242 T. A. BEN DRAT 



the scope of the region under discussion which is entirely composed 

 of granite. It is of the coarse-grained feldspathic type and exhibits 

 joints which run pronouncedly N. and S., E. and W., and N.W.- 

 S.E., and in no other direction. The backbone of the hill is a 

 quartz dike from 3 to 5 feet wide, which runs along the south- 

 western flank of the hill in a N.W.-S.E. direction. Assays made 

 of samples from this dike reveal traces of gold. Other quartz 

 dikes run parallel to this one as well as at right angles to it, while 

 near the top a dike of pinkish felsite about 2 feet thick and running 

 E.-W. stands out prominently from the surrounding coarse-grained 

 granite, which assumes a rather hornblendic aspect in the upper 

 levels. The flanks of the cerro, where slopes are gentle, and 

 only occasionally steep, are dissected by gullies and ravines running 

 parallel to the main quartz dikes in the main. 



About 26 km. S.S.E. of Caicara the Cerro de Morano rises above 

 the plain of the sabana in two distinct knobs which have heights 

 of 375 and 396 meters respectively above sea-level. Its topo- 

 graphic outlines seem to be determined by two main quartz dikes, 

 the more prominent one running N. and S., constituting the back- 

 bone of the cerro. Approaching the cerro from the north, one 

 encounters knobs and cliffs emerging from the sabana, which 

 consist of purplish weathering, coarse-grained feldspathic granite, 

 occasionally highly charged with iron oxides, and at places over- 

 lain by limited (in size) "banks" of ferruginous coarse-grained 

 sandstone. But the bulk of the cerro itself is made up of horn- 

 blende gneiss, which ranges from fine to coarse grained. The 

 average direction of lamination is N. and S., and N.W. and S.E. 



2. THE SABANA DEPOSITS 



In dealing with the deposits of the sabana, above which rise 

 the isolated cerros just described, one must distinguish between 

 the so-called "Laterite" deposit and what Dr. S. Passarge terms 

 "Upper Llanos" deposits. 



1. The "Laterite" deposit. — This deposit is a concentration of 

 iron oxide in a series of more or less fine and soft clays of a light 

 gray color. Deposits of this class have been found by Dr. S. 

 Passarge along the banks of the Cuchivero as well as the Caura, 



