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<br />19 <br />Core Samples <br />Core samples were obtained with a hand driven sampling tube con- <br />taining metal cylinders, 2.7 cm in diameter and 3.0 cm in length. <br />Relatively undisturbed core samples of topsail were easy to obtain <br />using this method but core samples of the underlying spoils were more <br />difficult. Frequently spoils consist of coarse shale or sandstone <br />fragments, each still highly consolidated, and the hand driven sampling <br />tube cannot penetrate individual rocks very effectively. The ease with <br />which core samples of the spoils could be obtained, if they could be <br />obtained at all, varied greatly from site to site. <br />Laboratory Measurements <br />Saturated Hydraulic Conductivity <br />• The core samples of topsoil and spoils were prepared by covering <br />one end of each core with cheesecloth and fastening the cloth with a <br />rubber band. The cores were soaked, cloth covered ends down, for 24 <br />hours in a tray filled with water to the top of the cores. The prepared <br />"~ samples were then quickly transferred to a constant head pen^eameter <br />J similar to the one described by Klute (1965). Discharge through the <br />J core samples was carefully measured for selected time intervals for a <br />twenty minute period while the constant head of water was maintained at <br />J a level 2.7 cm above the top of the sample. Hydraulic conductivity <br />was then calculated (McWhorter and Sunada, 1977, p. 79): <br />K = -~- <br />~hA <br />