# Lithology: type of rocks A thematic map of the Atlas of Switzerland, the national atlas published by ETH Zurich. The map is drawn in the browser; this file describes it and lists its variants and links, but not the data values shown on the map. - Map: https://atlasderschweiz.ch/en/theme/lithology-type-of-rocks/ - Short title: Lithology - Map id: 165 - Categories: Nature and Environment › Geology and raw materials › Geology and tectonics - Keywords: Geology - Published: 2016-04-12 - Last revised: 2019-02-26 - Content language: English - Other languages: [Deutsch](https://atlasderschweiz.ch/de/thema/lithologie-art-der-gesteine.md), [Français](https://atlasderschweiz.ch/fr/theme/lithologie-type-de-roches.md), [Italiano](https://atlasderschweiz.ch/it/tema/litologia-tipo-di-rocce.md) ## Description The cartographic representation of lithology shows the classification of rock series according to geotechnical criteria. The classification is based on lithological, mineralogical, chemical and physical characteristics of the rocks. This classification is closely linked to the use and utilisation of rocks as raw materials or construction materials. From this type of representation, important basic geotechnical data can be derived which are highly significant for the evaluation of the geological ground in relation to construction projects or the use of rocks as construction materials (e.g. homogeneity and hardness of the materials, chemical properties, susceptibility to weathering, etc.). Geotechnical maps represent important decision-making tools for projects involving the planning and execution of all types of buildings and structures. As opposed to geological maps, which subdivide the rock basement according to age (stratigraphy) and type of formation, the formation time frame of the rocks does not play a role in the lithological representation. Rocks with different ages are included in the same unit if they have similar characteristics or technical parameters. Thus, the lithological representation of the underground can differ significantly from the geological interpretation. In the generalised presentation, all of the rocks are subdivided into 25 groups according to the following criteria: formation, mineralogical composition, grain size and crystallinity: - *Silts, Sands: *Loose rock/sediments; the grain size of the components is between 0.002 and 2 mm. - *Sands, Gravels, Cobbles: *Loose rock/sediments; the grain size of the components is between 0.2 and 256 mm. - *Blocks, Cobbles: *Loose rock/sediments, whose components are larger than 256 mm. - *Marl: *Intact rock/sediments, formed of variable amounts of clay and lime. - *Sandstone: *Intact rock/sediments, principally formed of components with grain size between 0.2 and 2 mm. - *Conglomerates, Breccias: *Intact rock/sediments, principally formed of components with grain size larger than 8 mm. While breccias have angular components, those of conglomerates are of a rounded shape (e.g. Nagelfluh). - *Clay rocks, clay shales: *Intact rock/sediments, principally composed of clay-rich components with grain size less than 0.125 mm. - *Limestones: *Intact rocks/sediments, whose components are principally composed of calcium carbonate. - *Dolomites: *Intact rock/sediments, whose components are mostly composed of magnesium carbonate. - *Radiolarites: *Intact rock/sediments, principally formed of radiolarians (tiny animal fossils with silicate skeletons), sometimes contain lime. - *Evaporites: *Intact rock/chemical sediments which form through the evaporation of sea water (e.g. salt and gypsum) - *Carbonate evaporites: *Intact rock/sediments (cellular porous dolomites and limes) whose pore spaces are formed by a recent washing out of soluble materials. - *Granites, Syenites: *Magmatic rocks (plutonite) – light, coarse crystalline rocks composed of quartz, potassium feldspar and mica. - *Porphyrite, Quartzite porphyries: *Magmatic rocks (volcanite), which contain a fine-grained, sometimes glassy, matrix with scattered quartz or feldspar crystals. - *Volcanite: *Magmatic rocks which solidify on the Earth's surface (volcanic rocks, eruptive rocks) - *Phyllite limestone, marly