I visited this mound in company with Mr. Sam, who interpreted the name to be that of the gambogefruit. We descended, as we had ascended, by the stamping-battery, crossed the bridge, and then struck northwards, over the third hillock, to No. 4. Unlike Crocker's Reef, Aji Bipa does not show visible gold; its other peculiarities will best be explained by the report I wrote on the spot.
This property is situated near Crockerville and can always be easily reached from that place. In fact, the southern boundary marches with the northern limit of the Crockerville estate. The rich gold-bearing lode is situated on the western slope of the hill, and can be seen in all the three shafts which have been sunk. The formation of the hill seems in many respects to correspond with the Lingula flags at and near Clogau, Dolgelli, and Gogafau. This formation is practically the same as that of the range of hills on which the concessions of the Gold Coast Mining Company, of the African Gold Coast Mining Company, of the Effuenta Company, of the Mines d'Or d'Aboassu (Abosu), and the Tamsu concessions are situated, and also as that of Tebribi Hill; but each of the three areas has its own marked features. In all the rocks are talcose and show a sort of conglomerate of quartz pebbles, in some cases water-worn and in others angular, bedded in a mixture of quartz and granite detritus. This has in the three areas undergone varying degrees of pressure, and has been upheaved at different angles. In some cases the pressure and heat have been so great that the rock assumes a distinctly gneissic character.
At Aji Bipa the lode runs N. 38º E. (Mag.) in the centre shaft, and N. 40 E. in the southern shaft, a sort of fault occurring in the centre shaft. In the northern shaft I should put it at 38º, but from the way in which the neighbouring rock had cleaved it was difficult to get the strike accurately. The dip is the same in all three shafts, viz. 82º. The lode being so near vertical, it can be clearly traced for the whole depth of the shafts, and is very well defined. The hanging (eastern) wall is highly coloured with iron oxides, and contains many quartz crystals which are through-coloured with the same, and I do not think it at all unlikely that garnets and other gems may be found in it. One or two minute crystals showed a green colour, and might be tourmaline or emerald; but perhaps it was only a surface-colour caused by the presence of copper. The foot wall is very well marked by a strip of whitish yellow clay about an inch in thickness. The rock on both sides of the lode is gold-bearing, and is evidently, as well as the real lode, formed of the debris of old quartz and granites. Talcose flakes are frequent, and in some places it seems to be clearly gneiss. Although with a small plant it might not be profitable to treat this, still with large and suitable machinery it may be made to pay, and the trouble of separating the rich lode from the inferior stone avoided. One remarkable trait in the lode is the manner in which it splits into blocks and slabs, all the faces of the quartz pebbles being cloven in precisely the same plane.