H. Wood — Cretaceous of Northwestern Montana. 403 



showing the glacial path as 40° north of west. These gravel 

 deposits, consisting largely of greenish and greenish-black 

 amygdaloidal traps, have a thickness of one hundred to one hun- 

 dred and fifty feet on the upturned edges of the Cretaceous 

 rocks, their lower portions being formed into beds of calca- 

 reously cemented sandstones and conglomerates. The origin 

 of the amygdaloidal trap bowlders is no doubt in the interca- 

 lated eruptive rocks of the Cambrian and Cretaceous at the 

 north and south Kootanie passes.* All the valleys of this 

 portion of Montana have a southerly or southeasterly direction 

 exhibiting evidences of glaciation as bowlder clays, lakes 

 behind terminal moraines, and rounded hummocky remnants 

 of ranges, in some cases extending for 150 miles from the 

 boundary or those higher altitudes which existed during or at 

 the close of a supposed epirogenic movement, f The range 

 flanking the valley on the south has a course a little northwest 

 with numerous transverse valleys, and corresponds with the 

 lower Cambrian Quartzitic series or Bow River series, as noted 

 by McConnell4 It dips east-northeast under the upturned 

 coal-bearing Cretaceous rocks. The Cambrian here consists of 

 heavily bedded red quartzites changing to sandstones alter- 

 nating with thinly bedded dark red argillaceous shales, and 

 lower in the series with greenish quartzites of ribbanded char- 

 acter, the upper portion of the series immediately underlying 

 the Cretaceous consisting of greenish gray quartzose slates. 

 The total thickness of this lower Cambrian, i. e., all that below 

 the dolomitic limestone and shales, as given by Dawson§ is 

 11,000 feet; by McConnell|| and Walcottl" 10^000 feet— the 

 latter of whom has recorded his results from the Gallatin sec- 

 tion, eastern Montana. A rough traverse made here along 

 Coal Creek gave me 2|- miles of upturned Cambrian rocks. 

 The total thickness of the series as given by Dawson is 29,000 

 feet. 



A search was made for fossils but none were obtained, nor 

 does it appear that any were found in this series in southern 

 British Columbia. The dip of the red quartzites is 25° E.N.E., 

 while the dip of the gray quartzose slates immediately under 

 the Cretaceous is 35° to 40° E.N.E., with a strike 20° north of 

 west. Evidences of shore lines were observed in the shape of 

 ripple marks, but no conglomerates or intercalated contempo- 

 raneous trappean rocks. The direction of this range is nearly 



*G. M. Dawson: Report 1886, pp. 46, 47, 57. 



\ Opham : Class, of Mount. Ranges. 



% McConnell: Rep. 1S87, C. a. S., p. 29. 



S Dawson: Rep. 1886, C. G. S., p. 51. 



|| McConnell : Rep. 1887, C. G. S., p. 29. 



■[[ Walcott : Correlation papers Camb. G. Survey. U. S. 



