116 The Geology of the Gold Fields of British Gitiana. 



considerable beauty, and it is to be regretted that the structure of 

 the coastlaiids prevents use being made of this handsome stone for 

 pubHc buildings. 



Almost opposite to Ithaka, on the left bank of the river at 

 Saxakalli Point, and somewhat further south at Karati Point, 

 masses of quartz are visible near the edge of the river. This 

 quartz is dark in colour, in parts schistose in structure, and contains 

 in places small veins of earthy black oxide of manganese, and 

 in others nests of massive psilomelane. Near by a shaft has been 

 sunk in the hopes of obtaining graphite in payable quantities. No 

 graphite was met with in the shaft, and masses of hard, gritty, black 

 schistose material veined with calcite obtained from it proved on 

 examination to be quartz, cemented and coloured by black oxide of 

 manganese. On the top and slopes of the low hills in this vicinity 

 boulders of white glassy quartz are scattered fairly fi*equently. The 

 quartz from Saxakalli Point yielded upon assay 1-7 dwts. of gold per 

 ton of the rock. Gneissose rocks are said to be exposed at Saxakalli at 

 low water. 



On the left bank of the Essequibo there are exposures of gneiss, 

 generally a medium- textured grey variety, in many places between 

 Saxakalli Bay and Gold Mine at Patientia. Near and at Patientia the 

 banks of the river consist of decomposed gneiss, in places, having the 

 appearance of stratified arenaceous and argillaceous earths. The layers 

 are of many shades of colour varyiiig from almost white and cream- 

 coloured through buff and light-red, bright-red and dark-red to a 

 cinnabar-like purplish-red. In many places, especially in certain of 

 the deeper-coloured layers, the sandy ochreous earth contains abundant, 

 very minute, scales of a glistening white, hydrous mica. If this earth 

 is puddled in water the glistening scales separating out much resemble 

 very minute globules of quicksilver ; or, if the earth is rubbed between 

 the fingers the mica scales adhere to them, and somewhat resemble 

 floured or " sick " mercury. This has doubtless given rise to the 

 rumour that there are deposits of cinnabar and of native mercury at 

 Gold Mine, whereas the banks there consist of a decomposed basic mica- 

 schist or gneiss. 



The adit known as " The Gold Mine " appears to have been driven 

 through similar material in the hopes of intersecting a quartz reef ; and 

 many fragments of quartz are found on the low hills near it. 



In addition to the rumoured deposits of cinnabar and mercury, it is 

 alleged that a seam of coal exists near Patientia. The foreshore of 

 the river at and near Gold Mine certainly is rich in pieces of coal, and 

 this mineral is present in some quantity in the shallow channel between 

 Patientia and the Pairuwa Islands. But, besides coal, pieces of chalk- 

 flints and other specimens, the origin of which, undoubtedly, has been 

 ballast which has been thrown from shij^s, are fairly plentiful. The 

 greater I3art of the coal has doubtless had a similar origin, many of the 

 ships which load with timV)er in the vicinity arriving in the colony with 

 cargoes of coal, and the remnants of these are thrown overboard whilst 

 loading. There is, in addition, the wreck of a large ship in the river 



