THE LATE PALEOZOIC IN BRITISH COLUMBIA 175 



Cache Creek formation, and the most definite feature which can be traced through- 

 out is the belt of massive * * * and whitish Hmestones, sometimes marbles. * * * 



"Practically the entire mass of the Marble Mountain Range is composed of 

 these limestones, as well as the whole eastern part of the Pavilion Mountains. 

 They include comparatively insignificant intercalations of argillite, cherty quartz- 

 ite, and materials of volcanic origin. Farther south, in the region to the east of 

 Hat Creek, such materials become more abundant and form thick beds among the 

 limestones, particularly the cherty quartzites and the greenstones. In this region 

 it is probable that the lower part of the great limestone series is most prominently 

 displayed and that the higher beds are more characteristic in the north, particu- 

 larly in the Marble and Pavilion Mountains. The earlier stages of the great 

 period of limestone deposition appear to have been marked by frequent interrup- 

 tions, during which argillaceous and volcanic products were laid down; while 

 in its later stages the deposition of the limestone must have been almost unbroken. 

 The interlocking of the different classes of materials is such, however, as to show 

 the close connection which obtains between the Marble Canyon limestones and 

 the lower parts of the Cache Creek formation. * * * 



"The extremely unsatisfactory condition of the rocks of the Cache Creek 

 series for all purposes of measurement [is such that] in endeavoring to give some 

 idea of the total volume of the formation, no even approximately correct data 

 can be quoted. The subjoined summarized section is therefore merely an attempt 

 to indicate the general order of succession, and to some extent the importance 

 of the formation, in the western part of the area of the [Kamloops] map. The 

 order is descending. 



Feet 



1. Massive limestones (Marble Canyon limestone), with some minor intercalations of volcanic rocks, 



argillites, and cherty quartzites. At least 1,000 feet seen in some single exposures. Total 

 thickness probably at least 3,000 



2. Volcanic materials and limestones, with some argillites, cherty quartzites, etc. Minimum thick- 



ness about 2,000 



3. Cherty quartzites, argillites, volcanic materials, and serpentines, with some limestone. The 



thickness of these beds, or of a part of them, was roughly estimated in two places as between 

 4,000 and 5,000 feet. Minimum total thickness, say 4,500 



9>500 



"Thus, the entire volume of the rocks of the Cache Creek formation, as this 

 is now defined, may be assumed to be about 10,000 feet as a minimum, while I 

 am inclined to believe that it really exceeds 15,000 feet. 



"A few characteristic fossils have been obtained in a number of places beyond 

 the limits of the present map. At Stuart Lake (latitude 54° 30'), Dease River 

 (latitude 59° 15'), Frances River (latitude 60° 30'), and on Tagish Lake (latitude 

 60°), fusuline limestones have been observed. 



"To the westward of the Coast Ranges (in which it is probable that numerous 

 infolds of Paleozoic rocks will yet be found) a formation known from its fossils 

 to be of Carboniferous age is again well represented. This has, so far, not been 

 very minutely examined or reported in detail, but it is known to comprise thick 

 beds of limestones, argillites, and volcanic materials, the latter being even more 

 characteristic and in greater development than in the region here specially dealt 

 with. 



"In the Rocky Mountains proper, or eastern member of the Cordilleran sys- 

 tem, the section which must now be regarded as the typical one for these latitudes 

 is that worked out by Mr. R. G. McConnell. In this section the Carboniferous 



