Ear212 - Carbonate Diagenesis

Front 1

Name three different environments in which carbonate diagenesis occurs

Back 1

Near surface marine.
Meteoric environments.
Deep burial environments.

Front 2

Describe the process of cementation.

Back 2

Mineral growth in voids, between grains or in cavities.

Front 3

Describe neomorphism.

Back 3

Replacement and recrystallization of minerals.

Front 4

Describe micritisation.

Back 4

Alteration of grains on or below the seafloor.
Grains in a carbonate sediment (allochems) are transformed into fine-grained calcite from their original form usually removing their internal structure.

Front 5

Describe carbonate compaction.

Back 5

Compaction of sediments is driven towards lower porosities and higher densities as a function of increasing stress and chemical reactions.

Front 6

Describe dissolution.

Back 6

Undersaturated pore fluids, dissolve carbonates.

Front 7

Describe dolomitization.

Back 7

Process of transforming limestone into dolomite. When limestone comes into contact with magnesium-rich water calcite, CaCO3 is replaced with calcium and magnesium carbonate, CaMg(CO3)2 requireing large scale recrystalization.

Front 8

Name some common principal carbonate cements.

Back 8

Aragonite.

High-Mg calcite.

Low-Mg calcite.

Dolomite.

Front 9

Name some less common carbonate cements.

Back 9

Ankerite.

Siderite.

Kaolinite.

Quartz.
Gypsum.

Halite.

Anhydrite.

Front 10

What does the mineralogy and morphology of carbonate cements depend on?

Back 10

The Mg/Ca ratio and carbonate supply rate.
Low CO32 supply = slow growth for example. This is typical of meteoric and burial environments.

Front 11

What are the three main diagenetic environments?

Back 11

Marine (vadose and phreatic).
Near surface meteoric (vadose and phreatic environments).

Burial at depth.

Front 12

Name 6 different processes associated with carbonate diagenesis?

Back 12

Dissolution.

Cementation.

Micritsation.

Neomorphism.

Compaction.

Dolomitization.

Front 13

List 4 different cement morphologies associated with carbonate diagenesis?

Back 13

Isopachous.

Acicular.

Equant.

Drusy?

Front 14

Provide a fully annotated sketch of a carbonate shelf, illustrating the location of different marine and meteoric diagenetic zones (phreatic & vadose, etc).

Back 14

LEARN THIS!

Front 15

Describe and account for the diagenetic processes and products identifiable in the meteoric diagenetic zones.

Back 15

See word document

Front 16

Describe and account for the processes and products identifiable in marine diagenetic zones.

Back 16

See word document.