110 Journal of the Mitchell Society [August 



ern part of JSTlorth Carolina and the northwestern portion of 

 South Carolina. Bordering these gneisses on the east, there is 

 a series of granites and other igneous rocks extending from 

 Cherokee County, South Carolina, across Mecklenburg, Ca- 

 barrus, Rowan, Davidson, Guilford, Caswell and Person coun- 

 ties, ]^orth Carolina, which have a general north to northeast 

 direction. At the extreme southern portion of ISTorth Carolina, 

 and extending into South Carolina, there is between these 

 granites and gneisses a band of metamorphic rocks consisting 

 of slates, schists, limestones, quartzites, and conglomerates 

 whose age is unknown. These occur quite extensively developed 

 in Cherokee County, South Carolina, and in Gaston, Lincoln 

 and Catawba counties, l^orth Carolina, and extend for a very 

 short distance into Iredell County, ISTorth Carolina. 'No more of 

 these rocks are observed in this northeast direction until they 

 again outcrop in the northeastern portion of Yadkin County, 

 extending nearly across Stokes County and almost to the Vir- 

 ginia line. They are in every way identical with those found 

 further South and represent the same geological formation. 

 Penetrating up into these rocks in Gaston and Lincoln 

 counties, E"orth Carolina, there is a mass of granite which is 

 from five to ten miles wide. The schists vary considerably in 

 character, sometimes being very siliceous and having a gneis- 

 soid structure. The general strike of these metamorphic rocks 

 is northeast; and it is in this belt of rocks in ISTorth Carolina 

 that the tin ore is found. The general strike of the pegmatitic 

 dikes and veins carrying the tin is approximately the same 

 as that of the metamorphic rocks, IT. 25° E., but near the 

 South Carolina line there is a rather sharp bend to the west- 

 ward, so that from there to Gaffney, South Carolina, the di- 

 rection of the tin belt is about K 55° E,., and it leaves the 

 schists to the east and passes through the Archean gneisses. 

 The rocks in the vicinity of Gaffney, South Carolina, are al- 

 most entirely gneisses, similar to those found in ITorth Carolina 

 to the west of the metamorphic rocks and which have been re- 

 ferred to as the Archean. There are, then, rocks of two dis- 

 tinct geological periods in which the tin veins have been found : 

 ( 1 ) Those associated with the Archean gneisses, which are found 



