Drilling Logs Of Government Core Drills

This report documents results of a program to evaluate effectiveness of more or less conventional subsurface samplers in obtaining representative and undisturbed samples of noncohesive alluvial materials containing large quantities of gravels and cobbles. This is the first phase of a research program to improve core drill methods. Samplers evaluated consisted of the Lawrence Livermore Laboratory membrane sampler, 4-in. Denison sampler, 6-in. Denison sampler, 5-in. Modified Denison sampler, and 3-in. thinwall drive tube. Small representative samples were obtained with the Denison samplers; no undisturbed samples were obtained. The field work was accomplished in the Rhodes Canyon area, White Sands Missile Range, New Mexico.