THE PETROLOGY, MAJOR ELEMENT GEOCHEMISTRY AND MINERALIZATION OF THE GANAWURI YOUNGER GRANITE COMPLEX, NIGERIA
THE PETROLOGY, MAJOR ELEMENT GEOCHEMISTRY AND MINERALIZATION OF THE GANAWURI YOUNGER GRANITE COMPLEX, NIGERIA
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Date
1996-11
Authors
EFFIOM TARH, EMMANUEL MFONGANG
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Abstract
The Ganawuri Complex, mapped on a scale of 1:25,000, is one
of the androgenic granite Pluto occurring within the central axis
of the Nigerian Younger Granite Province. This complex comprises
several granites of biotite, hornblende and fatality composition,
with the biotech - bearing ones being predominant. The granites
have near vertical contacts at their boundaries with the rocks of
the Basement Complex, while being of lower angle to near horizontal
with successive granite phases.
Joints follow a generally WNW-ESE pattern, which is also the
dominant regional trend. Their combined action on the rocks has
resulted into rectangular slabs covering a good portion of the
entire area.
The lithe-units show a certain consistency in their
mineralogy, with their major constituent minerals and accessory
minerals varying only slightly.
Peripatetic microcosmic and albeit occur, alongside quartz,
biotech and hornblende in the earlier phases, while orthoclase and
fatality occur in the later phases.
Geo-chemically, the rocks are silica-rich, and their alkali
content increases with the sequence of emplacement. There is a
general trend of a decrease in Si02 with an accompanying
enrichment in alkali content. Also evident is a depletion in Fe203 in
favor of MgO, an abundance of soda over potash and a consistent
excess of alumina over the alkalies. The original magma must have
been peraluminous, and derived from partial melting of Basement
rocks. Three separate phases of magmatic activity have occurred:
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the first initiating the hornblende - biotech - granite; the second
starting with the hornblende-fatality-granite and the final phase
being the intrusion of dykes.
Tin mineralization in the Ganawuri Complex is in the form of
Cassiterite, now exploited as secondary deposits in river
sediments, which have resulted from erosion of quartz-rich veins.
The latter constitute the primary mineralization and resulted from
fracture-controlled, geneticist processes
Description
A Thesis submitted to the Postgraduate School,
Ahmadu Bello University, Zaria in partial
fulfillment of the requirements for the Degree of
Masters of Science in Geology (Mineral
Exploration)
Department of Geology,
Faculty of Science,
Ahmadu Bello University, Zaria
NOVEMBER, 1996
Keywords
PETROLOGY,, MAJOR ELEMENT, GEOCHEMISTRY,, MINERALIZATION,, YOUNGER,, GRANITE,, COMPLEX.