136 GEOLOGICAL SURVEY OF THE TEREITORIES. 



much metamorpliism and obliteration of bedding has here naturally 

 taken place, yet there is enough structure remaining to show that the 

 legs of the V make an angle of only about 70° degrees with on^j another. 

 The erosion of the surrounding rock has left the south end of this Y- 

 shaped mass almost as if perched upon a pedestal of granite. The main 

 ridge, however, continues on past the deep cut of the South Boulder 

 almost to Coal Creek, but gradually disappearing beneath the soil. 



Abreast of Bear Caiion, about three miles to the east, the outer series 

 of rocks, as the liguitic with the coal horizons, all have a gentle eastern 

 dip, but in coming southward of Coal Creek they approach the mount- 

 ains and assume a nearly vertical position. Just south of Coal Creek 

 Caiion section 12 occurs, (Plate II, as usual, and Fig. 4,) in which some 

 of the red-beds lean beyond the vertical, and appear as an eastern wall 

 to the little valley inclosed between them and the hills of schist and 

 granite upon the west. To the east they rapidly flatten, while within a 

 half mile to the south the same beds, rising in a higher ridge upon the 

 archtean rocks near Ealston Creek, again show a flat dip. Within ex- 

 ceedingly short distances, then, great changes of dip may occur, and 

 from them, with but slight changes of exposure, unconformability might 

 be inferred. Yet all are perfectly conformable ; the sudden change 

 really indicating only a very abrupt flexure in the main fold, as indicated 

 by the dotted lines. To the east the formation again steepens, the coal 

 horizons being found nearly vertical, while still east the higher beds 

 again quite suddenly assume a flatter position, indicating just such 

 another abrupt flexure as occurs here nearer the mountains, but not 

 necessarily any more of an unconformability than here. 



A few miles north of Golden City (see Fig. 4) a very remarkable con- 

 traction of tlie whole series commences, all the outer ridges bending 

 rapidly westward to form a sort of loop or bay in the rear of the Table 

 Mountains, and near the narrowest point of which Golden City is situated. 

 There has been some diflering opinions ex^jressed about the structure of 

 this region, and a section here is one of the most important of the series. 

 In absence of a complete or personal examination, a section drawii by 

 permission from one made by Mr. E. L, Berthoud, is presented, (ISTo. 

 13.) Its general correctness may be assumed not only on account of the 

 opportunities and ability of Mr. Berthoud, but from the evidence aiforded 

 by the adjoining sections, between which and that at Golden there are 

 many points in common. 



The close proximity of the vertical coal-beds to the horizontal beds of 

 Table Mountain has been taken as indicating unconformability between 

 the two, though in reality it no more follows from this fact than would 

 unconformability in the Triassic from the similar phenomenon presented 

 near Coal Creek. Indeed, the change of dij:) here is hardly as abrupt as at 

 the latter j)oint. An abrupt fold, as indicated in the other sections 

 along the front 6f the range, with erosion removing those portions which 

 by fracture, &c., are most likely to be removed, would naturallj^ leave 

 this portion of the section as it now appears, the lignitic being continu- 

 ous and conformable throughout. 



One of the most interesting features presented in the Golden section 

 is the apparent thinness of the usual lower beds of the series. This 

 may be caused by an actual thinning of the original deposits at this 

 point, or by a fault which has pushed the higher portion of the series 

 westward over the upturned edges of the lower portion, thus concealing 

 much of the latter. That the former is not impossible follows from the 

 conditions naturally attending the laying down of new formations upon 

 the newly-prepared, and beace uneven, surfaces of older rocks, and 



