Carbonater

Question 1

Hvilke to typer carbonat-sten findes?

Answer 1

Limestone: CaCO3 reacts with Hal
– calcite or aragonite

Dolomite: CaMG(CO3)2 doesn’t react with HCl at low T

Mixed carbonate-siliciclastic rocks (3 types)

Question 2

Hvad kaldes de 3 typer af mixed carbonate-siliciclastic rocks?

Answer 2

Rudite: Conglomerate (calcirudite)

Arenite: Sandy calcarenite

Pelite: Marl (calcipelite)

Question 3

Hvad består carbonate rocks af?

Answer 3

Components (allochemes) +/- matrix + cement

Matrix = micrite
Cement = sparit (calcite crystals)

Main allochemes:
- Bioclasts (skeletal material)
- Ooids
- Peloids
- Intraclasts

Question 4

Hvad er sparit?

Answer 4

Carbonate cement.

Looks like grey glass; kinda transparent.
The only type of cement that you can see with the naked eye.

Question 5

Hvad er crinoider?

Answer 5

Søliljer

Question 6

Hvad er bivalves?

Answer 6

Muslinger

Asymmetriske pr. låg - men de to låg er symmetriske!

Question 7

Hvad er brachiopoder?

Answer 7

Enkelt låg er symmetrisk, men de to låg er asymmetriske

Question 8

Hvad er gasteropoder?

Answer 8

Snegle

Question 9

Hvad er ooider?

Answer 9

Små, kugleformede, “overtrukne” sedimentære korn.

Dannes normalt på havbunden, mest almindeligt i lavvandede tropiske hav.

Question 10

Hvad er Dunham classification (texture)?

Answer 10

Et skema til at definere typen af sten baseret på tekstur.

Question 11

Hvad er biogen silica?

Answer 11

Main components ? SiO2

Diatoms –> diatomite (light, white)

Sponge spicules –> spiculite (rare)

Radiolaria –> radiolarite (like micrite, don’t fizz)

Chert, flint (diagenetic) –> conchoidal fracture

Question 12

Hvordan klassificeres kul (%C)?

Answer 12

Organisk terrestrisk materiale (planter)
Tørv (50% C) –> brunkul (70% C) –> stenkul (85% C) –> antracit (95% C)

Peat -> lignite -> bituminous coal -> anthracite coal

Flydende: petroleums-olie

Question 13

I hvilken rækkefølge dannes mineraler ved fordampning af vand?

Answer 13

Calcit (CaCO3)
Gips (CaSO4)
Halit (NaCl)
K- og Mg-salte

Question 14

Hvordan klassificeres pyroklastiske sten? (tephra)

Answer 14

Consolidated = pyroclasts
Unconsolidated = tephra

> 64 mm = block, bomb = pyroclastic breccia

2-64 mm = lapillus = lapillituff

< 2 mm = coarse ash = coarse-grained tuff

< 1/16 mm = fine ash ? fine-grained tuff

Question 15

Hvordan klassificeres ore stones?

Answer 15

Ore content > 15% (mainly iron)
Very dense
Colour: red, yellow, green

BIF = Precambrian Banded Iron Formation

Phanerozoic steel-rich stone
- Oolithic ironstone
- Bioclastic ironstone
- Glauconitic sandstone

Question 16

Hvordan klassificeres fosfater?

Answer 16

P2O5-content between 5–37%

Relatively rare

Color: beige, brownish, dark grey

Sticks to the tongue

Phosphatic pebble
Phosphatic crust
Phosphatic bonebed
Bioklastic phosphorite
Phosphate-rich claystone
Phosphate-rich sandstone