60 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bull. 213. 
nary methods. Dredging the river bottoms is, however, still profitable, 
and is carried on as explained by Mr. H. V. Maxwell in the interesting 
paper cited above. In the present article the placer deposits will not 
be further discussed, attention being confined to the gold-quartz veins 
of the district. 
From the point of view of the miner, the gold-quartz veins can be 
separated into two distinct classes, requiring very different treatment, 
both in the mine and in the mill. As is well known, the rocks in this 
portion of the southern Appalachians are very deeply weathered, and 
in many places solid rock does not occur within 100 feet of the surface. a 
In this zone of decayed rock — which on the average includes the 
upper 50 to 100 feet — both the country rock and the vein material are 
disintegrated, and resemble sand or gravel in texture and consistency. 
The two important effects to the miner of this deep weathering are 
that (1) the ore itself is free milling, the pja-ite having altered to 
limonite and released its gold; and (2) the entire mass of material 
can be mined and treated exactly like a thick placer deposit, by 
hydraulic mining. At present hydraulic mining is being carried on 
extensively in the Crown Point, Singleton, and Tahloneka properties, 
the material being washed into sluices by the giants and carried in 
this manner direct to the mills. 
In a proposition of this character such a combination of soft 
material and free-milling ore renders the cost of mining and milling 
very low, and even low-grade ores can be profitably worked. The 
ease of working is, however, partly offset by the fact that a large 
amount of worthless material is washed out by the giants and sent to 
the mill along with the profitable matter. 
As soon as the zone of weathered rock is passed in depth the work- 
ings eneounter solid rock (mica-schists, etc.) containing fairly distinct 
veins of gold-bearing quartz. In this hard material it is possible to 
mine only the vein, thus reducing the handling of worthless material to 
a minimum. This advantage over workings in weathered rock is, how- 
ever, much overbalanced by the two considerations that in deep 
mining in solid rock (1) the cost of mining, per ton of material moved, 
is very much higher than in soft material, and (2) the ores no longer 
carry ai^ very large proportion of free gold, for the pyrite is not 
decomposed. Simple stamping and amalgamation is therefore insuffi- 
cient, and some more expensive process must be substituted. Numer- 
ous "secret processes" have been tried without success. Chlorination 
is now practiced at two plants, but the results are not entirely 
satisfactory. 
Relations of the gold-ore deposits. — Since the visit of Dr. Becker to 
this district, in 1894, the mine workings have been deepened, and in 
a Becker suggested the use of the term "saprolite" for material such as this, which is the 
product of rock decay in place. Unfortunately "saprohte " has, in the Dahlonega district, been 
adopted by the miners and used in a sense entirely different from that intended by Becker. For 
this reason the term will not be used in the present discussion. 
