330 Reports and Proceedings. 



of the so-called " Nuggetty Eeef," which is situated about 2^ miles 

 N.N.W. of the little town of Maldon, about 87 miles N.W. of Mel- 

 bourne, and consists of two strong quartz veins, separated by a mass 

 of bluish-grey metamorphic sandstone. In certain places the " reef" 

 is cut transversely or obliquely by granite bars or veins, of which 

 the author described four, and stated that although some of them are, 

 and all probably have been, connected with the main mass of granite, 

 they present rather the appearance of zones of impregnation than of 

 intrusive dykes, there being no line of separation between the quartz 

 rock and the granite ; but felspar and black mica make their appear- 

 ance in the quartz, and gradually increase in quantity until the 

 granite band is formed. The author noticed the following minerals 

 as associated with the gold in the " Nuggetty Eeef " — Iron pyrites, 

 arsenical pyrites, magnetic pyrites, copper pyrites, galena, zinc- 

 blende, and a compound of gold and bismuth, to which he gave the 

 name of Maldonite. 



3. '' On the Caratal Gold-field." By Dr. C. Le Neve Foster, F.G.S. 

 The author stated that the Caratal Gold-field is situated about 



100 miles south of the Orinoco, at a point about 75 miles above its 

 princijoal mouth. The rock of the district is chiefiy gneiss, with 

 some mica-schist, hornblende schist, and granite. The gold occurs 

 in four ways : — 1, in lodes, veins, &c. ; 2, in alluvial or " placer" 

 diggings ; 3, in red earth or " Tierra de flor ;" and 4, in gravel and 

 sand of river-beds. The mode of the occurrence of gold in these 

 different places, and the various processes employed in collecting it, 

 were described by the author, who estimates the quantities of the 

 precious metal obtained in the Caratal district as follows : — 

 In 1866 15,587 oz. 



1867 30,142 oz. 



1868 (9 months) . . 22,481 oz. 

 The greater part is obtained from the lodes. 



4. " On the Geology of Guyana in Yenezuela." By Ealph Tate, 

 Esq., Assoc. Linn. Soc, F.G.S. 



The author prefaced his remarks by pointing out the leading phy- 

 sical features of Guyana in Venezuela, and by alluding to the Geo- 

 logy of Venezuela to the north of the river Orinoco as determined by 

 Mr. Wall. 



Mr. Tate has ascertained the existence of an extensively deve- 

 loped metamorphic series, consisting of felstones, talc schists, quart- 

 zites, gneiss of great variety, hornblende slate, and amphibole rock, 

 striking about N.E. and S.W., and dipping generally to the N.W. at 

 a high angle. The series exhibits little disturbance, but great litho- 

 logical variation ; on the whole felspar predominates in the lower 

 part, whilst hornblende increases in quantity as we ascend in the 

 section. The felstone and talc schists, more especially the former, 

 contain eminently auriferous lodes ; the gneiss contains disseminated 

 gold, and that to the north of Upata a rich deposit of red haematite 

 and a few intrusions of greenstone. 



This metamorphic series was considered to be contemporaneous 

 with a similar series constituting the Littoral Cordilleras of North 



