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101-578: In the north and northwest, the Swiss Plateau is sharply delimited geographically and geologically by the Jura Mountains . In the south, there is no clear border with the Alps . Usually, the rising of the terrain to altitudes above 1500 metres AMSL (lime Alps, partly sub-alpine molasse), which is very abrupt in certain places, is taken as a criterion for delimitation. Occasionally the regions of

202-535: A characteristic fabric . All three types may melt again, and when this happens, new magma is formed, from which an igneous rock may once again solidify. Organic matter, such as coal, bitumen, oil, and natural gas, is linked mainly to organic-rich sedimentary rocks. To study all three types of rock, geologists evaluate the minerals of which they are composed and their other physical properties, such as texture and fabric . Geologists also study unlithified materials (referred to as superficial deposits ) that lie above

303-485: A petrographic microscope , where the minerals can be identified through their different properties in plane-polarized and cross-polarized light, including their birefringence , pleochroism , twinning , and interference properties with a conoscopic lens . In the electron microprobe, individual locations are analyzed for their exact chemical compositions and variation in composition within individual crystals. Stable and radioactive isotope studies provide insight into

404-434: A definite homogeneous chemical composition and an ordered atomic arrangement. Each mineral has distinct physical properties, and there are many tests to determine each of them. Minerals are often identified through these tests. The specimens can be tested for: A rock is any naturally occurring solid mass or aggregate of minerals or mineraloids . Most research in geology is associated with the study of rocks, as they provide

505-408: A dense road network. With the rise of industrialisation in the early 19th century, cities became more and more important. In 1860 a drastic population growth of the cities started which lasted for about 100 years. In the 1970s, however, outmigration from the cities started. The municipalities surrounding the cities grew disproportionately, whereas the cities themselves lost inhabitants. In recent times

606-627: A length of less than a meter. Rocks at the depth to be ductilely stretched are often also metamorphosed. These stretched rocks can also pinch into lenses, known as boudins , after the French word for "sausage" because of their visual similarity. Where rock units slide past one another, strike-slip faults develop in shallow regions, and become shear zones at deeper depths where the rocks deform ductilely. The addition of new rock units, both depositionally and intrusively, often occurs during deformation. Faulting and other deformational processes result in

707-452: A means to provide information about geological history and the timing of geological events. The principle of uniformitarianism states that the geological processes observed in operation that modify the Earth's crust at present have worked in much the same way over geological time. A fundamental principle of geology advanced by the 18th-century Scottish physician and geologist James Hutton

808-608: A number of fields, laboratory, and numerical modeling methods to decipher Earth history and to understand the processes that occur on and inside the Earth. In typical geological investigations, geologists use primary information related to petrology (the study of rocks), stratigraphy (the study of sedimentary layers), and structural geology (the study of positions of rock units and their deformation). In many cases, geologists also study modern soils, rivers , landscapes , and glaciers ; investigate past and current life and biogeochemical pathways, and use geophysical methods to investigate

909-451: A sedimentary rock. Sedimentary rocks are mainly divided into four categories: sandstone, shale, carbonate, and evaporite. This group of classifications focuses partly on the size of sedimentary particles (sandstone and shale), and partly on mineralogy and formation processes (carbonation and evaporation). Igneous and sedimentary rocks can then be turned into metamorphic rocks by heat and pressure that change its mineral content, resulting in

1010-499: A single environment and do not necessarily occur in a single order. The Hawaiian Islands , for example, consist almost entirely of layered basaltic lava flows. The sedimentary sequences of the mid-continental United States and the Grand Canyon in the southwestern United States contain almost-undeformed stacks of sedimentary rocks that have remained in place since Cambrian time. Other areas are much more geologically complex. In

1111-473: A small airport, Bern Belpmoos Airport . Härkingen respectively Niederbipp and Zürich are scheduled as one of the eight hubs of the proposed Cargo Sous Terrain , an underground cargo transport system those first phase of about 70 kilometres (43 mi) is planned by the early 2030s. Compared to the Swiss Alps, the plateau, and especially the rural plateau, is less geared towards tourism. It serves as

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1212-632: A transit region. Visitors mainly come to see the major towns and cities with their historical sights and attractions, especially the Old Towns of Bern and Lucerne, but also Zürich, Biel/Bienne, St. Gallen, Fribourg, Geneva and Lausanne. An important natural touristic attraction is the Rhine Fall near Schaffhausen. The lakes also attract tourists, and then there are several spa towns , Baden , Schinznach-Bad , Yverdon-les-Bains and Zurzach , thanks to their hydrothermal vents . Zürich Wilderness Park

