THE STRUCTURE AND PETROGRAPHY OF THE NORTH-EASTERN PART OF NINGI-BURRA COMPLEX YOUNGER GRANITE PROVINCE NORTH CENTRAL NIGERIA, USING REMOTE SENSING TECHNIQUES

Abstract
The structure and petrography of the north-eastern part of Ningi-Burra Younger granite Complex of north central Nigeria was investigated using remote sensing techniques, field mapping, sampling and petrographic studies. This is in order to compile and interpret lineament and lithological features and to determine the sequence of structural events in the study area as well as correlate the result with the data compiled from previous workers on the Ningi-Burra Complex. A single scene of Landsat Enhanced Thematic Mapper plus (ETM+) data was georeferenced using the coordinates of the Nigeria Topographic Map Sheet 127 SE and 128 SW of Gwaram and Birnin-Kudu respectively, so as to delineate its lineament and lithological patterns. ERDAS imaging software was used for the satellite image processing, while image enhancement including (filtering and edge enhancement), as well as interpretation and digitization were carried out using ILWIS 3.3. After various image enhancement processes, the mapped lineament structures were interpreted as fractures, joints, drainage lines and dykes and ring structures. Analyses of the traced lineaments were conducted by visual and manual inspections, and the statistical results are characterized by positively skewed values. The total length of the interpreted drainage lineaments from the satellite images is 11.579 km with an average of 5.7895 lineaments per km and a data mean of 1.908 drainages per km. The interpreted fractures/joints lineaments have a combined total lineament length of 46.931 km, average of 23.4655 lineaments per kilometer, and a data mean of 1.456. The values of lineament density documented are 0.085, 0.086-1.70, 1.70-2.56, 2.56-3.41 and 3.41-4.26 square kilometer representing low, intermediate and high density values respectively. Values of the trend and/or strike of the interpreted lineaments were organized into bin sizes (class intervals), where each bin represents the number of values that fall within the specific angular region. The result of these structural analysis shows that numerous fractures and lineaments occur at the western, central and eastern part of the area on the satellite imagery. The common orientations of lineaments are NW-SE and NE-SW, while a dolerite dyke related to a major NE-SW striking fracture occurs in Western part of the study area. The study area is composed of rhyolite that commonly represents the earliest igneous activity and is intruded by porphyries, granites and less commonly by syenites. The rhyolites include lavas ash fall tuffs and agglomerates, as well as abundant ignimbrites that were deposited from ash flows (synonymous with ash-flow tuffs), including both welded and non-welded tuffs. The magmatic cycle in the studied north-eastern part of Ningi- Burra Younger Granite ring complex occurred repeatedly, with the location of magma generation migrating progressively westwards, resulting in a chain of rhyolitic cauldrons. It is also revealed that localities with high lineament density within the study area are mineralized with topaz and cassiterite deposits.
Description
A DISSERTATION SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF MASTER OF SCIENCE IN GEOLOGY DEPARTMENT OF GEOLOGY, FACULTY OF PHYSICAL SCIENCE, AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA
Keywords
STRUCTURE,, PETROGRAPHY,, NORTH-EASTERN, NINGI-BURRA COMPLEX,, YOUNGER GRANITE,, NORTH CENTRAL, REMOTE SENSING TECHNIQUES,, NIGERIA
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