Mar. 1899. THE ORES OF CoLomMBIiA—NICHOLS. 155 
’ 
‘¢272. Quartzose porphyry, wall rock of all veins in Marmato.’ 
Quartz-porphyry, as used here, is equivalent to rhyolite. 
*©273. [E 1119.] Pyrite and blende, gold ore.” 
‘‘o74. [E 1120.| Pyrite and blende, gold ore.” 
These specimens are massive sulphides of iron and zinc. 
‘©275. [E 1209.] Pyrite and blende, gold ore.” 
“©276. [E 1647.] Pyrite and blende, gold ore.” 
This specimen has some decomposed rhyolite attached. 
‘277, Auriferous pyrites,”’ 
SILVER MINING DISTRICT OF SUPIA, IN THE 
DEPARTMENT OF CAUCA. 
A few miles southwest of _Marmato, upon the Supfa River, 
a branch of the Cauca, lies the town of Supfa. The ores of the 
district are blende and pyrite, in ‘‘ porphyry,” associated with “trap”’ 
and andesite. They are overlain by a sandstone, which is probably 
of volcanic origin. 
Here Sefior Gamba collected the following twelve specimens, 
representing two mines: 
‘¢278,. Porphyry, wall rock of the La Pava vein.” 
‘‘279. Sandstone [Zu | overlying the porphyry.’”’ 
‘280, Andesite, from Carbunio, near Supfa.”’ 
‘¢281. Trappean formation in Supfa.”’ 
‘282. Sandy veinstuff from La Pava mine.”’ 
‘283. Sandy veinstuff from La Pava mine.” 
“«284. Blende and pyrite, ordinary ore from La Pava mine.” 
©285. [E 1134.] Blende and pyrite, ordinary ore from La 
Pava mine.” 
‘286. Veinstuff with crystals of black blende, from La Pava 
mine.’’ 
(287. Pyrite and blende, schedderz from La Pava mine.”’ 
‘¢288. Pyrite and blende, schezderz from La Pava mine.’’ 
‘289, Ordinary ore, from La Pava mine.”’ 
‘290. Scheiderz from La Pava mine.”’ 
‘$291. Scheiderz from La Pava mine.” 