1313-417: A valley or canyon empties out onto a flatter wider plain. Outwash fans form when melt-water from a retreating glacier deposits transported sediment in the shape of a fan along the outwash plain. Glaciers contain large amounts of sediment (i.e. sand, silt, clay) that is gathered through glacial erosional processes such as abrasion between the glacier and the underlying rocks, and through glacial plucking . As

1414-400: A variety of applications. Dating of lava and volcanic ash layers found within a stratigraphic sequence can provide absolute age data for sedimentary rock units that do not contain radioactive isotopes and calibrate relative dating techniques. These methods can also be used to determine ages of pluton emplacement. Thermochemical techniques can be used to determine temperature profiles within

1515-655: Is crystalline basement which outcrops in the central crystalline Alps as well as in the Black Forest and the Vosges mountain range but forms a deep geosyncline in the Swiss Plateau and in the Jura (see also Jurassic ). Around 2500 – 3000 metres below the surface, but considerably deeper near the Alps, the drillings have hit the crystalline basement. It is covered by unfolded strata of Mesozoic sediments , which are part of

1616-552: Is viticulture . Grassland with dairy farming and beef production is predominant in the eastern plateau and in the higher regions. Especially in the Thurgau, fruit (apples) is important. The forests in the Swiss Plateau are used in forestry. There are many Norway Spruce forestations, often in monoculture because of their valuable timber. With respect to industry , the plateau is the most important region of Switzerland. The traditional textile industries are situated especially in

1717-479: Is 20 °C, alongside the southern edge of the Jura it is 18 – 20 °C, and in higher regions 16 – 18 °C. With regard to mean sunshine duration, the Lake Geneva region is again advantaged with more than 1900 hours, whereas in the rest of the Swiss Plateau, it is between 1600 (especially in the east) and 1900 hours. The annual average rainfall is between 800 millimetres near the Jura, 1200 millimetres in

1818-557: Is French-speaking. The language border has been stable for many centuries even though it falls neither on a geographical nor on a political delimitation. It passes from Biel/Bienne over Murten and Fribourg to the Fribourg Alps. The cities of Biel/Bienne, Murten and Fribourg are officially bilingual. Localities along the language border usually use both names, the German and the French one, officially interchangeable. Thanks to

1919-419: Is a branch of natural science concerned with the Earth and other astronomical objects , the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences , including hydrology . It is integrated with Earth system science and planetary science . Geology describes the structure of the Earth on and beneath its surface and

2020-422: Is accomplished in two primary ways: through faulting and folding . In the shallow crust, where brittle deformation can occur, thrust faults form, which causes the deeper rock to move on top of the shallower rock. Because deeper rock is often older, as noted by the principle of superposition , this can result in older rocks moving on top of younger ones. Movement along faults can result in folding, either because

2121-460: Is an intimate coupling between the movement of the plates on the surface and the convection of the mantle (that is, the heat transfer caused by the slow movement of ductile mantle rock). Thus, oceanic parts of plates and the adjoining mantle convection currents always move in the same direction – because the oceanic lithosphere is actually the rigid upper thermal boundary layer of the convecting mantle. This coupling between rigid plates moving on

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2222-568: Is highly developed. The most important transversal, so to speak the backbone of the Swiss Plateau, is the A1 motorway that connects all the big cities going from Geneva over Lausanne, Bern, Zürich and Winterthur to St. Gallen. The A2, the Swiss north-south axis, crosses the plateau from Olten to Luzern. The railway network is very dense. All major cities are connected, and between Olten and Lausanne, there are two main lines: One passing over Bern and Fribourg,

2323-433: Is horizontal). The principle of superposition states that a sedimentary rock layer in a tectonically undisturbed sequence is younger than the one beneath it and older than the one above it. Logically a younger layer cannot slip beneath a layer previously deposited. This principle allows sedimentary layers to be viewed as a form of the vertical timeline, a partial or complete record of the time elapsed from deposition of

2424-616: Is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources , understanding natural hazards , remediating environmental problems, and providing insights into past climate change . Geology is a major academic discipline , and it is central to geological engineering and plays an important role in geotechnical engineering . The majority of geological data comes from research on solid Earth materials. Meteorites and other extraterrestrial natural materials are also studied by geological methods. Minerals are naturally occurring elements and compounds with

2525-484: Is primarily accomplished through normal faulting and through the ductile stretching and thinning. Normal faults drop rock units that are higher below those that are lower. This typically results in younger units ending up below older units. Stretching of units can result in their thinning. In fact, at one location within the Maria Fold and Thrust Belt , the entire sedimentary sequence of the Grand Canyon appears over