shales: *Intact rocks, principally composed of clay-rich or lime-rich and sometimes mica-rich components. - *Dolomite marble, lime marble: *Metamorphic rocks which are formed from lime and dolomite recrystallised through the effects of temperature and pressure. - *Quartzite: *Metamorphic rocks, corresponding to metamorphic rocks rich in quartz (Quartz sandstone, radiolarite, etc.). - *Quartz phyllite: *Metamorphic rocks, thinly foliated, fine-grained, often with shiny surfaces, principally composed of quartz and finely dispersed mica (serizite). - *Micaschists: *Metamorphic rocks which split easily in millimetre to centimetre scale plates and are principally formed of finely foliated, dispersed (e.g. mica) or needle-shaped (e.g. amphibole) minerals. - *Gneiss: *Metamorphic rocks, coarsely foliated (centimetre of decimetre scale thick plates), principally composed of feldspar, quartz and mica. - *Amphibolites: *Metamorphic rocks, dark, mostly foliated, principally composed of amphibole (e.g. hornblende). - *Basic rocks, metabasic rocks: *Generic term for basic magmatic rocks with a silica content between 45 and 52% (intermediate). Basalts and their metamorphic equivalents constitute the principal subgroup (green schists). - *Ultrabasic rocks (Ultrabasites): *Metamorphic rocks with a low silica content (less than 45%) and less than 10% light components. Pyroxenite and peridotite as well as serpentinite and soapstone are found in this group. ## Sources - Schweizerische Geotechnische Kommission (1964–1967): Geotechnische Karte der Schweiz ## Data sources - swisstopo, Landesgeologie (2010): [GeoKarten500, GeoCover](http://www.swisstopo.admin.ch/internet/swisstopo/de/home/swisstopo/org/geology.html) ## Data owners - [Swiss Federal Office of Topography (swisstopo)](http://www.swisstopo.admin.ch/) ## Citation The terms of use ask to name the Atlas of Switzerland and the data owners, and to keep the source references in exports, screenshots and embeds. Cite the map as: > Atlas of Switzerland (2019): Lithology: type of rocks. ETH Zürich. Map data © swisstopo. https://atlasderschweiz.ch/en/theme/lithology-type-of-rocks/ ## Variants The map has 2 variants. Levels: spatial unit → time. The `u` value of a variant selects it in the links below. - Overview - 2010: `u=AAEAxQAA` (default) - Detail - 2010: `u=AAEAxgAA` ## Links Replace `{u}` with the `u` value of a variant above, or leave out `u={u}` for the default variant. The map opens at its full extent; a link cannot set the map position. - Map: https://atlasderschweiz.ch/en/theme/lithology-type-of-rocks/?u={u} - Short link, stays valid when the title changes: https://atlasderschweiz.ch/en/t/165/?u={u} - Side by side with another map: https://atlasderschweiz.ch/en/comparison/?lt=165&lu={u}&rt={id of the other map}&ru={u of the other map, or leave out} Embed in another website (allowed by the terms of use, as long as the source references stay visible): ```html ``` In the embed URL, `dm` sets what is shown: `e` the map with its title bar (default), `p` also the values of an object clicked on the map, `m` only the map with a button that opens it in the atlas. `ig=1` (default) lets the map react to scrolling and dragging only after a click into it, `ig=0` right away. The size can be changed in `style`. ## Maps to compare with - [Deposits of industrial minerals and other useful rocks](https://atlasderschweiz.ch/en/theme/deposits-of-industrial-minerals-and-other-useful-rocks.md) (id 142) - [Mineral energy raw materials](https://atlasderschweiz.ch/en/theme/mineral-energy-raw-materials.md) (id 141) - [Extraction of clayey rocks](https://atlasderschweiz.ch/en/theme/extraction-of-clayey-rocks.md) (id 193) - [Rock with karstic properties near to the surface](https://atlasderschweiz.ch/en/theme/rock-with-karstic-properties-near-to-the-surface.md) (id 106) - [Deposits of minerals and ores](https://atlasderschweiz.ch/en/theme/deposits-of-minerals-and-ores.md) (id 140) - [Quarries: extraction of stones](https://atlasderschweiz.ch/en/theme/quarries-extraction-of-stones.md) (id 191) For the use and citation of maps and data, see the [terms of use](https://atlasderschweiz.ch/en/terms-of-use/).