

QUINCY AND VICINITY. 



H?K 



477 



The gold occurs principally oil the bed-rock, the top gravel being poor. That which conies directly 

 from the gravel is coarse ; the gold of the underlying ledge is finer. The average fineness of the 

 Mumford Hill gold is .945. Since the deposition of this gravel there has been a fault or a slip 

 in the bed-rock amounting to at least six feet. The fault is traced up through the gravel by 

 means of a clayey slickensides, the face of which is smooth and striated with parallel lines. It 

 was not easy to secure specimens which would show these markings, and at the same time be firm 

 enough to bear transportation. That this really marks the place of a crevice in the gravel is 

 further shown by the presence of rootlets of trees to a depth of twenty-five feet below the surface 

 of the ground, — a depth several times greater than that to which these rootlets make their way in 

 the undisturbed gravel. The strike of the fault or slip corresponds very closely with that of the 



bed-rock. 



From Mr. Edman I obtained a small quantity of concentrated sands from Rock Island, a gravel 



deposit the precise position of which I cannot give. These sands have been examined micro- 

 scopically by Mr. Wadsworth, who says of them : " The white crystals here are zircons, the majority 

 having the form figured in Dana's System of Mineralogy, page 273, except that the crystals are 

 longer and the prismatic planes correspondingly developed. Magnetic iron is abundant. Some 

 pale greenish fragments occur, which may possibly be broken augites. A grain or two of rutile 



V 



was seen. 



Between Mumford's Hill and the toll-gate on the stage-road from Quincy to Oroville the trail 



crosses Eagle Gulch and Deadwood Gulch. Between these two gulches lies Scad Point, "scad" 

 being in miner's parlance the equivalent of nugget. The Scad Point gravel is about a third of a 



mil 



e nor 



■th of Mumford's Hill, but is nearly 200 feet lower, the altitude of its bed-rock being only 



4 510 feet. It is evidently more recent in origin than the gravel of Mumford's Hill, for it contains, 

 together with a little quartz and some clay, a large proportion of volcanic material and representa- 

 tives of the country rock which is found in places in the near vicinity. The bed-rock has been 

 designated as a " greenstone porphyry," and forms part of a belt of similar rock, which can be 

 traced for several miles in a northwesterly direction. The grade of the channel is from east to 

 west, or directly towards the high escarpment of Spanish Peak, The thickness of the gravel is, 

 on the average, nearly fifty feet. The gold is said to be distributed through the whole mass. In 

 the beds of Eade Gulch and Deadwood Gulch geld used to be found as far up as their intersec- 

 tion with the two gravel deposits last described ; higher up, the gulches were poor or barren. On 

 the toll-gate ridge as I was informed by Mr. Ed man, there is a small gravel deposit, supposed to 

 be on the continuation of the Scad Point channel, in which further evidence of faultings of the 

 country rock, since the formation of the gravel, may be found. I did not visit the locality. 



The country, for five or six miles along the eastern base of Spanish Peak, between the stage-road 

 and Chaparral Hill, is said to contain several gravel deposits, of greater or less extent and of doubt- 

 ful date and uncertain origin. It is a district of which, on account of the abundance of vegetation 

 and the infrequency of good exposures of rock, but little can be learned in a hasty trip of a few 

 hours. I went as far as Tucker's Ranch, at the head of Scalos's Gulch, where the altitude is 4,100 

 feet. Near this point, according to Mr. Tucker's statement, there are two old channels, running in 

 different directions. A third channel, at an altitude several hundred feet higher, is supposed to 

 exist near the base of Spanish Peak. Further evidence of faulted bed-rock is reported from a 

 tunnel in Scales's Gulch. These interesting points had to be left without further examination on 



account of lack of time. 



The lower portions of this district, about Meadow Valley and Spanish Eanch, are covered, over 

 hundreds of acres, with gravid to an unknown depth. The low grade of Spanish Creek prevents 

 the application of the hydraulic process in the mining of these gravels, and the accumulation of 

 water in the workings would probably make shaft-sinking and drift-mining unprofitable. 



From the previous descriptions it can be easily seen that the gravel problem in the vicinity of 

 Quincy is not the same as it is in the country south of the Feather River. Irregularity takes the 

 place of a comparative uniformity ; a much-broken, faulted, and disturbed bed-rock, the place of 





