/b FACTS IN AMKKICAN MINING. 



certain distance, while all the rest of the reef is barren. Where 

 several parallel reefs are found near each other, one may be rich in 

 gold for a considerable distance while all the others are barren, 

 and when the gold suddenly dies out it will not unfrequently be 

 found to commence in a parallel reef, but at a spot at right angles 

 with the point at which it has ceased in the previously prodneted 

 reefs. This phenomenon has been observed at Havvkin's Hill in 

 this Colony. In the same way that a chimney or shoot of gold 

 will be found to pass diagonally along a reef, leaving barren or 

 poor ground above and below, it not unfrequently happens that 

 other and sometimes richer shoots of gold are met with at greater 

 depth, having a certain parallelism to the first shoot.* 



Though soft and easy ground are most favourable for mining 

 exploration, it must not be supposed that payable mines only 

 exist under such conditions. In the Grass Valley the best mines 

 are found in a hard metamorphic slate, and the most productive 

 have generally been the narrowest. The production of gold from 

 this region has not been far short of five millions sterling ; and in 

 the best mines here the vein has rarely exceeded a foot to fourteen 

 inches. The size of the vein and character of the rock must not 

 therefore be looked upon as an infallible guide in the selection of 

 a claim. 



In regard to the peculiar distribution of gold, it is to be regretted 

 that science has done so little as yet to guide us in its search ; 

 but the next best guidance we can have, when the light of science 

 is wanting, appears to be in the accumulation of such facts as may 

 warrant us in drawing some general deductions, in the information 

 afforded by extensive experience, and in the wide publication of 

 results obtained from such experience. In mining generally it 

 may be admitted that much success is due to adventitious circum- 

 stances, but it is not the less true that we may derive much bene- 

 fit from the experience of others, both in knowing where reason- 

 able hope of success may attend the employment of capital, labour, 

 and skill, and not less where the waste of energy and skill may 

 be averted. 



One illustration of the peculiar way in which gold occurs may 

 be given by reference to the Sierra Buttes Mine, where the vein, 

 which is enclosed in hard metamorphic slate, varies in width from 

 6 to 30 feet ; the portion nearest the footwall only is productive, 

 and its average width, about 12 feet, alone is removed ; here at 

 750 feet the mine is as productive as at the surface. 



The different minerals found in the "Western States occupy 

 particular zones and belts, which are for the most part well marked ; 

 most of them follow the general course of some mountain chain, 

 or run in series of nearly parallel belts. The copper-bearing belt 

 is principally in serpentine — other magnesian rock, or metamorphic 



* The existence of gold on one side of the reef has been noticed in Gippsland, Victoria, 

 and elsewhere, la Jfew Zealand it is \?ry marked, at Heape's Creek, Thames Gold Field. 



