i6 



Miles and Beyond White River for 20 miles (\2-2 km.) 



is a granitic region, largely covered with sand, 

 beyond which the Keewatin again appears 

 and continues with slight interruptions to 

 Peninsula, where the remarkable series of 

 laurvikite, syenites and nepheline syenites of 

 the Port Coldwell region begin. From this 

 point the scenery changes from the diversified 

 cliffs on the north and the broad expanse of 

 Lake Superior to the south. 

 382 m. Coldwell — Several short tunnels cut 



615 km. through buttress-like projec- 



tions of the rock masses. The nepheline syenite 

 series extends from near Peninsula to Middle- 

 ton. 



THE NEPHELINE AND ALKALI SYENITES OF THE 

 PORT COLDWELL AREA. 



BY 



A. E. Barlow.* 

 INTRODUCTION. 



Location and Size of Area. 



The Port Coldwell area of nepheline and alkali-syenites 

 is situated on the northeast side of Lake Superior, extending 

 from a point on the Canadian Pacific Railway nearly two 

 miles (3-2 km) east of Peninsula station to another point 

 on the same railway a short distance west of Middleton 

 The area underlain by these rocks, including the shore line 

 and off lying islands, is a little over 15 miles (24 km) from 

 east to west. The necessary curves, in following the sinuo- 

 sities of the coast line of the lake, have increased the distan- 

 ce along the railway to about 2 1 miles (33 • 7 km) . Its north- 

 ern boundary is believed never to be more than 10 miles 

 (16 km.) from the shore or railway. The total area under- 

 lain by these rocks is probably about 100 square miles (259 

 sq. km.) 



* Synopsis of paper by H. L. Kerr, Toronto, Canada. 



