

BETWEEN NORTH BLOOMFIELD AND EUREKA 



401 



which can be supposed to belong to the old channel, whose course I have been following in these 

 notes, it will be convenient to put here in tabular form a summary of what has been already written 

 in regard to the question of grade of bed-rock. In regard to a supposed continuation of the old 

 channel towards the north more will be said when the description of the Forest City divide is 

 reached. The tabular statement is given below. 



Distance from 

 preceding Station. 



Totn I 

 Distance. 



Altitude, 



Differences of 



Altitude. 



Timbuctoo 

 Mooney Flat 

 Erencb. Corral 

 North San Juan 

 Badger Hill 

 Malakoff 

 Derbec Shaft 

 Watt Shaft 

 Snow Point 



2j miles 

 9 



6 



2 

 3 



4 



2J miles 



a 



ii 



tt 

 a 



it 



a 



a 



HI 



18 

 22£ 



29| 



31| 



34| 



38 i 



u 



it 

 it 

 it 

 ii 



it 



473 feet 



757 " 

 1,579 

 2,033 



2,391 

 2,929 

 3,353 



3,800 

 4,211 



a 

 a 

 it 

 u 

 a 

 u 

 it 



284 feet 

 822 

 454 

 356 



538 

 424 



447 

 411 



ii 

 it 



a 



u 

 it 

 it 



u 



Grade pox mile 



between 

 each Station 



and the 

 one preceding. 



114 feet 

 91 " 



ti 



u 

 u 

 u 

 a 



a 



67 



80 



72 



212 



149 



103 



g 



The average grade for thirty-eight miles and three quarters » ninety-six feet *° the mile. The 

 most noticeable 'deviation from the average grade is between Boomheld and the Watt Shaft. 

 Until further explorations are made no final explanation of this deviation can be reached. For 

 the present I am inclined to the opinion that there will be found somewhere between Bloomfield 

 and the Derbec Shaft, if work is ever so far prosecuted as to .nakc ,u, underground connection 

 between the two places, either a fault in the strata, formed subsequently to the deposition o the 

 .ravel, or else evidence of the former existence of cascades or rapids. Has opinion is based 

 entirely upon the steepness of the grade at this point, and cannot be, so far ae I know, corroborated 

 by anything now observable in the rocks. This point will he referred to again in connection with 



the altitude of Relief Hill. ... .. 1 ,. , 



The bed-rock seen at Woolsey Flat is an easily cleavable slate, whose dip is usually nearly vertical, 

 though in some places at an angle as low as from sixty to seventy degrees At Moore s Flat the bed- 

 rock is also slate, as it probably is at Orleans Flat. The last-mentioned place I did not visit he 

 s round was worked out many years ago. In the second report of J. Ross Browne, dated m 1868, the 

 diggings at Orleans Flat are spoken of as having been abandoned for several years The bed-rock 

 at the Shanghai diggings, which arc on the northwesterly extremity of Snow Point, « a very soft, 

 easily worked slate, which weathers very rapidly upon exposure to the air to a bluish or reddish 

 clay, or else has suffered decomposition to a considerable depth while stdl covered with gravel. 

 About five acres of bed-rock are uncovered at this point, and nearly the same amount on the 

 northern slope of the hill. I made no attempt to examine this second exposure of bed-rock, lor 

 the reason that the diggings have not been worked for several years, and the slides of clay and sand 

 have hidden a great part of the rock from view. I was told, however, that a few hundredfeet 

 to the east of the Shanghai diggings the bed-rock was a very hard slate, -the hardest land. 



The precise position of the deep channel between Snow Point and the Boston mine cannot be 

 given. The Snow Point gravel appears to have its longest axis in an easterly direction and there 

 are some indications of a rim on the northern side of the Shanghai diggings ; but the pitch to no 

 south is very gradual, and there is nothing to be seen above Snow Point to lead to the oeliel l.a 

 any old stream ever came down from an easterly or northeasterly directum. .1 ho M.oores am 

 bed-rock at my point of observation seemed to bo nearly level ; there was no well-dennea run o 

 be seen. As before stated, this point was on the northeast side of the grayel de port j, opposite 

 Orleans Flat. The gravel had been removed for a distance of from 800 to 1,000 feet back from 

 the ravine, where work had to be suspended on account of the tunnels being « °™ * P" 1 * "* 

 general course of the old channel from Moore's Flat to. Woolsey Flat is about S. 20 W. (magnetic;, 

 but at the Boston mine it is S. 25° E. (magnetic), the deflection towards the south amounting to 