2626-688: Is stamped by the Gros-de-Vaud plateau (up to 600 meters AMSL) and the Jorat molasse hills (up to 900 meters AMSL) but is sometimes intersected by deep valleys. Only near the Jura, there is an almost continuous dip consisting of the Venoge and the Orbe valleys which are separated by the Mormont hill, the main watershed between Rhône and Rhine, at only 500 m AMSL. The Seeland ('lake land'), characterized by

2727-568: Is that "the present is the key to the past." In Hutton's words: "the past history of our globe must be explained by what can be seen to be happening now." The principle of intrusive relationships concerns crosscutting intrusions. In geology, when an igneous intrusion cuts across a formation of sedimentary rock , it can be determined that the igneous intrusion is younger than the sedimentary rock. Different types of intrusions include stocks, laccoliths , batholiths , sills and dikes . The principle of cross-cutting relationships pertains to

2828-530: Is the largest mixed deciduous and coniferous forest in the plateau, and includes the Sihl forest and Langenberg, the oldest Swiss wildlife park. The park covers approximately 12 square kilometres (4.6 sq mi). 47°07′N 7°22′E  /  47.117°N 7.367°E  / 47.117; 7.367 Geology Geology (from Ancient Greek γῆ ( gê )  'earth' and λoγία ( -logía )  'study of, discourse')

2929-523: Is used for geologically young materials containing organic carbon . The geology of an area changes through time as rock units are deposited and inserted, and deformational processes alter their shapes and locations. Rock units are first emplaced either by deposition onto the surface or intrusion into the overlying rock . Deposition can occur when sediments settle onto the surface of the Earth and later lithify into sedimentary rock, or when as volcanic material such as volcanic ash or lava flows blanket

3030-720: The Helvetic nappes . Its depth gradually decreases from about 2.5 km in the west to 0.8 km in the east. These layers, like the ones of the Jura Mountains, were deposited in a relatively shallow sea, the Tethys Ocean . Above the Mesozoic layers, is the Molasse , consisting of conglomerate , sandstone , marl and shale . The uppermost layer consists of gravel and glacial sediments that have been transported by

3131-470: The Lake Baldegg . Another reminder of the glaciation are glacial erratics which are found all over the Swiss Plateau. These rocks, sometimes of enormous size, are of alien stones, mostly granite and gneiss from the central crystalline Alps. Taken together, they were one of the clues that led to the substantiation of the glaciation theory in the 19th century since transport by water or by volcanism

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3232-462: The Rhine advanced sometimes as well until the Jura. The glaciers formed the land by erosion, but also by base moraines (very fine stone meal) often several meters thick, and by the meltwater streams depositing gravel. Traces of the older Günz and Mindel glaciation are only left in a few places because most have been removed or transferred by the later glaciations. The greatest extension was reached by

3333-842: The Suhre , the Seetal , the Reuss and the Limmat ). The Rhine Glacier has mostly left traces that trend west: The eastern Swiss Plateau of the Thur Valley and Lake Constance. In certain places, there are characteristic drumlins of the base moraine, often clustered, especially in the highlands of Zürich, in the Hirzel region, in the Lake Constance region and between the Reuss Valley and

3434-506: The bedrock . This study is often known as Quaternary geology , after the Quaternary period of geologic history, which is the most recent period of geologic time. Magma is the original unlithified source of all igneous rocks . The active flow of molten rock is closely studied in volcanology , and igneous petrology aims to determine the history of igneous rocks from their original molten source to their final crystallization. In

3535-512: The geochemical evolution of rock units. Petrologists can also use fluid inclusion data and perform high temperature and pressure physical experiments to understand the temperatures and pressures at which different mineral phases appear, and how they change through igneous and metamorphic processes. This research can be extrapolated to the field to understand metamorphic processes and the conditions of crystallization of igneous rocks. This work can also help to explain processes that occur within

3636-452: The glaciers of the ice ages . Geologically the most important layer of the Swiss Plateau is the thick molasse sequence that accumulated at the border of the Alps due to the rapid erosion of the concurrently uplifted mountains. The thickness of the molasse increases from west to east (at the same distance from the Alps). The former alpine rivers built huge fans of sediment at the foot of

3737-402: The mantle below (separated within itself by seismic discontinuities at 410 and 660 kilometers), and the outer core and inner core below that. More recently, seismologists have been able to create detailed images of wave speeds inside the earth in the same way a doctor images a body in a CT scan . These images have led to a much more detailed view of the interior of the Earth, and have replaced

3838-420: The terminus of the glacier. The outwash , the sediment transported and deposited by the meltwater and that makes up the fan, is usually poorly sorted due to the short distance traveled before being deposited. Outwash fans typically form from valley glaciers flowing downhill in the mountains. Thus, outwash fans are usually found in colder environments where glaciers are more prevalent and are often located where

