*,*-, 



QUINCY AND VICINITY. 



473 



supposing an error on my part of one hundred feet in reading the barometer at Gopher Hill. The 

 distance from Shores Hill to Gopher Hill is about a mile and. a quarter. If the fall between the 

 two places is nearly two hundred and forty feet, the grade of the old channel was unusually high, 

 and, what is still more remarkable, in a direction just the reverse of that of Spanish Creek, though 

 conforming to the main drainage of the country, as illustrated in the forks of Feather River. 



Near the western end of Gopher Hill there are two strong pieces of evidence of extraordinary 

 disturbances since the deposition of the gravel. On Plate V are given two sketches as they were 

 made on the spot. At one place (Fig. 4) the bed-rock distinctly overhangs the gravel, the 

 projection amounting to about six feet at the point where I took my sketch. The arrangement of 

 the small boulders and flat pebbles in the gravel in the vicinity of this fault was peculiar, and led 

 to the belief that the limit was formed after the gravel was deposited. A few rods to the south of 

 the point just referred to the bed-rock is seen to fall off nearly vertically to the west (Fig. 5). 

 What the extent of this fault is, no one knows. In a well which was sunk in the gravel to the 

 west of the fault, to a depth of forty feet, no bed-rock was reached. From this point on in a 

 westerly direction, across and on the opposite side of Wapousa (or Waponseh) Creek, gravel is seen 

 at the surface, without much change of appearance, and but little above the level of Spanish Creek, 

 for the distance of a mile. Near the mouth of Wapousa Creek the southern rim of the channel is 

 seen between the gravel and Spanish Creek, pitching rapidly toward the north ; the northern rim 

 is seen in the form of high bed-rock, a quarter of a mile distant. Between Wapousa Creek and 

 Spanish Ranch the surface-gravel spreads out over a much wider area, as a low gravel ridge, from 

 a half-mile to a mile in width. The thickness of this gravel deposit has never been ascertained, 

 nor is it known precisely where the bed-rock rises again to the west. At Hepsiclam and Potosi I 

 traced the channels until they disappeared in the air; here I have run one into the ground. An 

 attempt to suggest an explanation for the facts above described is deferred until additional detail 

 in regard to these gravels, and others in the vicinity, have been given. 



The bed-rock, where exposed to view upon these hills, is slate. Upon Badger Hill I made the 

 strike of the slates to be N. 75° W*. (magnetic) ; the dip is nearly vertical. About a quarter of a 

 mile westerly from Wapousa Creek the easterly edge of the great serpentine belt is seen. This is 

 probably a continuation of the same belt that has previously been traced from Downieville, by way 

 of Deadwood and Whiskey Diggings, to Onion Valley. 



The gravel of these deposits is not clean white quartz, like that of La Porte and Howland Flat. 

 It is made up principally of pebbles of metamorphic or eruptive rock, flattened rather than spher- 

 ical, and small in size. There are hardly any pieces larger than a man can lift. At Badger Hill 

 I saw pebbles of volcanic rock, similar in character to that which caps some of the neighboring 



s 



,-1 



ridges, distributed through the gravel all the way down to bed-rock. The occurrence of these peb- 

 bles in this position is sufficient to prove the comparatively recent origin of the deposit. Owing to 

 the great irregularity of the bed-rock, — a fact which seems to indicate that the old channel was 

 not uniformly eroded over its whole width of 1,200 feet before the deposition of the gravel began, 

 it is hard to say what the average height of bank is. At different places on Badger Hill I esti- 

 mated the height and character of the bank as follows : Fifty feet of clean gravel ; twenty-five 

 feet of gravel covered with fifty feet of clay and sand ; one hundred feet of gravel and one hundred 

 feet of clay, with thin gravel-streaks near the top. Some of this irregularity may be due to the fact 

 that the southern parts of Badger Hill and Shores Hill have been cut away by Spanish Creek. 

 Upon Shores Hill there is said to be no pipe-clay, excepting here and there in small patches. No 

 petrified wood is found in these gravels. These deposits were worked as drift-mines as long ago 

 as 1854, and were regarded as very rich. The best gravel is found on and near the bed-rock ; but 

 all the coarse gravel, up to forty or fifty feet in thickness, carries gold in paying quantities. The 

 gold is, on the whole, coarser than that of Nevada County, though there is also considerable fine 

 gold. Occasionally a nugget of good size is found ; the largest one saved last year was worth 

 twenty dollars. The average fineness of the gold is .940, ranging from .925 for the coarse bottom 

 gold to .953 for the finest. The average yield per acre of hydraulic ground is stated to be $10,000. 



