Vi CONTENTS. 



Chapter II. — Topography of the basin of Lake Agassiz — Continued. Page. 



Kivers tributary to Lake Agassiz anil draining its area 50 



Rainy and Winnipeg rivers 50 



Ked Lake River 52 



Red River 54 



Sheyenne River 56 



Langs Valley 57 



Pembina River 57 



Assiniboine River 58 



Qu'Appelle and Souris rivers .59 



Little Saskatchewan or Fairford River 61 



Saskatchewan River (il 



Smaller tributaries of Lake Winnipeg t)2 



Nelson River 62 



Extension of the basin of Lake Agassiz by glacial lakes outllowing to it from the region of 



the Peace and Athabasca rivers 63 



Chapter IIL — Geologic formations rNOERLYiNG the drift 65 



Archean formations 65 



The Archean area in Minnesota 66 



Vicinity of the Lake of the Woods, Rainy L.ake, and northward 67 



Boundary of the Archean toward the west 67 



Lower Silurian formations 68 



Outcrops on Lake Winnipeg 69 



East Selkirk 70 



Lower Fort Garry 71 



Stony Mountain 71 



Little Stony Mountain 71 



Stonewall 72 



Upper Silurian and Devonian formations 72 



Sections of artesian wells in Paleozoic strata 74 



Well at Humboldt, Minn 74 



Well at Grafton, N. Dak 77 



Well at Rosenfeld, Manitoba 78 



Well at Mordeii, Manitoba 81 



Cretaceous formations 81 



Marine sei ica of the Upper Missouri 81 



In the South Saskatchew.an basin 82 



Along the Manitoba escarpment ' 83 



The brackish- and fresh- water Laramie formation 84 



The western plains a lacustrine and land area since the early part of the L.aramio 



epoch 85 



Fort Pierre shales west of L.ake Agassiz 86 



Southwestern Minnesota and the Coteau des Prairies 86 



Along the Sheyenne River 91 



In the escarpment and plateau of Pembina Mountain 93 



In western Manitoba and Assinibola 97 



Former extent of Cretaceous beds eastward on the area of Lake Agassiz 100 



