Topic 8 - Sedimentary Rock

What do sedimentary deposits contain in high-energy environments?

Gravel and sand

What is the composition of rock gypsum?

Gypsum

What is the composition of rock salt?

Halite

What is the texture of coal?

Massive, blocky

What is porosity?

Measure of amount of empty space contained in a rock

What is the texture of chert?

Microcrystalline

What is the texture of travertine?

Microcrystalline

What is the composition of chert?

Microcrystalline silica

What are evaporites?

Minerals formed when evaporation leads to inorganic precipitation of dissolved compounds A form of chemical sediment

What is clay?

Most abundant and finest grained sediment particle, created by decomposition of silicate rocks, usually during hydrolysis Composed of fine-grained minerals

What is the texture of shale?

Mud, laminated

What is the texture of claystone?

Mud, massive

What do sedimentary deposits contain in low-energy environments?

No gravel, little sand, dominated by mud

What is sedimentary rock?

Rock formed by organic or inorganic precipitation or by deposition and cementation of sediment

What is the texture of conglomerate?

Rounded gravel

What is rounding?

Rounding off of sharp edges or corners of grains

What is the texture of arkose?

Sand

What is the texture of lithic sandstone?

Sand

What is the texture of quartz sandstone?

Sand

What do sedimentary deposits contain in moderate-energy environments?

Sand and mud

What is the texture of coquina?

Sand or gravel

What does gravity drive in the rock cycle?

Sediment erosion and transportation from mountains to sedimentary basins

What are environments of deposition?

Sedimentary basins where sediment is deposited

What are chemical sediments?

Sediments produced by inorganic precipitation of dissolved compounds

What are biogenic sediments?

Sediments produced by organic precipitation of compounds or consisting of remaind of living organisms

What is sorting?

Separation of grains by density and size

What is the composition of coquina?

Shell fragments

What is the texture of skeletal limestone?

Visible or microscopic skeletal fragments

How does evaporation result in the formation of chemical sediments?

Water molecules changes from liquid to gas, but dissolved compounds are left behind

What does solar energy drive in the rock cycle?

Weathering

When does the crystallization of chemical sediments occur?

When ions develop covalent and ionic bonds to form chemical compounds that produce solid minerals

Are organic sediments most likely to originate within or outside of sedimentary basins?

Within sedimentary basins

What is sand?

Rock and mineral particles 0.0625 mm to 2 mm in diameter

What are the 4 major biogenic sedimentary rocks?

1) Chalk 2) Coal 3) Coquina 4) Skeletal limestone

What are the 5 major types of chemical sedimentary rocks?

1) Chert 2) Dolostone 3) Rock gypsum 4) Rock salt 5) Travertine

What are the 3 types of sediment?

1) Clastic sediment 2) Chemical sediment 3) Biogenic sediment

What are the 8 major types of clastic sedimentary rock?

1) Conglomerate 2) Breccia 3) Quartz sandstone 4) Arkose 5) Lithic sandstone 6) Siltstone 7) Claystone 8) Shale

What is 2 things affect the sediment deposit of an environment?

1) Environmental energy 2) Sediment availability

What are the 2 ways in which lithification takes place?

1) Cementation 2) Compaction

What 2 processes result in the evolution of the composition of sedimentary deposits over time?

1) Grains are subjected to continuous chemical weathering as they are transported, which tends to removed unstable grains and increase relative abundance of more stable grains 2) New types of sediments are introduced, such as biogenic sediment, local weathering products, and locally precipitated chemical sediments

What is the size of clay, gravel, sand, and silt from largest to smallest?

1) Gravel 2) Sand 3) Silt 4) Clay

What 2 factors cause the cementation and compaction of sediments into sedimentary rock?

1) High temperatures 2) High pressure

What 3 things power the rock cycle?

1) Solar energy 2) Geothermal energy 3) Gravity

What are 2 processes that grains of sediment undergo as they are transported?

1) Sorting 2) Abrasion

What are the steps in the rock cycle?

1) Tectonic uplift 2) Weathering 3) Erosion and transportation 4) Deposition 5) Burial 6) Lithification

What are the steps in the formation of sedimentary rock?

1) Weathered particles of sediment are eroded from land through action of gravity, wind, and running water 2) Rock and mineral grains are washed downstream, where they eventually come to rest on bottoms of rivers, lakes, and oceans 3) Over time they accumulate as layer upon layer of eroded sediments 4) As they are buried, overlying pressure builds and those layers consolidate and compact 5) Grains are cemented by dissolved compounds in groundwater and become solid sedimentary rock

What is a well-sorted deposit?

A deposit in which grains are nearly all same size

What is a poorly sorted deposit?

A deposit in which grains vary widely in size

What is the difference in distance travelled of a well-rounded grain and an angular grain?

A well-rounded grain has probably travelled a great distance from its original source An angular grain has not travelled far from its source

What is the texture of breccia?

Angular gravel

What are clastic sediments?

Broken pieces of crust deposited by water, wind, ice, or some other physical process

What is the composition of skeletal limestone?

Calcite

What is the composition of travertine?

Calcite from saturated fluids

What is the composition of breccia?

Clastic, lithic fragments

What is the composition of conglomerate?

Clastic, lithic fragments

What is the texture of chalk?

Clay or mud

What is iron oxide

Compound composed of oxidized iron

What is the composition of coal?

Concentrated carbon

What is the texture of dolostone?

Crystalline

What is the texture of rock gypsum?

Crystalline

What is the texture of rock salt?

Crystalline

Are most chemical sediments deposited near the locations where they form or are they transported from afar?

Deposited near locations where they form

What is lithology?

Description of a rock's composition and texture

What is the composition of dolostone?

Dolomite

Why does water have a tendency to sort particles according to their mass?

Energy of moving water waxes and wanes, so grains of equal mass tend to erode together and be deposited together

What is mud?

Unconsolidated, water-saturated sediment of silt and clay grains

What is silt?

Particle between 0.002 mm and 0.063 mm

What is cementation?

Particles are bound together by natural cements that are inorganically precipitated from dissolved compounds in groundwater

What is compaction?

Particles are compacted and consolidated by pressure from weight of overlying layers of sediment

What is sediment?

Particles of mineral, broken rock, and organic debris that are unconsolidated Formed by weathering

What does geothermal energy drive in the rock cycle?

Plate motion

What is abrasion?

Process in which solid rock is worn away by impact Grains become smaller and more spherical the longer they are transported

What is lithification?

Process that converts sediment into sedimentary rock

What is the composition of quartz sandstone?

Quartz

What is the composition of arkose?

Quartz, feldspar

What is the composition of lithic sandstone?

Quartz, feldspar, lithic fragments

What is a source area?

Region where crust weathers and erodes to produce sediment

What is environmental energy?

Relative strength of natural processes

What is the composition of siltstone?

Silicate minerals

What minerals make up the majority of clastic sediments?

Silicate minerals

What is the composition of claystone?

Silicate minerals and clay minerals

What is the composition of shale?

Silicate minerals and clay minerals

What is the texture of siltstone?

Silt, massive

What is the composition of chalk?

Skeletal coccolithophorids

Do sediment deposits tend to become smaller grained and better sorted or larger grained and poorer sorted with greater distance from their source area?

Small grained and better sorted

Why are unstable mafic minerals usually not important constituents of most clastic sediments?

They are vulnerable to chemical deterioration and do not readily survive weathering process