Mar. 1899. THe Ores or CoL_omBia—NIcHOLs. 137 
GOLD MINING DISTRICT OF AMALFI. 
Amalfi lies on the east bank of the Porce River, southwest 
of Remedios, on the road to Santa Rosa. It was founded in 1840, 
and, owing to its favorable situation, soon became a more important 
place than the older towns of Remedios and Zaragosa.. Its popu- 
lation in 1880, according to Reclus, was 6,600. It lies at an eleva- 
tion exceeding 4,750 feet,.and consequently is free from the tropical 
heat and consequent fever of the low-lying towns of the north. 
Mining of the veins began at about the same time as at Remedios. 
The deposits resemble those of Remedios, being quartz veins in 
pyroxene dacite, locally called granite, with intrusives of chloritic 
altered andesite or trachyte, locally called ‘‘hornblende,” and of 
a porphyritic rock. The veins are vetas de cajon, or veins steeply 
inclined to the horizon; and, therefore, differ from those of Remedios 
in some respects. 
Like those of Remedios, the ores are of the quartz-sulphide 
type. The pyrite of the Remedios deposits is here replaced largely 
by arsenopyrite, and the ores are in consequence very arsenical. 
From this district Sefior Gamba collected 22 specimens, repre- 
senting 12 mines, The series is as follows: 
‘¢66. Granite from Amalfi.” 
This specimen of the ‘‘granite of the later period” (Huméoldt) 
is unfortunately not in the collection, and consequently could not 
be verified. . 
The dacite of specimen No. 76, from a mine of this district, 
is a rock which cannot be distinguished from a granite by meag- 
scopic examination, and as no specimens of true granites are found 
in the collection, this will be considered as a pyroxene dacite until 
a specimen of it becomes available for examination. 
‘67. Wall rock from the Chuchero mine.” 
«68. Quartz, pyrite and arsenopyrite, ore from the Chuchero 
inunes: 
‘6g. Quartz and arsenopyrite, ore from the Chuchero mine.”’ 
‘¢70. Quartz, ore from the Chuchero mine.” 
‘¢71. Quartz, ore from the Chuchero mine.” 
‘72, Quartz, pyrite and arsenopyrite, ore from the Chuchero 
mine.” 
‘73. Quartz, pyrite and arsenopyrite, ore from the Chuchero 
mine.” | 
‘<74. Decomposed ore from the Lola mine.” 
‘¢7c¢. Decomposed ore from the Lola mine.” 
