The Geology of Switzerland

The general picture of the physiographic map of Switzerland reflects the tectonic structure rather directly. Local relief in the Jura Mountains is a direct consequence of folding of the detached Mesozoic strata. The Swiss Plateau mimics the Molasse Basin with flat lying sediments while thrusting and tilting of these strata in the Subalpine Molasse amalgamated these units with the Alps. The Alps exhibit nappe stacks of very different origin. Most of them evolved from pre-Triassic crystalline basement rocks and their sedimentary cover. In many cases the cover was detached from its basement and now forms a nappe stack of its own. The Helvetic nappe system derived from the European continental margin contains nappes of cover rocks displaced over 30–50 km; crystalline basement rocks form large-scale domes. The Penninic nappe system is derived from basins that formed in Mesozoic times between the European and Adriatic continents. They contain far travelled nappes of cover rocks, as well as nappes of basement rocks that were transported over considerable distances, too. In addition, nappes of oceanic rocks outcrop as thin slivers at the top. Post-nappe folding within the Penninic nappe stack is reminiscent of their complex formation history. The Austroalpine nappe system was derived from the Adriatic margin and now forms a horizontal layer as the highest unit in eastern and central Switzerland. This nappe system contains crystalline basement as well as Mesozoic cover rocks and was emplaced early in the Alpine history in a ENE direction. The Southalpine nappe system was derived from the Adriatic margin as well. Here thrusting of crystalline basement with its Mesozoic cover was south-directed. The various Alpine nappe piles led to the amalgamation of very different rock types: continental and oceanic basement rocks, shallow marine carbonates, deep marine clastics and radiolarian chert to name the most important. Landforms and landscapes reflect these differences, in addition to the landforms created by fluvial and glacial erosion

Top of Europe: the Finsteraarhorn–Jungfrau glacier landscape

The Finsteraarhorn, the highest peak in the Bernese Alps, and the Jungfrau, renowned for its cog railway that attracts a high number of tourists each year, are together in the heart of a high mountain glacier landscape. The Unteraar Glacier with an east-oriented and extensively debris-covered tongue has, since the eighteen/nineteenth century, been the cradle of glacier research (e.g. L. Agassiz). In turn, Lower Grindelwald Glacier became historically the best-documented Swiss valley glacier, thanks to its accessible, low-altitude ice-front position. A wealth of high-quality depictions by top artists (e.g. C. Wolf and S. Birmann) have allowed the reconstruction of the Little Ice Age (LIA) glacier fluctuations in a uniquely precise way. The Upper Lauterbrunnen Valley, dominated on both sides by huge steep rock walls with a great number of waterfalls, hosts smaller glaciers and a collection of moraines in the valley bottom. Since the end of the LIA, all the glaciers have been melting back, with a dramatic increase in recent years. The Lower Grindelwald Glacier, for instance, shows a reduction of the ice volume by 50% since the end of the LIA. By the end of the twenty-firstc entury, the Finsteraarhorn–Jungfrau landscape will no longer exist in the form it has been renowned for over the last centuries