Geology and Mineralogy. 59 



Since the deposition of ore there has been no disturbance at all 

 comparable to those which preceded this deposition. The asso- 

 ciated dikes too are little disturbed. The greater part of the 

 gold is certainly Paleozoic or older, for the Newark sandstones 

 contain transported gold. There is no known disturbance in the 

 Paleozoic which would answer in intensity or vulcanicity to those 

 mentioned. These facts and such evidence as is available concern- 

 ing the age of the ancient eruptives point to the Algonkian as 

 the age of gold deposition. The slaty cleavages are older than 

 the quartz veins and they are mechanically equivalent to distrib- 

 uted orogenic dislocations. Thus they indicate that as far back 

 as the Algonkian a range or ranges existed which belonged to 

 the Appalachian system. It will not be surprising if the tendency 

 to mountain-building along this trend, which has manifested 

 itself in the Pleistocene, should be detected even in the Archaean. 



The report contains a long list of " gangue minerals " with 

 localities and literary references. No less than sixty of these 

 minerals are recorded, including, however, the sulphides as well 

 as the earthy salts. The propriety of using the term gangue to 

 include those metallic minerals which are not ores of the metal 

 sought is open to question, but the term is very convenient and, 

 when discrimination is requisite, it is easy to specify earthy 

 gangue or metallic gangue. The conclusion reached from study 

 of the ores is that " the gold ores of the South are quartzose 

 deposits with very subordinate admixtures of carbonates in which 

 pyrite is always present, while chalcopyrite is common, and 

 galena, mispickel, and zincblende are by no means rare. The 

 long list of other minerals found in the veins is unimportant, 

 excepting in so far as it assists in elucidating the genesis of the 

 ores." The gold ores of the South are thus substantially like 

 those of most auriferous regions. 



The quartz veins of the southern Appalachians have been 

 regarded by several previous observers as beds contemporaneous 

 with the rocks, but W. B. Rogers early pointed out that the con- 

 formity between the veins and the rock laminae is only approx- 

 imate. This important observation is fully borne out, and it 

 appears that the structure with which the quartz is often approx- 

 imately conformable is not bedding at all, but slaty cleavage. 

 Almost everywhere the veins occasionally break across from one 

 parting to some parallel one, and in most cases angular fragments 

 of slaty wall rock occur imbedded in the quartz. Many of the 

 deposits are not solid veins but zones of small lenticular veinlets 

 separated by thin sheets of slate. For these the term, stringer- 

 lead is proposed, since they do not answer to the definition of a 

 vein, which is "the filling of a fissure." No evidence of replace- 

 ment was detected in these deposits, which seem to occupy only 

 openings due to fracture. In many cases, However, the slate is 

 impregnated with auriferous sulphurets tor some inches from the 

 quartz. 



