diagenisis

Question 1

What is diagenesis?

Answer 1

Compaction of sediments into a rock, happens before the pressure and temperature reaches metamorphism. It involves physical, chemical and biological processes that turn sediments into sedimentary rock.

Processes include compaction, recrystallization, solution (including pressure solution), cementation, authigenesis (neocrystallization), replacement (including neomorphism), and bioturbation.

Question 2

How is pressure solution working?

Answer 2

When the pressure increases, the grains will ‘melt’ together. The boundary between them gets smooched and they lock together.

Question 3

What is syntaxial overgrowth?

Answer 3

Cement will start to grow around the edge of the grains and close the pores. It is an important part of lithification.
The cement comes from dissolved silica, which wants to precipitate around a core.

Question 4

How are carbonate cement named?

Answer 4

Sparite