The cycle of igneous activity was initiated by a volcanic phase during which large volumes of rhyolitic lavas were extruded.
Younger granite of nigeria.
The ring dikes tend to be highly mineralized and enriched in niobium and tin.
The younger granites are primarily alkali feldspar granites although the ring complexes also include rhyolite gabbro and syenite.
They are dominated by granites and are emplaced in pan african basement rocks on swells bordering sedimentary basins.
The younger granites the mesozoic younger granite ring complexes of nigeria form part of a wider province of alkaline anorogenic magmatism extending from northern niger republic to south central nigeria.
Other occur rences approximate a north south belt towards the middle benue in the south where the ages are younger and towards niger republic in the north.
1 and 2 k feldspars from fayalite hedenbergite granite and porphyry.
Migmatite gneiss migmatite gneiss the schist belt and older granite and younger granite complexes and all of these are seen in different location of the studied area.
The younger granite ring complexes of west africa extend from air to cameroun and range in age from palaeozoic to tertiary.
Rare earth patterns of k feldspar separated from granitic rock of younger granites of nigeria.
Sufficient information is now available to indicate that the province includes some of the finest examples of granitic ring complexes in the world.
Bibliography on the younger granite ring complexes and tin mineralization in west africa with emphasis of nigeria.
Careful examination of the younger granite complexes of this province as seen on the 1.
Vii of the society s memoir no.
This memoir presents a summary of recent studies on the nigerian younger granite complexes.
Journal of african earth sciences 1983 vol.
They occur in a zone 200 km wide and 1 600 km long extending from northern niger to south central nigeria.
2 000 000 geological map of nigeria or on pl.
5 and 6 k feldspars from barren biotite granite 7 8 and 9 k feldspars from stanniferrous biotite granite.
3 and 4 k feldspars from has tingsite biotite granite and porphyry.
Journal of african earth sciences 1983 vol.
2 1 form part of a wider province of alkaline anorogenic magmatism.
The younger granite complexes in nigeria are found mainly on the jos plateau forming a distinc tive group of intrusive and volcanic rocks that are bounded by ring dykes or ring faults.
1 shows also that these four planes of weakness appear to have exercised a significant control in the emplacement of the younger granites.
From this description of rocks units and also the younger granite intrusion.
The nigeria basement complex have been conformed to comprise of three major rock units of which are.
Sedimentary basins the cretaceous to recent basins in nigeria include.