Show GEOLOGY OF TONOPAH MINES the mineral bearing formation at tono pah extends south from the city for a distance di siance of probably fourteen miles and about the same distance in the opposite direction in width the belt is estimated as being from six to eight miles this opinion is also concurred in by mr B R A vaughn a well known mining expert who recently gave the district a critical examination in summing ing up other geological conditions he says in a contribution to the tonopah miner the ithe formation has a crystalline cry structure wherever mineral has been found the general mass of country rock being rhyolite with a superimposed porphyry overflow which extends east and west with volcanic lime lying to the southeast on the southwest basalt on the northeast sr anite and on the northwest volcanic and sediment tary aggregations that have been carried from the mineral bearing range 11 with the exception of the spot on mizpah lode where it presents itself on anthe atie surface the overflow covers the whole country completely obscuring any trace of ledges and for that reason everyone has 9 gone at it blind when it came to sinking siu king but whenever the blue lode of porphyry underlying der lying this overflow is encountered it is a pretty sure thing so far as developments have been made that pay ore will be struck this overflow varies in thickness in the montana Tono tonopah To the blue porphyry was cut into at ninety one feet other companies have had to go more than feet before getting through with the substance left by the overflow |