The Gamp Fault again Lead Ore 



feature that we decided to land and make a closer 

 examination. 



Selecting a fissure about 12 feet in width, we 

 proceeded to clear away the earth and stones which 

 encumbered its mouth. This we found a more arduous 

 and dangerous task than we had anticipated, as on 

 disturbing the material a quantity of loose scree was 

 brought down from above. We therefore changed our 

 tactics, and introduced three dynamite cartridges, and 

 having attached detonators with a long length of fuse 

 to each, applied a light and moved off to a safe 

 distance. 



Having listened carefully in order to be sure that 

 all the cartridges had exploded, we returned to the foot 

 of the chimney and found that most of the weathered 

 material had been scattered far and wide over the 

 meadow, and that much of the upper part of the scree 

 had slipped down to fill its place, thus leaving bare a 

 face of the material in which the chimney was excavated. 

 An examination of the freshly-fallen blocks showed 

 them to consist of a mixture of Crystalline calcite 

 (CaCO 3 ), and Barytes or heavy-spur (BaSO 4 ), with 

 numerous masses of galena, a Sulphide of lead (PbS), 

 and crystals of Zinc blende (ZnS). On washing the 

 finer earthy material displaced by the explosion, it 

 proved to contain large quantities of galena and blende, 

 and as these are the principal ores of lead and zinc 

 respectively, we seemed to have struck a valuable find, 

 and one which might well repay further investigation. 



A stay of several days in this locality was indicated, 

 and as the weather was now decidedly warmer, and 

 our quarters on the launch somewhat cramped, a couple 



195 



