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PROCEEDINGS OE THE GEOLOGICAL SOCIETY. 



[Apr. 10, 



3. Calcareous marl, Ostrea congesta, Inoceramus prohlematicus, 



1. Sandstone and clay with fossil wood 90 feet. 



" The change from III. to IV. is always well marked. 



•' Inoceramus problematicus, which is the same as I.fragilis, is the characteristic 

 fossil of Nos. II. and III., and with Ostrea congesta ranges to Mexico. 



" These latter groups everywhere rest on the sandstone and clay beds (No. I.), 

 which are the ' Jurassic ' of M. Marcou. 



"With the exception of two species, the Cretaceous fossils of the Mexican 

 frontier are distinct from those of the New Jersey section, and nearly equally so 

 from those of Nebrasca ; whereas the latter or Nebrasca section, extending from 

 the Missouri westwards, has many fossils in common with those of New Jersey 

 and Alabama. It is therefore probable that the Mexican beds represent a 

 different epoch in the Cretaceous series from those of the east and north-west. 

 However, from the Mexican frontier no sections were obtained to show whether 

 one or more groups were represented." — Rep. Mex. Boundary-commission, 

 vol. i. p. 126.] 



Group F. — In speaking of the Tertiaries, I have mentioned the 

 only places where it is probable that the route of the Expedition 

 touched on the strata of this group — viz. at the height of land of the 

 Qu'appelle River and at La Roche Percee, where the lower sandstones 

 may perhaps be of this age. 



Grotop E. — By reference to the map, it will be seen that the first 

 point where the route of the Expedition passed over Cretaceous strata, 

 was after gaining the great plain of which Pembina Mount forms the 

 eastern limit, at Long River, latitude 49° 8' N., longitude 9S° 35' "W., 

 which is a tributary of Pembina River, flowing northwards. This 

 stream flows through a deep valley in the high plateau stretching 

 back from Pembina Mount, and in its gulleys are exposed sections 

 of group B. It is a compact shale of light greenish- drab colour, not 

 occurring in continuous layers, but as fragments with irregular 

 conchoidal surfaces, which have been produced by the desiccation of 

 what were originally thin layers of clay. Sometimes it has more of 

 a slaty character. Among these beds are hard bands and nodular 

 masses of dark-brown clay-ironstone, and perpendicular fissures are 

 common, which are filled up with splintery iron-shale. Also small 

 coloured tubes traverse the strata perpendicularly in large numbers. 



The same strata were observed at Forked Creek, where a deep 

 gulley joins the valley of the Assineboine in latitude 50° 6' N., and 

 longitude 101° 18' W., and these two places are both on a line of 

 high hilly ground, which stretches in a north-west direction, no 

 doubt marking the outcrop of the shales. At Long River they dip 

 gently to the south, and are covered by 6 feet of pure white sand, 

 very incoherent ; and over this lies the Drift, consisting of light-grey 

 calcareous earth. At Forked Creek they seemed to be strictly hori- 

 zontal, and were covered by a local drift derived from the subjacent 

 beds. Mr. Hind, who also saw the beds at Forked Creek and other 

 localities, submitted the fossils which he obtained to Messrs. Meek and 

 Harden ; and they have referred them to their second highest group. 

 He gives the following list as named by them* : — 



* Rep. Sask. Exploring Expedition, p. 180. 



