Features of Coarse-Grained, High-Concentration Fluids and Their Deposits

Abstract

ABSTRACT Field, laboratory, and theoretical investigations of fluids with very high concentrations of solid particles in water (up to 90%) show that they exhibit the property of strength, have high apparent viscosities which vary with velocity, have high bulk densities, and flow in laminar fashion or with greatly reduced turbulence. Debris flows, observed during movement and emplacement, deposit debris which is poorly sorted, has an unsupported framework, may contain elongate fragments which are roughly aligned parallel to bedding, and may show inverse grading. On low slopes, debris flow deposits commonly overlie easily eroded materials with little or no features of erosion. Subaqueous deposits in the geologic record which show these or somewhat similar features were probably emplaced as highl concentrated dispersions.