3939-440: The 1960s, it was discovered that the Earth's lithosphere , which includes the crust and rigid uppermost portion of the upper mantle , is separated into tectonic plates that move across the plastically deforming, solid, upper mantle, which is called the asthenosphere . This theory is supported by several types of observations, including seafloor spreading and the global distribution of mountain terrain and seismicity. There

4040-685: The Aare orifice and Schaffhausen, the predominant trees are oak , tilia and maple . Humans began to settle the plateau in the Neolithic , starting with the banks of lakes and rivers. Major oppida were built after the Celts appeared in the 3rd century BC. Urban settlements with stone houses were built during the Roman Empire . The Swiss Plateau became a part of the Roman Empire in 15 BC when

4141-469: The Alps and the Jura can have the brightest sunshine. Typical for the high fog is the bise , a cold wind from the northeast. Since it is channelled by the Swiss Plateau narrowing in the southwest, it reaches its major strength in the Lake Geneva region where wind speeds of 60 km/h with top speeds of more than 100 km/h are usual in typical bise weather. The regions near the Alps of the central and eastern plateau sometimes have temperature rises due to

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4242-510: The Alps. The central Swiss Plateau is characterised by a number of ranges and broad valleys, some of them with lakes, that run northwest. The last of them is the Albis range, which together with the Heitersberg range forms a bar from the Alps to the Jura that the major transportations bypass only in a few places, mostly in tunnels. The eastern Swiss Plateau is structured by the valleys of

4343-424: The Earth, such as subduction and magma chamber evolution. Structural geologists use microscopic analysis of oriented thin sections of geological samples to observe the fabric within the rocks, which gives information about strain within the crystalline structure of the rocks. They also plot and combine measurements of geological structures to better understand the orientations of faults and folds to reconstruct

4444-552: The German and Austrian Pre-Alps . Within Switzerland, the Swiss Plateau has a length of about 300 kilometres (190 mi), and its width increases from the west to the east: In the Geneva region, it is about 30 kilometres (19 mi), at Bern about 50 kilometres (31 mi) and in eastern Switzerland about 70 kilometres (43 mi). Many cantons of Switzerland include a part in the Swiss Plateau. Entirely situated within

4545-484: The Grand Canyon in the southwestern United States being a very visible example, the lower rock units were metamorphosed and deformed, and then deformation ended and the upper, undeformed units were deposited. Although any amount of rock emplacement and rock deformation can occur, and they can occur any number of times, these concepts provide a guide to understanding the geological history of an area. Geologists use

4646-471: The Ice Age glaciers, there is plenty of gravel and clay. The gravel digging in the Ice Age gravel terraces all over the Swiss Plateau covers the demands of the construction industry. Numerous hydroelectric power plants in the rivers produce electricity. All four Swiss nuclear power plants are situated on the plateau. Because of the comparatively easy topography and the dense population, the transport network

4747-468: The Jura, clays and marl. During the Tertiary orogenic uplift , around 60 – 40 million years ago, the area of today's Swiss Plateau was a Karst plateau somewhat inclined to the south. Through processes of rising and lowering that were brought by the folding of the Alps, the area was twice flooded by a sea. The corresponding sediments are distinguished as sea molasse and freshwater molasse, even though

4848-855: The Limmat (including Lake Zurich ), the Glatt , the Töss , the Murg , the Thur , and the Sitter . Between them there are hill countries, in the canton of Thurgau also the broad molasse ranges of Seerücken (lit.: 'back of the lake') and Ottenberg north of the Thur, and the hilly ranges between the Thur and the Murg. This area is colloquially also known as Mostindien (lit.: 'Cider India'). Two hill countries get out of line with

4949-611: The Murten, Neuchâtel and Biel lakes, represents the biggest plain of the Swiss Plateau, though it is also interrupted by isolated molasse ranges. In the east, it is neighboured by various hill countries the height of which decreases to the north. Another major plain is the Wasseramt where the Emme runs. In a broad valley alongside the Jura, the Aare collects all the rivers that come down from

5050-513: The Romans occupied the land of the Helvetii under the reign of Augustus , and it remained Roman until the end of the 3rd century. The most important Roman cities in the Swiss Plateau were Auenticum (today Avenches ), Vindonissa (today Windisch ), Colonia Iulia Equestris or, by its Celtic name, and Noviodunum (today Nyon ). They were well connected by a net of Roman roads . After

5151-412: The Swiss Plateau are the cantons of Zürich , Thurgau and Geneva ; mostly situated within the Swiss Plateau are the cantons of Lucerne , Aargau , Solothurn , Bern , Fribourg and Vaud ; small portions of the Swiss Plateau are situated in the cantons of Neuchâtel , Zug , Schwyz , St. Gallen and Schaffhausen . The geological layers of the Swiss Plateau are relatively well known. The base level

