208 L. V. Dalton — Geology of Venezuela. 



As associated phenomena may be mentioned the hot springs, also 

 confined to the region of the Cordilleras. Tlie most notable is that 

 of Las Trincheras, between "Valencia and Puerto Cabello, where the 

 waters reach a temperature of about 195° F. or even 206° (Karsten, 

 1852); these springs rise througli the schists and gneisses of the 

 Caribbean Series, and they contain large quantities of sul[)hur. 

 Throughout the Cordilleras many hot springs are known, and 

 southwai'd of Carupano one was found by Wall to be at boiling-point, 

 wliile in the Andes the springs, tliough numerous, have in general 

 a low temperature. 



V. Economic Minerals. 



On the side of economic geology Venezuela cannot be said to have 

 been explored in more than a superficial way, leading in the first 

 place to exaggerated ideas of the wealth of the country, in the 

 second to an almost equally unfortunate lack of appreciation of the 

 possibilities of its mineral wealth. 



Coal has been worked at several points, though most extensively in 

 the mines of Naricual, near Barcelona ; the seams found appear to be 

 Tertiary for the most part, and there are also Cretaceous coals. The 

 Segovia Group may be the source at Naricual, as it is in Lara, but 

 there is some doubt as to the age, and tlie Cerro de Oro Group is 

 equally possible ; in the Andes the latter has coals at many points, 

 and there are lignites of high quality, as well as coals, in the Curaana 

 Series of the Coro and Maracaibo region. Iron ores have been found 

 in many places and in locks of every group, but have not been con- 

 sidered workable ; the deposits of magnetite in the Guayana gneisses 

 on the Rio Imataca seem to be of a size to warrant exploitation, and 

 the ore is said to contain 65 per cent or more of metal. 



Gold, as the metal which originally attracted European adventurers 

 to explore tliese regions of South America, may be said to occur in 

 almost every State of Venezuela, but generallj- in quantities too small 

 to be more than a curiosity. Wherever the Caribbean Series forms 

 the mass of the Cordilleras, occurrences of gold-bearing quai'tz are not 

 uncommon, and near Carupano lodes have been found to yield 7 ounces 

 to the ton. When Sir Robert Dudley visited the Paria coast in 1595 

 he heard of a gold-mine near Omcoa (Uracoa), on the eastern border 

 of the Llanos, which may possibly have referred to gold-bearing 

 gravel there, but the source of the commercial gold has always been 

 the Guayana region, principally round the head-waters of the Cuyuni 

 in the neighbourhood of Gnacipati. Here auriferous gravels chiefly 

 have been exploited, but the metal is derived from the Archaean 

 immediately below. In British Guiana, where the conditions ai'e 

 similar, Mr. Harrison says that the gold is generally found along the 

 basic intrusive dykes, and the veins are particularly ricli where these 

 traverse the older quartz-porphyries and felsites ; the best are found 

 near the smaller dykes. 



Copper is widely distributed in the Noi'thern Cordillera, and has 

 been worked for many years at Aroa, where the veins of pyrites 

 occur in metamorphosed limestone (? Capacho). At Seboruco in 

 Tachira, in the neighbouihood of Balladores in Merida, and at many 



