Show THE GEOLOGY gee OF ROCHESTER CANYON ta by D P D R wat little or no detailed study of the geology of rochester has been made field notes habitually taken by inquiring minds that unconsciously seek the causes of things have been published discussions between miners and prospectors have been heard reckless predictions of future productions have been offered grave and deliberate guesses with prophetic bias have been circulated cu but systematic and continued study starting with some definite premise and followed to a practicable conclusion has not become common property defending himself from probable and justifiable attacks invited by deficiencies in the following notes on rochester in general and nenzel hill in particular the writer desires to note a recent public utterance of two noted nevadans Nev adans whose irregular orbit girdles the western mining world the occasion for the remarks is of no moment the declaration was in effect that geologists came in at the post mortem and never at the birth of a mine that a geologist never yet has found nor made a mine in such a record wholly innocent of the semblance of useful usefulness ness the following notes may find a worthy tomb rochester is a district covering several square miles say twenty of the economic minerals gold and silver predominate lead and copper minerals are found but in negligible quantities within this area are two prominent and important peaks prominent by natural selection and important by reason of a value measurable in dollars and cents by reason of a remarkable production during the four brief months of its history nenzel hill hild demands first consid aeration era tion the procedure usually followed in the discovery of a mine was repeated here float was found strewn on the hill sides float of a value that permitted of shipments being made that yielded encouraging profits parts of the base of nenzel hill fall anto into three canyons weaver on the south I 1 1 11 rochester ochester on the west and Al american merican on oil ithe athe I 1 east from these canyons slopes rise 1 abruptly and are covered with detritus t rock exposures that mark the peaks and I 1 bridges determine and limit the field avail i lab ab e for geological interpretation the pre t 1 availing rock ock on nenzel hill is light colored and A material sis lis known but are abundant lack composition is significant ore specimens reveal so frequently original through the veil of secondary silica that the idea of having fo followed bowed abines lines of high feldspar content is suggested mining alining engineer east rochester nevada the prevailing westerly dip of approximately 60 degrees and the northerly and southerly alignment of nenzel ore bodies might lend weight to a theory of fracturing of uniformity in texture and mineralogical composition is significant ore specimens reveal so frequently original through the veil of secondary silica that the idea of having followed lines of high feldspar content is suggested the prevailing westerly dip of approximately 60 degrees and the northerly and southerly alignment of nenzel ore bodies might lend weight to a theory of fracturing that determined the position of these ore bodies the evidence of replacement is so convincing that the idea of fracture fill ing suffers although it may later be proven an important contributory cause proof is not at hand that is a condition necessary to nenzel hill hil ore the statement may be made however that ores mined to date have been found to be a rhyolite it is also noteworthy that only certain portions of the zone of are productive of ore this inference points to the enrichment having been subsequent to parallel droppings crop pings of silver ore on nenzel hill together with the regularity of dip to the fhe present depth of workings suggests that nenzel hill is rock ribbed in riches later developments show that gold is appearing in greater quantity on the lower levels prospecting is under way by several companies owning ground on the lower slopes of nenzel hill and the reward rev ard of their work has with few exceptions been quick and decided gold content is increasing most encouragingly encouraging ly as depth is attained an illustration of this is afforded on the limerick property situated one half mile I 1 no north rth of nenzel peak on a saddle several hundred feet hertica ver vertically tica ly lower here values are almost exclusively gold old mining alining activity around nenzel hill has created a healthy tone of optimism lincoln hill comes before the mining world in blinding blindin flashes new strikes of specimen rock are frequently encountered and afford a favorable field for the more daring of mining investors the geology of linco lincoln n hill presents problems of intense interest accessory minerals of primary origin are conspicuous and plentiful T much information that nay may i contribute to the systematic development of the district may be expected when lincoln hill will have received tho the attention it invites 01 |