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5252-537: The beginning of the 20th century, advancement in geological science was facilitated by the ability to obtain accurate absolute dates to geological events using radioactive isotopes and other methods. This changed the understanding of geological time. Previously, geologists could only use fossils and stratigraphic correlation to date sections of rock relative to one another. With isotopic dates, it became possible to assign absolute ages to rock units, and these absolute dates could be applied to fossil sequences in which there

5353-514: The central and eastern regions. During the last decades, however, it lost importance. Today's most important industries are the machine industry, the automotive industry, the electrical industry, the fine & micro mechanical, watch & electronic industries, next to the optical and metal construction. The food industry processes domestic as well as foreign produces. Furthermore, wood processing and paper converting are also important. Like all of Switzerland, there are few mineral resources. Thanks to

5454-515: The creation of topographic gradients, causing material on the rock unit that is increasing in elevation to be eroded by hillslopes and channels. These sediments are deposited on the rock unit that is going down. Continual motion along the fault maintains the topographic gradient in spite of the movement of sediment and continues to create accommodation space for the material to deposit. Deformational events are often also associated with volcanism and igneous activity. Volcanic ashes and lavas accumulate on

5555-437: The crust, the uplift of mountain ranges, and paleo-topography. Fractionation of the lanthanide series elements is used to compute ages since rocks were removed from the mantle. Other methods are used for more recent events. Optically stimulated luminescence and cosmogenic radionuclide dating are used to date surfaces and/or erosion rates. Dendrochronology can also be used for the dating of landscapes. Radiocarbon dating

5656-570: The fault is a normal fault or a thrust fault . The principle of inclusions and components states that, with sedimentary rocks, if inclusions (or clasts ) are found in a formation, then the inclusions must be older than the formation that contains them. For example, in sedimentary rocks, it is common for gravel from an older formation to be ripped up and included in a newer layer. A similar situation with igneous rocks occurs when xenoliths are found. These foreign bodies are picked up as magma or lava flows, and are incorporated, later to cool in

5757-403: The faults are not planar or because rock layers are dragged along, forming drag folds as slip occurs along the fault. Deeper in the Earth, rocks behave plastically and fold instead of faulting. These folds can either be those where the material in the center of the fold buckles upwards, creating " antiforms ", or where it buckles downwards, creating " synforms ". If the tops of the rock units within

5858-543: The favourable climate and fertile grounds, the lower western plateau is the most important agricultural region of Switzerland . The most important cultures are wheat , barley , maize , sugar beet and potato ; especially in the Seeland , vegetables are very important, too. Along the northern shores of the lakes of Geneva , Neuchâtel , Bienne , Morat , as well as in the Zürich Weinland and Klettgau , there

5959-483: The folds remain pointing upwards, they are called anticlines and synclines , respectively. If some of the units in the fold are facing downward, the structure is called an overturned anticline or syncline, and if all of the rock units are overturned or the correct up-direction is unknown, they are simply called by the most general terms, antiforms, and synforms. Even higher pressures and temperatures during horizontal shortening can cause both folding and metamorphism of

6060-404: The formation of faults and the age of the sequences through which they cut. Faults are younger than the rocks they cut; accordingly, if a fault is found that penetrates some formations but not those on top of it, then the formations that were cut are older than the fault, and the ones that are not cut must be younger than the fault. Finding the key bed in these situations may help determine whether

6161-579: The geological history of the Earth as a whole. One aspect is to demonstrate the age of the Earth . Geology provides evidence for plate tectonics , the evolutionary history of life , and the Earth's past climates . Geologists broadly study the properties and processes of Earth and other terrestrial planets. Geologists use a wide variety of methods to understand the Earth's structure and evolution, including fieldwork , rock description , geophysical techniques , chemical analysis , physical experiments , and numerical modelling . In practical terms, geology

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6262-415: The glacier acts as a natural sorter. Finer materials such as silt and clay are redeposited further away from the glacier, while larger sediments such as pebbles and rocks remain closest to the glacier. Because the sediments rely on melt water for transportation, the ablation rate directly affects the development of an outwash fan. Other factors that affect fan morphology include the slope of the outwash fan and

6363-436: The glacier begins to retreat and ablation increases, the melting ice deposits sediments from a single source at the terminus of the glacier. Melt-water from the glacier forming a braided stream then carries the sediment away and redeposits it further away from the glacier. The sedimentation of the outwash fan is often poorly sorted due to the short distance covered by the transported sediment, however, water runoff from

