ALASKA-TREAD WELL MINE 6 1 



tween walls diminishes from about 400 feet at the pit level 

 to about 350 feet at the 440-foot level, and the thickness 

 of ore in the lower level is still further reduced by the 

 presence of two bands of barren syenite, one 50, the other 

 20 feet in width, and by a slate ' horse ' about 45 feet wide. 

 In other words, the ore body which at the pit level had a 

 thickness of about 300 feet has diminished by one-third 

 at the 440-foot level. It was expected by the superin- 

 tendent that drifting along the deposit would show this to 

 be only a local pinching of the ore-body, but whether this 

 expectation has been confirmed I am not informed. 



The portion of the Treadwell deposit lying next south 

 of the Treadwell mine and known as the ' 700 ' claim was 

 being exploited by an open cut in 1899, and ore was being 

 taken out to a width of about 100 feet. 



No work was being done on the Alaska-Mexican mine, 

 the next claim south, the mill being run on ore from the 

 other mines. 



At the southernmost of the developed claims, the Ready 

 Bullion, vigorous operations were being conducted, and 

 had shown that here the regular Treadwell lode was much 

 reduced in width, varying from thirty to not much over 

 sixty feet; but in the foot- wall of the lode a well-defined 

 quartz vein forty feet in width, dipping at a lower angle 

 to the west and carrying much higher values, was dis- 

 covered. Its relation to the main lode had not been 

 thoroughly developed by deep exploitation; but it seemed 

 to consist almost entirely of vein quartz, and thus to 

 differ essentially in origin from the larger replacement 

 deposits. 



Collections of ore and wall rock were made from all 

 the parts of the mine visited, and their study confirms the 

 results of Mr. Becker in all respects. The ore consists 

 of a somewhat silicified sodium-syenite, which has been 

 intruded as a large dike in the prevailing black slates of 



