Diagenesis and Cement Types

Flashcards covering key vocabulary related to diagenesis, cement types, and their characteristics.

Diagenesis

Post-depositional physical, chemical, and biological changes in sediments.

Marine Diagenesis

Diagenesis in a marine setting, typically shallow subtidal to intertidal, influenced by seawater.

Meteoric Diagenesis

Diagenesis under freshwater, typically subaerial exposure, low Mg levels.

Burial Diagenesis

Deep subsurface processes under increased pressure, temperature, and compaction.

Vadose Zone

Above the water table; pore spaces are partially air-filled.

Phreatic Zone

Below the water table; pore spaces saturated with water.

Saturation

A fluid is saturated when it holds the maximum amount of dissolved ions.

Supersaturation

Condition leading to precipitation of solids from a fluid.

Cementation

Process where minerals precipitate in pore spaces to bind sediments together.

Fibrous Cement

Cement with long, needle-like crystals growing perpendicular to substrate.

Bladed / Prismatic Cement

Cement with elongated, blade-shaped crystals.

Equant / Drusy Cement

Interlocking equidimensional crystals filling pores, increasing in size continously.

Syntaxial Overgrowth

Cement that develops continuity with the base grain.

Strontium (Sr)

Element that follows aragonite and high Mg-calcite; high in marine cements.

Iron (Fe)

Element associated with reducing conditions and burial processes.

Manganese (Mn)

Element that substitutes for calcium in calcite under reducing conditions.

Vadose Cements

Often unsaturated, with irregular distribution; forms in air-filled pores.

Phreatic Cements

Saturated, with slow-moving pore water and specific cement morphologies.