An enhanced trend surface analysis equation for regional–residual separation of gravity data

• Trend surface equation was further simplified using the matrix inversion method.
• Equations for easy calculation of the constants a, b, and c have been generated.
• The models were tested using a gravity dataset from Anambra Basin, Nigeria.
• A correlation of the results with existing software has proved their efficacies.

Trend surface analysis is a geological term for a mathematical technique which separates a given map set into a regional component and a local component. This work has extended the steps for the derivation of the constants in the trend surface analysis equation from the popularly known matrix and simultaneous form to a more simplified and easily achievable format. To achieve this, matrix inversion was applied to the existing equations and the outcome was tested for suitability using a large volume of gravity data set acquired from the Anambra Basin, south-eastern Nigeria. Tabulation of the field data set was done using the Microsoft Excel spread sheet, while gravity maps were generated from the data set using Oasis Montaj software. A comparison of the residual gravity map produced using the new equations with its software derived counterpart has shown that the former has a higher enhancing capacity than the latter. This equation has shown strong suitability for application in the separation of gravity data sets into their regional and residual components.