EXPLANATION OF PLATES 375 



Explanation of Plates 



Plate 29. — Map of Central-Eastern Minnesota 



On this map are represented all the rock exposures known. The conventional 

 expresses the type of rock. The northern part of the map is probably Animikie ; 

 it is generally believed to be underlain by tlie southward stretching beds of the 

 Mesabi iron range. The southeastward border is determined by the exposures of 

 several localities and the deep well at Dalbo. The fault line defines the northwest- 

 ward limits of the Keweenawan of eastern Minnesota. Topography from maps of 

 Geological Survey of Minnesota. 



Plate 30. — Profiles across the Keewatin of Eastern Minnesota 



I. — Profile from the Giants range to Wrenshall. 



This is a general section of the Mesabi Iron range (after J. E. 

 Spurr), and the clastic series from Stony brook to Wrenshall. 

 To the south of the Mesabi lies the series of more or less folded 

 graywackes and associated rocks north and south through Clo- 

 quet and Carlton, where the rocks are in almost continuous 

 exposure. 



II, — Profile from Duluth to Saint Cloud. 



The rocks are in exposure at all points named on the profile. A 

 small area of Cambrian sandstone lies between the Snake River 

 and Ann River crystallines. 



III. — Profile from Cloquet to Hinckley along the Kettle river. 



Beginning west of Cloquet the profile passes through the quarry- 

 town of Sandstone to sections 22-23, township 41, range 20, 

 where the great Keweenawan fault line lies. The Cambrian 

 completely covers the underlying Algonkian rocks from Rut- 

 ledge southwards. 



IV. — Profile from Aitkin to Chengwatana. 



The glacial Lake Aitkin clays are assumed to overlie the westward 

 extension of the Mesabi, since to the southeast of Aitkin quartz- 

 ite has been discovered. Cambrian sandstones exposed on the 

 Snake river and penetrated to 700 feet at Pine City near Cheng- 

 watana are assumed to be continuous between these points. 



v.— Profile from Little Falls to Taylors Falls. 



To the east of Dalbo this profile passes outside the area mapped. 



All of these profiles are partly generalized; 



LIII— BuT.T,. Geou Soc. Am., Vot,. 12, 1900 



