International Geological Journal - Official Journal of the Carpathian-Balkan Geological Association

Shaping of clay fragments during transport: a theoretical model

Published: Oct 2005

Pages: 455 - 460


Abstract: Irregular blocks of cohesive clay (IBC) are transformed into spherical clay balls (SCB) during transport across a sedimentary basin bed by runoff. This transformation is controlled by rotation of the IBC about a randomly changing axis. During this process, deformation dominates; abrasion is less significant. Based on a theoretical model, the equation describing SCB formation, Ψ = 1-(1-Ψ0)exp(kλ/πdef), was derived in terms of the SCB instantaneous sphericity, Ψ, the IBC initial sphericity, Ψ0, the transport length, λ, and the effective diameter, def. Based on the proposed model, the length of transport can be estimated if sphericity and effective diameter are known. Despite the verification in the artificial setting, the presented model is valid also for the natural environment of various clay rich cliffs or scarps.

Keywords: Czech Republic, Rudice Formation, modelling, recent process, sedimentology, basin bed, clay ball

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