Simple Formulae for Estimating the Depth and Dimension of Some Geological Bodies From Gravity Anomalies

Abstract

A simple method  for determining the depth and radius of some simple geological bodies such as a sphere and a horizontal cylinder  is presented. The method utilizes all of the data points to calculate the  body parameters.  The depth is estimated  from the mean of the depths determined from various fractions of the maximum anomaly and their corresponding widths. The radii of the two bodies are  calculated from the areas under the respective gravity profiles. Additionally , the radial symmetry of the gravity anomaly due to a sphere has been utilized to calculate the excess mass from a single profile. The radius determined from the excess mass is independent of depth estimate. This method of determining the radius is more robust than the one based on calculating the area.  An error analysis showing the effects of truncation and zero-level errors on the estimated radius  is  also discussed.