. In the heart of the region is one of the ancient Hercinian massifs that formed the primitive backbone of the Alps: the Aare-San Gottardo massif (Finsteraarhorn, Dammastock, China Gottardo, part of the Tödi).
Between the Alps and the Jura, between the lakes of Geneva and Constance, it stretches over a length of about 300 km. a region of low mountains, hills, plateaus, all transformed into meadows and fields, rich in industries and traffic. It is designated by various names: the most suitable seems to be that of “Mittelland” that is “central country”, and so it really is, not only because it forms the central part of Switzerland between the Alps and the Jura, but also because it is its center. economic and demographic: here we will designate it “Central Plateau”.
Geologically and geographically it represents the foreland of the Alps. It essentially consists of molasse and puddinga from the Tertiary sector alternating with Quaternary alluvial deposits, moraine deposits and glacial and fluvio-glacial terraces.
During the Middle Tertiary, in the sea and fresh waters spreading in this part of Switzerland, the streams that descended from the Alpine chain, which had already undergone the first grandiose uplift, deposited their debris which gave rise to the current molasses formation.. In the lower Tertiary, when the last alpine uplift took place and the folds of the Jura formed, this area, which almost formed a penepiano, was raised and, at the edge of the Alps, also strongly folded. The great Quaternary glaciations then came to transform its appearance. The ancient diluvial glaciation covered the whole country, even reaching the Jura. In the great interglacial, the running waters almost completely removed the deposits left by the glaciers: in the meantime, following a lowering of the base level of the Rhine in the Alsatian plain, the watercourses of the north-eastern part of the Plateau, sinking to connect to it, dug into the layers of the molasse large and deep valleys descending towards the Aare and the Rhine. The great furrow that stretches at the foot of the Jura already existed. The recent diluvial glaciation, even if less extensive than the ancient one, was of great importance in determining the forms of the landscape.
While the Jura descends like a barrier on the furrow at its foot, the border of the plateau towards the pre-alpine ranges is uncertain, nor can it be identified with that of the molasses formation because mountains (Rigi, etc..) which have an alpine character.
In the Central Plateau, four main parts can be distinguished: first of all the sub-Jurassic furrow, which stretches at the foot of the Jura, towards SW-NE, and welcomes the lakes of Neuchatel and Biel, once much more extensive and then the course of the Aare: there are the only flat areas, somewhat extended, in Switzerland, at a height that can be calculated between 400 and 500 meters; to the west the Friborg plateau, in which the Sarine has dug its series of deep meanders.
In the center you can see the Napf mountain, furrowed by a range of deep valleys with steep sides (Graben) that radiate towards the wide peripheral valleys of Entlebuch and Emmental, and the Aare valley rich in glacial deposits; NE. finally, the Central Plateau is formed by a whole succession of valleys with SE.-NO direction, filled with large glacial deposits, often occupied by lakes, separated by parallel ridges.
The northwestern tip of Switzerland, from Lake Geneva to the Rhine and Aare, is part of the limestone mountainous area of the Jura. It essentially belongs to the folded Jura, with its characteristic regular series of parallel folds with a SW-NE direction. (crêtes), which close valleys (vals) which often widen into basins without surface drainage because the waters filter through the calcareous soil; with the combes, high basins that erosion has dug by affecting the hinge of the anticlines; with the picturesque gorges of the cluses, which by cutting the ridges transversely allow the water courses to exit the longitudinal valleys. The mountainous folds, which enclose large basins in the Upper Jura of Neuchâtel, appear more tightly in the Upper Bernese Jura. The maximum height of the Swiss Jura is reached by Mount Chasseral (1650 m.). At China del Reno, between Basle and the confluence of the Aare, the “Tabular Jura” stretches: it represents the sedimentary area that settled at the foot of the Hercinian massif of the Black Forest. in which the waterways dug wide valleys, when, as already mentioned the base level of the Rhine in the great interglacial, their erosion work was reactivated.