2 KIK J. W. DAWSON OX THE MESOZOIC FLORAS OF 



uous class. Still higher in the series, the strata abound iu Dicotyledonous leaves, closely 

 allied to those of the Dakota series of the United States p;eolog-ists. 



It is proposed to name the older series the Kootanie Series, after a tribe of Indians who 

 hunted in the coimtry in AA'hich it occurs. The upper series may be named, after a typi- 

 cal locality, the Mill Creek Series, and the plants occurring between these two horizons 

 may be termed for the present those of the Intermediate Series. There is good reason 

 to believe that the Mill Creek series is somewhat older than that named in my former 

 paper the Dunvegan groiip of Peace River. 



Dr. Gr. M. Dawson has furnished the following notes as to what is known of the 

 stratigraphy and distribution of these several groups of strata : — • 



" "Where the Rocky Mountains are intersected by the forty-ninth parallel they form a 

 compact range, entirely composed of Palreojcoic rocks, from their base at the eastern foot- 

 hills to the great Kootanie-Columbia valley on the west.' About thirty miles further 

 north, however, important masses of Lower Cretaceous or Jurasso-Cretaceous rocks become 

 involved in the flexures of the older series, upon which they rest with more or less angu- 

 lar unconformity. These rocks also hold, at several stages, conglomerates composed of the 

 underlying series which probably stood out in insular masses in many places. The Creta- 

 ceous rocks generally appear to occupy synclinals, which are either simple and narrow, or 

 scA'eral miles in width, and hold a number of parallel, more or less closely compressed, 

 folds, which in several cases have been observed to be overturned to the east or north- 

 east. Similar sharp parallel folding occurs in the foot-hill country, which forms a belt 

 along the eastern base of the range ; and though, owing to the amount of disturbances, it 

 has hitherto been found impossible to work out the structure in detail, it is probable that 

 sections will ultimately be obtained embracing the entire thickness of the Cretaceous for- 

 mation, together with a portion of the Laramie. In the region of the great plains, north 

 of the forty-ninth parallel, none of the Cretaceous rocks yet known can be assigned to a 

 position lower than that of the Benton group, and to the south and south-east, in the 

 western states and territories, the basal beds of the Cretaceous, whereA'er exposed, are of 

 the age of the Dakota group. In connection with the folding above described, however, 

 while some beds probably referable to the Dakota period have been recognized by their 

 fossils, there is eAndence of the existence of a much earlier stage of the Cretaceous, which 

 it is proposed to designate locally as the Kootanie series. These rocks consist largely of 

 sandstones, interbedded with shales and shaly sandstones, and including occasional beds 

 of conglomerate ; and a zone containing coal seams, which are sometimes of considerable 

 thickness, is represented at a number of different localities. While it is evident on strati- 

 graphical grounds that the position of these beds is far down in the thick series of Creta- 

 ceous rocks here represented, no fossils have yet been obtained from them saA*e the plants 

 described in this paper, and on these alone their reference to any particular horizon in the 

 Cretaceous must rest. 



" The localities from which plants of this stage haA^e already been collected are scat- 

 tered OA^er a considerable area north of the forty-ninth parallel and south of Boaa^ 

 River, the length of Avhich may be stated as about 140 miles, with an extreme breadth of 



' There are, it is triio, in several places, comparatively siii.all areas of red rock.s, believed to bo Triassic, but 

 f.Jipse are conformable with the Devonio-Carboniferous limestone series benouth. 



