BULL. GEOL. SOC. AM 



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VOL. 23, 1911, PL. 37 



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PRELIMINARY MAP OF PLEISTOCENE DEPOSITS OF PORTIONS OF GLACIER NATIONAL PARK AND BLACKFOOT 



INDIAN RESERVATION, MONTANA 

 (By Wm. C. Aldeii, assisted by J, E. Thomas) 



P2E 



Iliyli mouutaiu area dissected by many deep glaciated valleys, with small existing 



glaciers. 



Deposits of mountain .ulaciers of Wisconsin stage in valleys and on the plain east of 

 the mountain front (mapping not complete). 



Deposits of the Keewatin ice-sheet of the Wisconsin stage of glaciation. 



Deposits of pre-Wisconsin glacial drift capping high flat-topped ridges of Cretaceous 

 shale and sandstone — that is, lying on remnants of the Blackfoot peneplain (mapping 

 not complete). 



(Boundaries of drift of Saint Mary and Keewatin glaciers from F. H. H. Calhoun 

 and E. Stebinger.) 



