Klassifikation af sedimentære sten

Question 1

Hvad består en sedimentær sten af?

Answer 1

+/- komponenter +/- matrix + cement

Fordi:
+/- komponenter +/- matrix = sediment
sediment + cement = sedimentær sten

Fx:
Sand = komponent
Mix af ler og sand = sediment
Sandsten = sediment + cement

Question 2

Hvilke 8 typer af sedimentære sten findes der?

Answer 2

Siliciclastic (terrigenous)
Carbonate
Siliceous
Coal

Evaporites
Pyroclastics
Ore stones
Phosphates

Question 3

Hvilke 2 typer af siliciklastiske sten findes der?

Answer 3

Terrigenous = derived from the erosion of rocks on land

Pyroklastisk = derived from volcanoclastic eruptions

Question 4

Hvad er grain mineralogy I en siliciclastic terrigenous sten?

Answer 4

Quartz (SiO2)
Feldspar
Lithic fragments (igneous or metamorphic)

Question 5

Hvad er pelitter?

Answer 5

Claystone (mud)
- Clay
- Very tiny grain size

Siltstone (silt)
- Very fine silt
- Fine silt
- Medium silt
- Coarse silt
- Not quite as tiny grain size

Question 6

Hvad er arenitter?

Answer 6

Sandstone (sand)
- Very fine sand
- Fine sand
- Medium sand
- Coarse sand
- Very coarse sand
- Grain size micrometers to millimeters

Question 7

Hvad er ruditter?

Answer 7

Conglomerate/breccia (gravel)
- Granule
- Pebble
- Cobble
- Boulder
- Millimeters in grain size (up to 4m of boulders)

Question 8

Hvilken procentdel matrix skal der være i hhv. sandstone og greywacke?

Answer 8

Sandstone (arenite): < 15% matrix = grain-supported

Greywacke: > 15% matrix = matrix-supported

Question 9

Hvad er de 5 stadier af grain sorting?

Answer 9

Very well sorted

Well sorted

Moderately sorted

Poorly sorted

Very poorly sorted

Question 10

Hvad er sphericity og angularity?

Answer 10

Low sphericity = aflange
High sphericity = runde

Very angular = close to the source
Well rounded = afrundede = lang transporttid

Question 11

Hvordan klassificeres ruditter?

Answer 11

Coarse siliciclastic sedimentary rock, whose main components (≥33% p.vol.) are mostly made of gravels.

Rounded gravels -> Conglomerate
Angular gravels -> Breccia

Monomict: One type of gravel
Oligomict: Few (2 – 3) types of gravel
Polymict: Numerous types of gravel

Type of matrix (matrix can be a sandstone for instance!)

Matrix-supported conglomerate: Diamictite

Question 12

Hvad er forskellen på matrix-supported og grain-supported?

Answer 12

Matrix-supported = matrixen ligger mellem korn og gør, at de ikke rører hinanden.

Grain-supported = kornene rører ved hinanden.

Question 13

Mohs Hardness Scale

Answer 13

2,5 = fingernail
3,5 = copper penny
5,5 = knife/glass
6,5 = steel nail
8,5 = masonry drill bit

1 = talc
2 = gypsum
3 = calcite
4 = fluorite
5 = apatite
6 = orthoclase
7 = quartz
8 = topaz
9 = corundum
10 = diamond