Sedimentary rock

Sedimentary rocks are types of <a href="/facts/Rock_(geology)/FXCJkmop">rock</a> that are formed by the accumulation or deposition of <a href="/facts/Sediment/zsIH1A6U">sediments</a>, ie. <a href="/facts/Mineral/LkUFbNmv">mineral</a> or <a href="/facts/Organic_matter/t17tVCvk">organic</a> particles, at <a href="/facts/Earth/HLLmDfj0">Earth's surface</a>, followed by <a href="/facts/Cementation_(geology)/gjsJHkBv">cementation</a>. <a href="/facts/Sedimentation/qUgHGvhd">Sedimentation</a> is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called <a href="/facts/Sediment/zsIH1A6U">sediment</a>, and may be composed of <a href="/facts/Detritus_(geology)/UBsjHYRH">geological detritus</a> (minerals) or <a href="/facts/Detritus/8IjhrXA6">biological detritus</a> (organic matter). The geological detritus originated from <a href="/facts/Weathering/uSYGlv0H">weathering</a> and <a href="/facts/Erosion/gaGJXy0W">erosion</a> of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes. The geological detritus is transported to the place of deposition by water, wind, ice or <a href="/facts/Mass_wasting/CKURKaMQ">mass movement</a>, which are called agents of <a href="/facts/Denudation/VpfyfhxE">denudation</a>. Biological detritus was formed by bodies and parts (mainly shells) of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies (<a href="/facts/Marine_snow/mLM6Ea24">marine snow</a>). Sedimentation may also occur when dissolved minerals precipitate from <a href="/facts/Aqueous_solution/eRNr3MH2">water solution</a>.
The sedimentary rock cover of the continents of the <a href="/facts/Earth%27s_crust/VSy2u31r">Earth's crust</a> is extensive (73% of the Earth's current land surface), but sedimentary rock is estimated to be only 8% of the volume of the crust. Sedimentary rocks are only a thin veneer over a crust consisting mainly of <a href="/facts/Igneous_rock/xeMJhUah">igneous</a> and <a href="/facts/Metamorphic_rock/JRp6dsCm">metamorphic rocks</a>. Sedimentary rocks are deposited in layers as <a href="/facts/Stratum/w5D4VAwa">strata</a>, forming a structure called <a href="/facts/Bed_(geology)/vgEm2Y93">bedding</a>. Sedimentary rocks are often deposited in large structures called <a href="/facts/Sedimentary_basin/dVkfKMrB">sedimentary basins</a>. Sedimentary rocks have also been found on <a href="/facts/Mineralogy_of_Mars/Dh3BpGeU">Mars</a>.
The study of sedimentary rocks and rock strata provides information about the subsurface that is useful for <a href="/facts/Civil_engineering/avh5kEq2">civil engineering</a>, for example in the construction of <a href="/facts/Road/3aadH4s3">roads</a>, <a href="/facts/House/fdDCUhyD">houses</a>, <a href="/facts/Tunnel/PJNSaSIw">tunnels</a>, <a href="/facts/Canal/pBE8LsJx">canals</a> or other structures. Sedimentary rocks are also important sources of <a href="/facts/Natural_resource/w9WXxMx3">natural resources</a> including <a href="/facts/Coal/83kV3qxg">coal</a>, <a href="/facts/Fossil_fuel/BPgxAqB7">fossil fuels</a>, <a href="/facts/Drinking_water/FmSJcKGG">drinking water</a> and <a href="/facts/Ore/kgc9DssX">ores</a>.
The study of the sequence of sedimentary rock strata is the main source for an understanding of the <a href="/facts/History_of_the_Earth/0aEAQF0k">Earth's history</a>, including <a href="/facts/Palaeogeography/dzRnT27A">palaeogeography</a>, <a href="/facts/Paleoclimatology/p3x22QaC">paleoclimatology</a> and the <a href="/facts/Evolutionary_history_of_life/Ss6eB0EX">history of life</a>. The <a href="/facts/List_of_academic_disciplines/wSo6525k">scientific discipline</a> that studies the properties and origin of sedimentary rocks is called <a href="/facts/Sedimentology/X6BES3hG">sedimentology</a>. Sedimentology is part of both <a href="/facts/Geology/WGvVRIYF">geology</a> and <a href="/facts/Physical_geography/NByHKLCQ">physical geography</a> and overlaps partly with other disciplines in the <a href="/facts/Earth_science/rQsXCSbM">Earth sciences</a>, such as <a href="/facts/Pedology_(soil_study)/T7rCuFBJ">pedology</a>, <a href="/facts/Geomorphology/MDf2I2h5">geomorphology</a>, <a href="/facts/Geochemistry/05094gDu">geochemistry</a> and <a href="/facts/Structural_geology/e6tGSc6K">structural geology</a>.

Sedimentary rock open-in-new

Sedimentary rock