PLATE LXII. 



POLK AND NORMAN COUNTIES, 1899. J. E. TODD. 



Throughout the whole of this large area no outcrop of the bedrock is known, 

 but the topography and drift features present interesting characters. While in 

 general this region is covered by till, there are extensive tracts that are characterized 

 by modified drift. The largest of these are along the Red River of the North. A 

 fine laminated clay forms the soil over a belt that runs north and south, and is about 

 eighteen miles wide. This clay is thinner toward the east, and apparently fades out 

 gradually, allowing the till to form the soil. It extends further east up the valley 

 of the Red Lake river than elsewhere, and also forms a large patch at Red Lake falls. 

 This broad belt suffers an interruption, however, in northwestern Norman county, 

 where the till rises to the surface continuously from the main till area to the Red 

 river, forming a cross-belt about ten miles wide. This cross-belt of till is believed 

 to be due to morainic accumulation submerged for a long time by lake Agassiz. 

 Other patches of modified drift, due to the free action of water on the till in the act 

 of deposition, as explained by Mr. Upham, are found in the eastern part of the county, 

 one as a delta of Sand Hill river at the time of the formation of the Herman beach 

 of, lake Agassiz, and others as the result of local drainage from the glacier at the 

 time of the accumulation of the morainic drift. The belt of modified drift which 

 starts from the moraine in the north part of Lindsay, Polk county, running south- 

 westwardly to the south part of Winger, in the same county, coinciding there with 

 the valley of Sand Hill river, marks probably the course of a glacial stream along 

 the border of the glacier when it filled the Red River valley and extended eastward 

 to about that place. At a later date, as the ice withdrew beyond the Herman beach 

 at this latitude, the same stream, as interpreted by Mr. Todd, united with lake 

 Agassiz in the northwest quarter of the town of Lindsay, and was nearly cotem- 

 porary with the formation of the stony, narrow moraine, or kame, which is found in 

 sees. 31, 32 and 33, T. 150-40. 



Other ancient stream courses, probably having similar origin and slightly earlier 

 date, are those indicated by the narrow belts of modified drift, running from the 

 moraine, or across it, in the southeastern part of Norman county. 



Mr. Todd suggests a somewhat different succession of events for the glacial 

 history of these counties from that expressed by Mr. Upham, viz, he supposes the 

 glacier lingered longer in the valley of the Red River of the North than on the high- 

 lands of the " park region," and hence that there was a large interlobate area between 

 the Lake Superior ice-lobe and the Red River lobe, which was the scene of great 



