sedimentatagrain

Sedimentatagrain is a term sometimes encountered in discussions of sedimentology to denote a grain whose preserved features primarily reflect the original sedimentation process. The word blends “sedimentation” and “grain” and is used to emphasize a grain that carries information about depositional conditions.

Formation and characteristics: Sedimentatagrains are typically detrital or biogenic grains that were deposited from a suspension in air or water and afterward fortuitously preserved with minimal post-depositional modification. Their grain size, roundness, mineralogy, and surface textures record transport energy, source-area lithology, and depositional setting (fluvial, deltaic, aeolian, or marine). They may retain thin weathering rims or coatings that snapshot surface processes prior to burial.

Distinction and significance: The concept contrasts with authigenic grains that form by diagenetic mineral precipitation after burial. Identifying sedimentatagrains helps reconstruct provenance and paleoenvironments, especially when combined with grain-size distributions and petrographic provenance analyses.

Analytical approaches and limitations: Analysts use optical microscopy, scanning electron microscopy with energy-dispersive spectroscopy, and cathodoluminescence to characterize grain morphology and composition. Dating methods such as luminescence dating may constrain deposition timing for sediments where sedimentatagrains are well preserved. However, the term is not universally used, and many researchers prefer standard descriptors like detrital grain or mineral grain in provenance studies.

See also: Sedimentology, Detrital grain, Diagenesis, Provenance, Sedimentary rock.