Geochemical exploration around the pegmatitic Sn-Nb-Ta mineralization of Southwest Nigeria


Author : G. MatheisPublication : Bulletin of the Geological Society of MalaysiaVolume : 11Page : 333-351Year : 1979


Description

Bulletin of the Geological Society of Malaysia, Volume 11, Dec, 1979, pp. 333 – 351

 

Geochemical exploration around the pegmatitic Sn-Nb-Ta mineralization of Southwest Nigeria

G. MATHEIS*

Department of Geology, University of Ife, lle-Ife, Nigeria

*Present address: Geologisch-Palaonatologisches Institut der Justus-Liebig-Universitat,
Gies sen, Senckenbergstrasse 3, D-6300 Lahn-Giessen 1, Federal Republic of Germany

 

Abstract: A metallogenetic belt of pegmatitic Sn-Nb-Ta-mineralization stretches for about 400 km in Southwest and Central Nigeria with only a few sites where active mining occurs. To explore other parts that may have additional economic mineralization, a geochemical orientation survey was initiated in Southwest Nigeria in three areas of alluvial small scale mining.

At the reconnaissance level, a geochemical stream sediment survey indicated cold extractable Li as the most useful indicator for outlining mineralized pegmatitic source rocks. A heavy mineral survey at the same scale proved to be very inconsistent due to the lack of a well developed perennial drainage system; its application should be restricted to the last stage of detailed surveys.

A geochemical soil survey with a density of 1 sample per square kilometer around the former mining area of Ijero indicates that the best reflection of the pegmatitic parent rocks are given by the elements Mg/Li, Li, Rb, Cs, Be in decreasing order of significance. Interpretation of all five pathfinders will render the best results.

Investigations of F as an additional pathfinder and the application of the presented methods in the mining area of Egbe were made.