398 NOTES ON THE CiEOLOGY 



is a gi'ay lithographic limestone, No. 485. At Erzeroum, a beau- 

 tiful gypseous alabaster, No. 487, is burnt and used as a substi- 

 tute for limestone. It is quaiTicd on the western branch of the 

 Euphrates, at Aih Kelly, from twenty-five to thirty miles west of 

 Erzeroum. It appears to be as beautiful and well adapted for 

 ornamental purposes as any that is used for vases, &c., in Italy. 



No. 484 is from the top of the first mountain ridge crossed in 

 going from Erzeroum to Trebizond. It appears to be compact 

 feldspar, from the ease with which it fuses, and is said to make 

 up most of the mountain, except now and then a granite peak. 



No. 435 is a pebble of siliceous slate, from the bed of the 

 western branch of the Euphrates. No. 477 is compact limestone 

 from Javislik, twenty-five miles south of Trebizond. No. 479 is 

 a concretionary mass of trap, or lava, from the same place ; and 

 No. 478 a trap tufa, or breccia, made up of angular fragments of 

 trap. Nos. 480 and 481, appear to be trap, with a stain of cop- 

 per ore, from a high summit not far from Madden, where the 

 Black Sea is just visible, in going toward Trebizond. In Mad- 

 den is a silver mine, wrought by Greeks ; and No. 488 is a spec- 

 imen of the ore. The trap specimens just named were obtained 

 not more than a few miles from this spot. No. 457 is from the 

 declivity just above the mine, and seems, so far as we can judge 

 from its lithological characters, to be graywacke slate. From 

 these facts, then, we draw these probable conclusions : first, that 

 this silver mine is in graywacke slate ; and, secondly, that igneous 

 agency has been in operation not far distant. This mine is fifty 

 miles southeast of Trebizond, and thkty-five miles northwest of 

 Erzeroum. 



Nos. 43G and 437 are fine specimens of pyritous copper, from 

 a mine fifteen miles east of Baiboot. The mine is ^\Tought by 

 Greeks, and it is said to be the most easterly point in Asia where 

 that people are to be found. A little east of the copper mine is 

 a very extensive deposit of dark serpentine, shown in No. 456. 

 This locality is on the second mountain ridge west of Erzeroum, 

 near forty miles from that city, and four miles west of the \dUage 

 of Roshapana. 



A high range of mountains is shown on the best maps, extend- 



