the Peridotites in North Carolina. 



59 



serainated through it ; f, another zone of the green chlorite ; 

 g, mass of interlocking bladed grayish crystals of enstatite that 

 merge into h, a fibrose talcose rock which passes into i, an 

 altered dunite that is somewhat friable and stained with ferric 

 oxide ; j, hard and apparently unaltered dunite. Between h 

 and i a mass of soft, yellowish clay, o, containing fragments of 

 chalcedony. 



The line of contact between the zone of alteration products 

 and the gneiss was very sharp and distinct in all the contact- 

 veins examined. The minerals developed between the corun- 

 dum-bearing zone and the dunite are of great abundance and 

 different from those between this zone and the gneiss. 



In a cross-section of a dunite-vein at a shaft near the south- 

 ern part of Corundum Hill, in a distance of from 20 to 25 feet, 

 the following has been observed : 



1. Dunite, hard and apparently unaltered. 



2. Dunite, somewhat friable and discolored, passing into 3. 



3. Talcose rock, fibrous, merging into 4. 



4. Enstatite, grayish and somewhat fibrous. 



5. Green chlorite, 6 to 15 inches in width. 



6. Green chlorite, corundum and spinel, 6 to S feet wide. 



7. Chlorite (same as 5). 



8. Enstatite (same as 4). 



9. Talcose rock (same as 3). 



10. Dunite (same as 2). 



11. Dunite (same as 1). 



The similarity of the two parts of the vein, each side of the 

 corundum zone, as described above and illustrated in fig. 6, is 

 verj apparent. 



G 



11 10 9 8 7 



In fig. 6, 1 and 11 represent the apparently unaltered du- 

 nite ; 2 and 10, dunite somewhat friable and stained and pass- 

 ing into 3 and 9, a fibrous talcose rock, often carrying a green 



