Mar. 1869. THE OreES OF CoLtomBia—NICHOLS. 167 
SILVER MINING DISTRICT OF VENADILLO. 
Venadillo, on the Venadillo river, is southwest of the city of 
Ambalema and northeast of Ibague. Gold was obtained from pla- 
cers on the Venadillo river at a very early date and by 1625 the place 
which had become an important mining center, was practically 
deserted because of depredations of hostile Indians. The first 
account of the recent workings is by Restrepo, who reports in 1886 
that some miners from Antioquia had extracted gold there ‘‘within 
the last few years.”” This gold was evidently obtained from placers 
and the silver mines were opened later. The ore is pyrite and galena 
in quartz. From Venadillo, Senor Gamba collected the two follow- 
ing specimens, representing one mine: 
‘¢ 387. Pyrites and galena, schetderz from the Palmillo mine.” 
‘¢388. Pyrites, ore from the Palmillo mine.” 
GOLD AND SILVER MINING DISTRICT OF IBAGUE. 
Ibague, the capital of Tolima, is situated at an elevation of 4,270 
feet on a plain which is surrounded by spurs from the volcano of 
Tolima. It is on the banks of the Combeima, an affluent of the Mag- 
dalena river. The crater of Tolima is twenty miles to the northwest. 
The population of Ibague is, according to Reclus, 13,000, and accord- 
ing to another estimate, 10,000. As the important interests of the 
city, like those of Manizales, are other than mining, the size of the 
place is no index of the importance of the mines. Founded in 1551, 
at the same time as San Sebastian de la Plata and Mariquita, it was 
for many years the center of an important mining industry which 
nearly disappeared with the general decline of mining in Colombia at 
the close of the sixteenth century. The ores, like those of the other 
districts of Northern Tolima, are sulphides of iron, lead and zinc in 
quartz. The zinc is the most abundant and the lead the least. The 
richer ores contain tetrahedrite and in most respects closely resemble 
those of the Santana districts. Tolima is an andesite cone on a ped- 
estal of mica schist and slate. The mica schist and slate are reached 
in the Frias, Sonrisa and other mines of the Marequita districts. The 
ores of the Ibague are in andesite and its schistose chloritic altera- 
tion products. The local names of the rocks in which the ores occur 
are syenite, granite, hornblende, schist and black or ‘‘ negro-negro” 
schist. These schists are chloritic, schistose and metamorphic ande- 
