UNDERGROUND AND SURFACE GRAVITY SURVEY, LEADWOOD, MISSOURI

Abstract

A surface gravity survey consisting of 214 stations covering approximately four square miles was conducted over and adjacent to the North Leadwood Mines at Leadwood, Missouri. A corresponding survey of 278 stations was carried out in the mine workings. A method of reducing underground gravity observations is outlined. The principal factors limiting the accuracy of the underground observations are given. Methods for determining rock densities are described. A comparison of the surface and underground gravity maps shows that major Precambrian knobs were revealed by both surveys. Smaller structures not shown on the surface map were revealed by the underground survey. Anomalous density areas between the level of the two surveys were easily located.