the Peridotites in North Carolina. 55 



this on cooling. They are also prior to Yogt's* very impor- 

 tant investigations into the igneous origin of certain ore de- 

 posits. All these experiments have aided very materially in 

 solving the numerous problems in relation to the origin of 

 many of the ores ; and in the present investigation the facts 

 proved by these experiments have been of exceptional assist- 

 ance in the compiling of evidence to substantiate the theory 

 proposed. 



Evidence hearing on origin of Corundum. — In all the field 

 observations a careful search was made to find the corundum 

 directly in contact with the dunite, and this was observed at 

 one locality. At the Egypt mine, on the western slopes of the 

 Samson mountains, about ten miles west of Burnsville, in 

 Yancey county, several specimens have been found with the 

 corundum crystals entirely surrounded by granular dunite, and 

 showing none of the chloritic minerals usually present with 

 the corundum (fig. 3). Both the dunite and the corundum 



Fig 3. — Corundum costal in altered dunite. From Egypt, Yancey County. 

 One-half natural size. (Drawn from a photograph.) 



have altered somewhat, the corundum having a little musco- 

 vite developed on its basal termination, while the dunite is 

 stained a yellowish brown and is rather friable. The speci- 

 mens that were examined were collected by Mr. U. S. Hays, 

 who was prospecting in the vicinity of the mine, and were 

 loaned to the author by J. Y. Lewis,f who has described this 

 occurrence. There was no mining being done when this 

 locality was visited by the author, but miners living in the 

 vicinity, and who have worked in the mine, report the finding 

 of many fragments of corundum in the dunite similar to the 

 one here figured. 



Although this is the only locality where the corundum has 



* Zeitschr. fur Prakt. Geol., Nos. 1, 4 and T. 1893. 

 f N. C. Geol. Survey, Bulletin No. 11, p. 60. 



