PERMEABILITY OF COASTAL SANDS: INDEPENDENT MEASUREMENTS AND VALIDATION OF PREDICTIVE RELATIONSHIPS

Permeability, the ability of a fluid to pass through a porous medium, is a property of the utmost importance in the exchange of matter and energy within sediments and between sediments and the overlying water column where physical forcing is present. Permeability itself is infrequently measured but rather estimated from empirical relationships (for example, Krumbein and Monk or Kozeny-Carman) based on other sedimentary characteristics, such as grain-size distribution statistics and porosity. The purpose of this study is to evaluate permeability measurements with permeability estimates using these relationships on coastal sands of two different types: predominantly carbonate sands from O`ahu, Hawaii, and predominantly clastic/silicate sands from Long Bay, South Carolina. Grain size statistics are obtained using wet sieving, which is contrasted in a selected subset of samples with dry sieving after oxidation of organic matter and disaggregation. Porosity is determined by thermogravimetry, while permeability is measured using the constant-head method. Our findings provide much needed data to inform the discussion on the validity of these long-used predictive relationships when applied to coastal sands.