Thp Lower Essequiho River and Cuyuni River District. 119 



source in some low hills near the river, and a few small placers are 

 being worked on the creek and its branches. The placer-gravels 

 mainly consist of angular fragments of quart/, with some ironstone- 

 pebbles. Here and there in them oblong blocks of a more or less 

 partially decomposed fine-grained hornblende-schist are found. 



While the general course of the Groete Creek is from the north- 

 east, its tributary creeks, the Black Creek and the White Creek, flow 

 with very tortuous courses into it from a westerly and south-westerly 

 direction. 



The Black Creek flows in several places between its mouth and 

 Black Creek landing over beds of ironstone conglomerate and 

 ironstone gravels. These, as a rule, occur off" spurs of higher ground 

 which descend to the stream. About two miles, as the crow flies, 

 from its mouth, and half a mile below the placer landing, there 

 is an exposui'e on its right bank of a white mica-schist. The placers 

 near Black Creek landing are worked in angular quartz gravels, 

 and, like those at Salt Creek, contain in places in the gravel 

 oblong pieces of fine-grained hornblende-schist or of epidote-horn- 

 blende-schist. About a quarter of a mile up the creek from the placer- 

 landing, at a lock belonging to the wood-cutting grants further up the 

 stream, a section is exposed in an excavation in decomposed gneiss. 

 The lower parts of the cutting show in the residuary products well- 

 marked signs of the foliation of the original rock, the layers being of 

 various shades of red, brownish-red and yellow, while some are white ; 

 in the higher part the signs of foliation disappear, the upjDer layers of 

 the argillaceous earths becoming of a uniform ochreous hue caused 

 doul)tless by repeated deoxidation and reoxidation with attendant 

 redistribution of the hydrated oxide of iron, upon the presence of which 

 the colour depends. About a quarter of a mile above the lock large 

 exposures of a dark-coloured augite-granitite occur. Similar exposures 

 are seen in places for a mile up the creek, the rock varying in character 

 from an augite-granitite to a hornblende-granitite. At one exposure 

 the rock is intersected by veins of pegmatite about three inches across, 

 which gradually change into quartz veins, and by thin veins or tongues 

 of fine-grained grey granite. About half a mile above this an 

 exposure shows a massive augite-granitite underlying a decomposing 

 grey gneiss. About a quarter of a mile farther on, and for about half 

 a mile along the course of the stream, grey gneiss of somewhat 

 varying textures occurs. Near Matthew's wood-cutting grant masses 

 of coarse-grained granitic-gneiss are seen, and these occur at intervals 

 for probably from a mile to a mile and a half above the grant. 



The Groete Greek and Cuyuni Trail. — This path commences at the 

 placer landing on the Black Creek, and leads, in a general direction 

 somewhat south of west, round and in places over the spurs of low 

 hills, the heights of which vary from 150 to 200 feet above the level of 

 the creek, to the group of placers on the White Creek near the foot of 

 the hill termed by the gold diggers " PuU-and-be-damned Mountain," 



