Interpretation of elongated SP anomalies is usually accomplished by assigning two‐dimensional (2-D) shapes such as inclined sheets and horizontal cylinders to the source. However, since the shapes of the profiles are similar, it is extremely difficult to distinguish the source as cylindrical or sheet‐like from a given field profile. By defining two characteristic ratios from anomalies between the two extrema on the profile, we present a nomogram which not only helps identify the shape of the 2-D anomaly source, but also facilitates estimating all the parameters. Using this nomogram a field profile can be interpreted in a very short time with ease and accuracy. The method is demonstrated on two examples. Error response of the parameters estimated due to errors in data was studied through imposing ±5 percent to ±25 percent errors in the two characteristic ratios in two synthetic profiles due to a cylinder and a sheet. While the results on the cylinder showed negligible errors, the percent errors for the sheet model, in general, are less than the percent errors imposed.

In the analysis and interpretation of sP anomalies, two-dimensional finite sheet models are equated to the double line of poles. The profiles over such a model being asymmetric with a minor positive peak and a major negative peak, a double logarithmic curve matching technique simpler than that of Meiser is suggested in the paper for easy and unique solution for all values of depth, dip and length. This technique along with a few others have been tested on two profiles across the sulphide deposit from the Rakha Mines, Singhbhum copper belt, India.