The crustal structure along the Mbere trough in South Adamawa (Cameroon) from spectral analysis and gravity modelling

The Mbere Cretaceous trough is located in the southern part of the Adamawa province. A gravity interpretation based on data obtained from three NW-SE profiles on the residual anomaly map has been carried out using a 2.5D modelling program. Spectral analysis has been used to estimate the depth of geological structures. The results obtained show that the metamorphic formations consist of gneiss and migmatite which are located in the north of the trough at a mean depth of 9 km. The gradient observed on the Bouguer anomaly map along the trough might not only be due to the northern fault but also due to the contact between the gneiss (and migmatite) and granite under the trough. The thickness of sediments along the trough varies between 1500 and 2250 m with a minimum at Yariban and a maximum at Djohong. The trough is bounded on its sides by faults related to the Central African Shear Zone. Basaltic rocks associated with the Cameroon Volcanic Line are present as intruded rocks lying at a minimum depth of 7200 m. Keywords: bouguer anomaly, residual anomaly, fault, trough Global Journal of Pure and Applied Sciences Vol. 12(1) 2006: 111-11

A Turbo Pascal 7.0 program to fit a polynomial of any order to potential field anomalies based on the analytic least squares method

An anomaly separation program for gravity (or magnetic) data in prospecting domain is presented. It can be applied to the gravity or magnetic anomaly separation of degree up to three and allows the management of up to 1200 data. Its implementation requires a Turbo Pascal surrounding through a TP7 list on the main root of the computer. The results obtained after execution of the program can be displayed, printed or stocked in a data file. In order to test the program, we have compared our results with those obtained from a Fortran program written by Radhakrisha and Krishnamacharyulu (1990) using the least squares method. The advantage of using our program is that a great number of data can be handled even for a local study, the execution is rapid and the accuracy is greatly improved upon. African Journal of Science and Technology Vol.4(2) 2003: 1-