Lineaments Characterization and their Tectonic Significance in Mineralization using Landsat TM Data and Field Studies along Mambilla Plateau, Northeast, Nigeria

Abstract

Lineament characterization and their tectonic significance in mineralization using Landsat TM data and field studies Along the Mambilla  Plateau and environs, northeast Nigeria .The area forms part of the mineralized shear zone of the Northeastern, part of the Basement  Complex. The Basement Complex rocks underlie more than two-thirds of the plateau and date back to the Precambrian to early Paleozoic eras. While the remaining part of the plateau and its surroundings are made up of volcanic rocks of the upper Cenozoic to Tertiary and  Quaternary ages. Remote sensing imagery data and field measurements were integrated for mapping the structural elements and  hydrothermal alteration zones related to mineralization. Tectonically the lineaments trends NE-SW, NNW-SSE, NW-SE, and NS, are the  main trends controlling mineralization in the area based on data from remote sensing and field measurements. On the other hand,  applying band ratios and the constrained energy minimization (CEM) technique to Landsat-8 data pointed out alteration minerals  associated with the hydrothermal fluids. Silica, sericite, and chlorite are the common alteration minerals detected, while goethite and epidote are less common in the alteration zones of the area under study. A combination of CET structural complexity, circular features,  and alteration zones produced a potential mineralization map, pointing out numerous prospective zones for mineralization that are  proximate to areas where artisanal mining activities are carried out. The predictive map was validated by projecting the known prospect zones in the study area, reflecting an agreement between the known occurrences and the higher classes of the predictive zone. The  techniques in the current research can be adopted as a direct indicator for structural mapping and detecting alteration zones related to  mineralization elsewhere.