Contribution of Remote Sensing for the Mapping of the Yaoundé Metadiorites

Abstract

Geologists face a number of problems, mainly related to the difficulty of covering the entire terrain, leading to various pieces of information collected and its extrapolation for drawing maps. To overcome these problems, we have proposed to use remote sensing which is a current tool for rock mapping. Remote sensing is a modern tool to highlight several information that conventional mapping methods do not allow. Thus, the objective of this work is to update the geological contours of the Yaoundé metadiorites by processing satellite images coupled with the classical approach. Sentinel 1-A radar images were used. A textural analysis of these images was carried out using the GLCM (Grey Level Co-occurrence Matrix) method, resulting in eight co-occurrence indices, among which three were chosen to perform colored compositions. The colored compositions obtained are VMH and HMV. And the contrasts obtained were compared with maps from previous work and also with field work. The metasedimentary rocks (kyanite - garnet migmatites and garnet micaschists) and metaigneous rocks (metadiorite) constitute the metamorphic complex distinctly mapped by exploiting remote sensing data, superposition maps from previous work and integrating the new sampling points. Remote sensing in geological mapping thus plays an important role mainly in the urbanized study area as it detects the metadiorites under the metasediments despite the existence of anthropogenic works and low vegetation cover.