8: Diagenesis
- Page ID
- 20385
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Diagenesis is the transformation from sediment into sedimentary rock. It includes everything that is post-depositional but pre-metamorphic. Its an important time in the history of the rock because of the potential for compaction, textural changes, movement of fluids through pore spaces, as well as the creation, migration, and ultimate fate of fossil fuels.
- Explain the most important diagenetic processes
- Identify diagenetic textures and structures and explain their origin.
Chapter thumbnail shows a stylolite cross-cutting an ooid in the Cambrian Meagher Formation, SW Montana (Michael C. Rygel via Wikimedia Commons; CC BY-SA 4.0).
- 8.1: Diagenetic Processes
- Compaction is a reduction in volume caused by burial; the amount of compaction depends on the properties of the sediment as well as local/regional processes. Compaction occurs via dewatering, grain-scale deformation, and dissolution. Cementation is the precipitation of mineral cements from fluids. Other processes such as replacement and/or dissolution can be important in some rocks.
- 8.2: Diagenetic Structures
- A variety of distinctive structures form in association with diagenesis. Beyond being potentially visually striking features, these structures record processes such as the precipitation of minerals, dissolution, surface processes, and bioturbation.