6464-615: The glaciers of the Riss glaciation, when the entire Swiss Plateau was covered with ice except for the Napf and Töss regions. Most notable are the traces of the Würm glaciation about 15 000 years ago. The end moraines of different glacial retreats have been conserved. A look at a map still reveals the directions where the ice age glaciers ran. The farthest expansion of the Rhône Glacier to

6565-516: The glaciers receded to the high alps (sometimes more than today) and subtropical vegetation spread in the plateau. During the ice ages, the Rhône glacier split into two branches when leaving the Alps, covering the whole western Swiss Plateau and reaching today's regions of Solothurn and Aarau . In the region of Bern, it merged with the Aar Glacier . The glaciers of the Reuss , the Limmat and

6666-631: The higher Swiss Plateau, especially the hills of the canton of Fribourg , the Napf region, the Töss region, the (lower) Toggenburg , and parts of the Appenzell region are considered to form the Swiss Alpine foreland in a narrow sense. However, if a division into the three main regions Jura Mountains, Swiss Plateau and Alps is considered, the Alpine foreland belongs clearly to the Swiss Plateau. In

6767-511: The higher regions and 1400 millimetres at the edge of the Alps. The driest regions of the plateau are in the lee of the High Jura between Morges and Neuchâtel. In the warmest regions at the lakes of Geneva and Neuchâtel, there are less than 20 days with a snow cover, whereas, in the rest of the plateau, it is between 20 and 40, depending on the height. In the winter half-year, the air on the Swiss Plateau can stay still, with little exchange for

6868-405: The higher terraces of Riss glaciation terraces. Sometimes, there is also gravel from older glaciations. Even though the Swiss Plateau forms a basin, it is by no means a flat territory, but depending on the region, it has a manifold structure. Important elements are the two big lakes, Lake Geneva and Lake Constance that delimit the Swiss Plateau in the southwest and the northeast. The western plateau

6969-420: The history of rock deformation in the area. In addition, they perform analog and numerical experiments of rock deformation in large and small settings. Outwash fans An outwash fan is a fan-shaped body of sediments deposited by braided streams from a melting glacier . Sediment locked within the ice of the glacier gets transported by the streams of meltwater, and deposits on the outwash plain, at

7070-423: The internal composition and structure of the Earth. Seismologists can use the arrival times of seismic waves to image the interior of the Earth. Early advances in this field showed the existence of a liquid outer core (where shear waves were not able to propagate) and a dense solid inner core . These advances led to the development of a layered model of the Earth, with a lithosphere (including crust) on top,

7171-464: The later end of the scale, it is marked by the present day (in the Holocene epoch ). The following five timelines show the geologic time scale to scale. The first shows the entire time from the formation of the Earth to the present, but this gives little space for the most recent eon. The second timeline shows an expanded view of the most recent eon. In a similar way, the most recent era is expanded in

7272-407: The latter consists rather of fluvial and eolian sediments (a kind of mainland molasse ). In the following time, especially the western part of the plateau was again significantly risen, so that in this area, the sediments of the upper sweetwater molasse and the upper sea molasse have been largely eroded. A characteristic of the sea molasses is fossil snails, shells and shark teeth, whereas in

7373-454: The lowest layer to deposition of the highest bed. The principle of faunal succession is based on the appearance of fossils in sedimentary rocks. As organisms exist during the same period throughout the world, their presence or (sometimes) absence provides a relative age of the formations where they appear. Based on principles that William Smith laid out almost a hundred years before the publication of Charles Darwin 's theory of evolution ,

7474-497: The mantle and show the crystallographic structures expected in the inner core of the Earth. The geological time scale encompasses the history of the Earth. It is bracketed at the earliest by the dates of the first Solar System material at 4.567 Ga (or 4.567 billion years ago) and the formation of the Earth at 4.54 Ga (4.54 billion years), which is the beginning of the Hadean eon  – a division of geological time. At

7575-405: The matrix. As a result, xenoliths are older than the rock that contains them. The principle of original horizontality states that the deposition of sediments occurs as essentially horizontal beds. Observation of modern marine and non-marine sediments in a wide variety of environments supports this generalization (although cross-bedding is inclined, the overall orientation of cross-bedded units

7676-550: The mentioned landscapes: The Napf region (with 1408 me AMSL the highest point of the Swiss Plateau) and the Töss region (up to 1300 meters AMSL), both of them the remains of Tertiary conglomerate sediment fans. Since they were not glaciated, they have only been eroded by water, resulting in a dense net of deep, narrow valleys. The Swiss Plateau is situated within a transition zone between humid oceanic climate and continental temperate climate. The predominant wind comes from

