On the settling of marine carbonate grains: Review and challenges

Particle settling velocity is a fundamental parameter in sedimentology and engineering, has accordingly received much attention the literature. Grain properties, such as shape drag coefficient, which affect terminal velocity, also control threshold of initiation motion sediment entrainment into suspension. Terminal therefore provides insights dynamics modern past depositional environments important for marine engineering works. Despite global importance resedimented carbonates study particle hydrodynamics strongly biased towards terrigenous sediments. This paper presents review carbonate grains associated shape, grain size density. For these parameters are more complex than siliciclastic counterparts due to their common biogenic origin, introducing wide range morphologies, densities abrasion products result skeletal nature grains. includes an extensive database published composition-specific velocities, well constituents. The corals, coralline red algae, bivalves, brachiopods, gastropods, Halimeda green bryozoans, crinoids, echinoderms, Alcyonarian spicules, numerous benthic planktic foraminifers, fecal pellets. density function structure mineralogy exerts another on with unclarity definitions hampering effective communication variation single-grain hydrodynamic behaviour implies careful application previously proposed equations prediction bulk sand. firm basis there need additional systematic investigations enable adequate broad spectrum forms densities. Emerging technologies automated velocimetry, computational fluid dynamics, machine learning microtomography provide exciting avenues future understanding particles complexity natural