Which of the following is/are diagenetic process(es)?
Show Hint
- Dolomitization
- Flocculation
- Neomorphism
- Cementation
The Correct Option is A, C, D
Solution and Explanation
Diagenesis covers all the physical, chemical, and biological changes that happen to a sediment after it is deposited and buried, but before it turns into a metamorphic rock. It includes compaction, cementation, dissolution, recrystallization, and replacement of minerals.
Step 2: Check dolomitization.
Dolomitization is the replacement of calcite or aragonite in a limestone by the mineral dolomite, usually through magnesium-rich pore fluids moving through the rock after deposition. This replacement happens during burial, so it is a diagenetic process. Option (A) is correct.
Step 3: Check flocculation.
Flocculation is the clumping together of fine clay particles when they meet salt water, such as where a river meets the sea. This clumping controls how and where the clay settles out, so it is part of deposition itself, not a change that happens to the sediment after burial. Option (B) is incorrect.
Step 4: Check neomorphism.
Neomorphism is the change of a mineral into a new crystal of the same or a related mineral, such as fine aragonite mud recrystallizing into coarser calcite, without a change in the overall rock composition. This recrystallization happens during diagenesis. Option (C) is correct.
Step 5: Check cementation.
Cementation is the precipitation of minerals such as calcite, silica, or iron oxide in the pore spaces between grains, binding loose sediment into a solid rock. This is one of the main processes of lithification during diagenesis. Option (D) is correct.
Step 6: Final answer.
Dolomitization, neomorphism, and cementation all take place after deposition and are diagenetic processes, while flocculation happens during deposition itself.
\[ \boxed{\text{(A), (C), (D)}} \]
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