7777-503: The most populous areas. Other densely populated areas are located at the south edge next to the Jura, and the agglomerations of Lucerne , Winterthur and St. Gallen . Regions of the higher Swiss Plateau like the Jorat region, the Napf region or the Töss region are comparatively scarcely populated with little farming villages and scattered farms. A majority is German-speaking, though the west

7878-668: The mountains. The most important examples are the Napf fan and the Hörnli fan; other sedimentary fans exist in the Rigi region, in the Schwarzenburg region and in the region between the eastern lake Geneva and the middle reaches of the Saane/Sarine . The eroded material has been sorted by grain size. The coarse material was predominantly deposited near the Alps. In the middle of the plateau, there are finer sandstones and near

7979-617: The northeast is indicated by way the western Swiss Plateau valleys trend: The valleys of the Broye and the Glâne as well as Lake Murten , Lake Neuchâtel , and Lake Biel that trend all northeast, parallel to the Jura and to the Alps . The glaciers of the Reuss and the Limmat have carved the valleys of the central Swiss Plateau that trend northwest (among others including the valleys of the Wigger ,

8080-455: The other passing over the edge of the Jura with Solothurn, Biel, Neuchâtel and Yverdon-les-Bains. The train ride from Zürich to Bern takes one hour; crossing the entire Swiss Plateau from St. Gallen to Geneva takes four hours. The two most important Swiss airports are situated on the plateau, Zurich Airport and Geneva Cointrin Airport . The de facto capital of Switzerland, Bern, has only

8181-502: The outmigration has moved farther away from the cities. Even though the Swiss Plateau takes only about 30% of the surface of Switzerland, 5 million people live there, which constitutes more than two-thirds of the Swiss population. The population density is 380 people per square kilometre. All the Swiss cities with more than 50 000 inhabitants except Basel and Lugano are situated in the plateau, especially Bern , Geneva , Lausanne and Zürich . The agglomerations of these cities are

8282-413: The primary record of the majority of the geological history of the Earth. There are three major types of rock: igneous , sedimentary , and metamorphic . The rock cycle illustrates the relationships among them (see diagram). When a rock solidifies or crystallizes from melt ( magma or lava ), it is an igneous rock . This rock can be weathered and eroded , then redeposited and lithified into

8383-569: The principles of succession developed independently of evolutionary thought. The principle becomes quite complex, however, given the uncertainties of fossilization, localization of fossil types due to lateral changes in habitat ( facies change in sedimentary strata), and that not all fossils formed globally at the same time. Geologists also use methods to determine the absolute age of rock samples and geological events. These dates are useful on their own and may also be used in conjunction with relative dating methods or to calibrate relative methods. At

8484-423: The processes that have shaped that structure. Geologists study the mineralogical composition of rocks in order to get insight into their history of formation. Geology determines the relative ages of rocks found at a given location; geochemistry (a branch of geology) determines their absolute ages . By combining various petrological, crystallographic, and paleontological tools, geologists are able to chronicle

8585-421: The rest of the atmosphere, building a lake of cold air on the plateau and often a ceiling of high fog. The clouds look like an ocean of fog when seen from above, (usually around 800m) and hence are called the 'nebelmeer'. This weather is called inversion because the temperature below the fog is lower than the temperature above. Sometimes, it lasts for days or even for weeks, during which the neighbouring regions of

8686-523: The retreat of the Roman Empire, the romanized Burgundians occupied the western Swiss Plateau, while the Alamanni settled in the central and eastern portions. The language border between French and German dialects originated in this contrast. During the Middle Ages many towns were founded, especially in the climatically more favoured lower plateau. In 1500 there were already 130 towns, connected by

8787-428: The rocks. This metamorphism causes changes in the mineral composition of the rocks; creates a foliation , or planar surface, that is related to mineral growth under stress. This can remove signs of the original textures of the rocks, such as bedding in sedimentary rocks, flow features of lavas , and crystal patterns in crystalline rocks . Extension causes the rock units as a whole to become longer and thinner. This

8888-433: The simplified layered model with a much more dynamic model. Mineralogists have been able to use the pressure and temperature data from the seismic and modeling studies alongside knowledge of the elemental composition of the Earth to reproduce these conditions in experimental settings and measure changes within the crystal structure. These studies explain the chemical changes associated with the major seismic discontinuities in

8989-508: The southwest, the Swiss Plateau is confined by Lake Geneva , in the northeast, by Lake Constance and the Rhine . Geologically, the Swiss Plateau is part of a larger basin that extends beyond the border of Switzerland. At its southwestern end, in France , the plateau, in the Genevois , ends at Chambéry where Jura and Alps meet. On the other side of Lake Constance, the plateau continues in

