Bulletin, Issue 6

alteration amphibole amphibolites anorthosites anthophyllite associated Bambawo basalt biotite biotite gneiss brown hornblende CALIFORNIA LIBRARY charnockites chlorite chromite clinopyroxene coarse coarser colour colourless composed composition constituent minerals contain crystals developed diaphthorites dolerite dykes dolerites dunites elongated emplacement epidote felspar ferromagnesian ferruginous foliation formation fracture frequently garnet geological geosyncline gneisses grade grains granulite facies granulites groundmass grunerite hornblende hornblendic rocks hypersthene hypersthene dolerites igneous interstitial Kambui schists Kasila gneisses Kenema Kenema Assemblage labradorite laterite laths lenses leucocratic mafic mafic granulites magnetite mainly Marampa Marampa schists marginal metacrysts metamorphism metamorphites metasomatism microcline migmatites muscovite myrmekite normally Northern Kambui area occur oligoclase olivine orthopyroxene pale green pegmatites pelitic plagioclase plateau pleochroic poikiloblastic porphyroblastic probably pseudomorphs pyroxene quartz Rokel Saionya Scarp schist belt schists sediments serpentine shear zones sheet 81 sheet 92 Sierra Leone sillimanite streams texture thin section tremolite trend ultramafic intrusives ultramafic rocks uralite varieties vary veinlets xenoblastic