The four main types of sedimentary rocks,

-Clastic: (ex. arkose –type of sandstone) cemented together sediments and rock fragments

-Biochemical: (ex. Limestone) made from the shells of organisms

-Organic (ex. Coal) : carbon-rich relicts of plants

Chemical: minerals that precipitate from water

Examples of the four main types of sedimentary rocks

-Clastic – arkose

-Biochemical – limestone

-Organic – coal

-Chemical - travertine

how each type of sedimentary rock is formed 

-Clastic: (ex. arkose –type of sandstone) cemented together sediments and rock fragments

1) Weathering – processes that breakdown rocks (physical or chemical)

2) Erosion – removal of rock chunks from substrate

3) Transport – moving sediments away from the source (à water, wind, ice)

4) Deposited – sediment falls out of the transport mechanism

5) Lithification – cementation of sediments to form a rock

Compaction: burial causes water and air to be squeezed from the pore space

Cementation:  minerals precipitate from groundwater to fill in the pore spaces– cement each grain together

-Biochemical: (ex. Limestone) made from the shells of organisms

1.Animals make shells

2.Shells sink

3.Burial & Cementation

-Organic (ex. Coal) : carbon-rich relicts of plants

1.Plants die

2.Compaction and decay in stagnant, oxygen-poor water

3.Deep burial

Chemical: minerals that precipitate from water

1.Salty Water

2.Evaporation

3.Precipitates

The five steps to forming a clastic sedimentary rock.  

-Clastic: (ex. arkose –type of sandstone) cemented together sediments and rock fragments

1) Weathering – processes that breakdown rocks (physical or chemical)

2) Erosion – removal of rock chunks from substrate

3) Transport – moving sediments away from the source (à water, wind, ice)

4) Deposited – sediment falls out of the transport mechanism

5) Lithification – cementation of sediments to form a rock

Chemical weathering

How chemical and physical weathering can act together.  

-When physical weathering increases the surface area (breaks something up) chemical weathering (water) can seep through the cracks

-An intact rock with feldspar turns into clay, the clay then washes away

-Differential weathering – uneven weathering of material

            (ex. Peanut m and m ---- chocolate, shell, then peanut)

-Minerals that form at the highest temperatures and pressures are least stable and will weather first.

Which minerals would weather first and which would weather last.  

-Granite

            -Quartz (weathers last, like peanut) – most stable

            -Feldspar (Weathers next, like shell)

            -Amphibole (weather first, like the chocolate) – least stable

-mafic minerals crystallize first at high temperatures, followed by felsic which crystallize last at low temperatures

The difference between weathering and erosion.  

Weathering – breaks down the rock

Erosion  - moves away the pieces (swallowing m&m)

The three main sediment transport mechanisms.   

-Wind - can generally only transport small size particles (sand)

-Glaciers -can transport all size

-Water- depends on strength of water

How sediments change/evolve as they travel further from the source.  

-Grains get smaller

-Grains get rounder

-Grain sorting improves

How sediments change/evolve as they travel further from the source. 

-Size 

Boulderàcobbleàpebbleàsandàsiltàclay

How sediments change/evolve as they travel further from the source. 

-Roundness 

AngularàSubangularàSubroundedàRounded 

How sediments change/evolve as they travel further from the source. 

-Sorting

-In poorly sorted sediment -great variety of different clast sizes

-In well-sorted sediment -all the clasts are the same size[image]

The types clastic rocks you would expect to see near the source verses those you would expect to see far from the source.  

Rounded pebbles and cobbles, angular clasts etc… à sand-sized grainsà silt-sized clastsàclay and/or very fine silt

Breccia (angular)/Conglomerate (rounded) à SandstoneàSiltstoneàShale (platy)/Mudstone

Distance from sourceà

What processes have helped to shape Bryce Canyon. 

•Some parts are eroded more than others

•Bands of red and bands of white (layering)

•Fine grain sediments[image][image][image]

layering or stratification in sedimentary rocks

coarse sedimentary rock consisting of angular fragments; or rock broken into angular fragments by faulting

- minerals precipitate from groundwater to fill in the pore spaces– cement each grain together

– naturally formed cracks in rocks

– sedimentary rock formed by calcite

coarse-grained sedimentary rock consisting almost entirely of quartz

– an accumulation of loose mineral grains, such as boulders, pebbles, sand, silt, or mud that are not cemented together

rock that forms either by the cementing together of fragments broken off preexisting rock or by the precipitation of mineral crystals out of water solutions at or near the Earth’s surface

fine-grained sedimentary rock generally composed of very small quartz grains

(1) the range of clast sizes in a collection of sediment; (2) the degree to which sediment has been separated by flowing currents into different-size fractions

a recognizable layer of a specific sedimentary rock type or set of rock types, deposited during a certain time interval, that can be traced over a broad region

the vertical sinking of the Earth’s surface in a region, relative to a reference plane

a sloping apron of fallen rock along the base of a cliff