Sedimentary rocks

1. Sedimentary rocks 97,3% of Hungary is covered with some kind of sediment 75% of land surface on the earth is covered by thin veneer of sediments or sedimentary rocks. Classification Based on the processes responsible for their formation, sedimentary rocks can be subdivided into three groups:  clastic sedimentary rocks biochemical (or biogenic) sedimentary rocks chemical sedimentary rocks 

2. Sedimentary rocks Rock forming minerals of sedimentary rocks: • Quartz • Feldspars (orthoclase, plagioclase) • Micas (biotite, mouscovite) • Calcite • Dolomite • Clayminerals (illite, kaolinite, montmorillonite) • …

3. Sedimentaryrocks Clastic sedimentary rocks are composed of silicate minerals and rock fragments that were transported by moving fluids and were deposited when these fluids came to rest.  

4. Sedimentaryrocks Clastic sediment, and thus clastic sedimentary rocks, are subdivided according to the dominant particle size (diameter) and cementation Not cemented sediments Gravel (>2 mm) Sand(2 – 0,06 mm) Mud/silt (0,06 - 0,002 mm) Clay (<0,002 mm) (they have cemented versions too)

5. Sedimentaryrocks Water uptake of the clay depend on the clay mineral composition Water uptake → swelling Montmorillonite up to 300 % volumetric swelling

6. Sedimentaryrocks Breccias are coarse grained rocks dominantly composed of gravel sized particles that are typically held together by a finer grained martix.The gravel sized particles are angular. Texture: cemented Minerals: quartz, feldspars, micas Usage: Load bearing structure (cut, carved, polished) – high strength, long lasting Floors, facades (slabstones) - high strength, long lasting, easy to cut, resistant to abrasion, aesthetic

8. Sedimentaryrocks ConglomeratesThe gravel sized particles that make up conglomerates are well rounded Properties same as breccias.

10. Sedimentaryrocks Sandstone(2 - 0,063 mm) Sandstones are medium grained rocks composed of rounded or angular fragments of sand size, that often but not always have a cement uniting them together. Texture: cemented Minerals: quartz, feldspars, micas Usage: Retaining wall, fence, footing - easy to cut, aesthetic Decoration (sculpture, ornament) - easy to cut, aesth. Load bearing structures (cut, carved) – high strength, long lasting Building stone (cleaved, sawed blocks) – easy to cut

15. Sedimentaryrocks SiltstoneAs its name implies, it is primarily composed (greater than 2/3) of silt sized particles, defined as grains 2–62 µm Texture: cemented Minerals: quartz, feldspars, micas Usage:radioactive waste disposal (host rock) - watertight

16. Sedimentaryrocks Claystonecomposed primarily of clay-sized particles (less than 1/256 millimeter in diameter). Texture: cemented Minerals: clay minerals (illite, kaolinite, montmorillonite) Usage:brick and cement production – chemical propertiesradioactive waste disposal (host rock) - watertight

17. Sedimentaryrocks Loesspredominantly silt-sized sediment, which is formed by the accumulation of wind-blown dust. Typically yellow. Slump is a tipical problem: volume loss due to saturation.

19. Sedimentaryrocks Biochemical rock Saturation of the solution -  precipitate - Compaction – Cementation LimestoneCaCO3 (HCl solve it - fizz) Coarselimestone Dense Limestone Freshwater Limestone

20. Sedimentaryrocks Coarselimestone Seawater origin, yellowish white, soft, high porosity (over 20%), high water intake; reaction with hydrochloric acid Texture: carbonate Minerals: calcite (CaCO3) Usage:retaining wall, fence, footing – easy to cut, carve; aestheticdecoration (sculpture, ornament) - easy to cut, carve; aesthetic

22. Sedimentaryrocks Dense limestone Seawater origin, various colours (white, red, black, brown), calcite veins, fossils; reaction with hydrochloric acid Texture: carbonate Minerals: calcite (CaCO3) Usage:floors, facades (slabstones) – high strength, resistant to abrasion, long lasting, aesthetics (but loses shine outdoors)roads, railways (crushed rock) – solid, resistant to impact, abrasion and freezingcement production

24. Sedimentaryrocks Freshwaterlimestone/travertini Freshwaterorigin,brownishyellow, pores of differentsizes; reaction with hydrochloric acid Texture: carbonate Minerals: calcite (CaCO3) Usage:floors, facades (slabstones) – highstrength, resistanttoabrasion, longlasting, aestheticsloadbearingstructures (walls, coloumns) – highstrength, longlastingdecoration (sculptures, ornaments) – easytocut, carve, aesthetic

26. Sedimentaryrocks Dolostone or dolomite rock is a sedimentary carbonate rock that contains a high percentage of themineral dolomite.CaMg(C03)2 Can either contain bedded layers or be unbedded. It is less soluble than limestone in weakly acidic groundwater, but it can still develop solution features over time. Dolostone can act as an oil and natural gas reservoir. Usuallyfractured, hardtoprocess (difficulttoformbricks), it is brittle. Usedasbulkmaterial: ballastunderroad, rail ; concreteagregate White inthevicinity of naturalfractures (Mg)

28. Sedimentaryrocks Other Sedimentary rocks Marl or marlstone is a calcium carbonate or lime-rich mud or mudstone which contains variable amounts of clays and silt. The dominant carbonate mineral in most marls is calcite, but other carbonate minerals such as aragonite, dolomite, and siderite may be present. his finely bedded material Usage.: cement industry, non-load bearing structures, typicaly highly fractured, it can be only used as bulk material. Bauxite, an aluminium ore, is the world's main source of aluminium. Red, pink, water uptake can be high Usage: in paints, aluminium production, sandpaper. Coal, lignite, anthracite…