9090-532: The southwestern United States, sedimentary, volcanic, and intrusive rocks have been metamorphosed, faulted, foliated, and folded. Even older rocks, such as the Acasta gneiss of the Slave craton in northwestern Canada , the oldest known rock in the world have been metamorphosed to the point where their origin is indiscernible without laboratory analysis. In addition, these processes can occur in stages. In many places,

9191-550: The subsurface. Sub-specialities of geology may distinguish endogenous and exogenous geology. Geological field work varies depending on the task at hand. Typical fieldwork could consist of: In addition to identifying rocks in the field ( lithology ), petrologists identify rock samples in the laboratory. Two of the primary methods for identifying rocks in the laboratory are through optical microscopy and by using an electron microprobe . In an optical mineralogy analysis, petrologists analyze thin sections of rock samples using

9292-407: The surface of the Earth and the convecting mantle is called plate tectonics . The development of plate tectonics has provided a physical basis for many observations of the solid Earth . Long linear regions of geological features are explained as plate boundaries: Plate tectonics has provided a mechanism for Alfred Wegener 's theory of continental drift , in which the continents move across

9393-488: The surface of the Earth over geological time. They also provided a driving force for crustal deformation, and a new setting for the observations of structural geology. The power of the theory of plate tectonics lies in its ability to combine all of these observations into a single theory of how the lithosphere moves over the convecting mantle. Advances in seismology , computer modeling , and mineralogy and crystallography at high temperatures and pressures give insights into

9494-479: The surface, and igneous intrusions enter from below. Dikes , long, planar igneous intrusions, enter along cracks, and therefore often form in large numbers in areas that are being actively deformed. This can result in the emplacement of dike swarms , such as those that are observable across the Canadian shield, or rings of dikes around the lava tube of a volcano. All of these processes do not necessarily occur in

9595-742: The surface. Igneous intrusions such as batholiths , laccoliths , dikes , and sills , push upwards into the overlying rock, and crystallize as they intrude. After the initial sequence of rocks has been deposited, the rock units can be deformed and/or metamorphosed . Deformation typically occurs as a result of horizontal shortening, horizontal extension , or side-to-side ( strike-slip ) motion. These structural regimes broadly relate to convergent boundaries , divergent boundaries , and transform boundaries, respectively, between tectonic plates. When rock units are placed under horizontal compression , they shorten and become thicker. Because rock units, other than muds, do not significantly change in volume , this

9696-418: The sweetwater molasse, fossils of typical land mammals and former subtropical vegetation (for instance palm leaves) are found. The contemporary landscape of the Swiss Plateau has been shaped by the ice age glaciers. During all the known alpine glaciations ( Günz glaciation , Mindel glaciation , Riss glaciation and Würm glaciation ), huge glaciers penetrated the Swiss Plateau. During the warm interglacials,

9797-407: The third timeline, the most recent period is expanded in the fourth timeline, and the most recent epoch is expanded in the fifth timeline. Horizontal scale is Millions of years (above timelines) / Thousands of years (below timeline) Epochs: Methods for relative dating were developed when geology first emerged as a natural science . Geologists still use the following principles today as

9898-472: The warm foehn wind . The dominating vegetation in the Swiss Plateau is a mixed broadleaf forest with European beeches and silver firs . For forestry , there are major plantations of Norway spruces in many places, though the Norway spruce naturally only grows in the mountains. In certain favoured spots that are warmer and drier, in the Lake Geneva region, in the Seeland and in the northern plateau between

9999-428: The west. In the lower plateau, the mean annual temperature is about 9 – 10 °C. In January, the Lake Geneva region and the watersides of lake Neuchâtel and Lake Biel have the highest mean temperature of about +1 °C. At the same height as AMSL, the temperature is decreasing towards the east. In the Lake Constance region, the mean temperature of the coldest month is -1 °C. In July, the mean temperature of Geneva

10100-615: Was datable material, converting the old relative ages into new absolute ages. For many geological applications, isotope ratios of radioactive elements are measured in minerals that give the amount of time that has passed since a rock passed through its particular closure temperature , the point at which different radiometric isotopes stop diffusing into and out of the crystal lattice . These are used in geochronologic and thermochronologic studies. Common methods include uranium–lead dating , potassium–argon dating , argon–argon dating and uranium–thorium dating . These methods are used for

10201-409: Was physically impossible. Gravel deposits in the bottoms of the valleys are another testimonial of the glaciation. During the advances and withdrawals of the glaciers, gravel layers were deposited in the valleys, sometimes quite thick, though most of it eroded in the subsequent interglacials . Therefore, many valleys have characteristic terraces, the lower terraces consisting of Würm glaciation gravel,

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