WINONA COUNTY. 261 



Alluvial Terrace.] 



There is drift-gravel, and some stones at least eight inches in diameter, a mile and a half 

 south of Oak Ridge, by the road, section 5, Norton. 



On section 17, Norton, in the valley of the creek, is a boulder of white granite two and a half 

 feet through, the smaller diameter being about a foot and a half, associated with several smaller 

 drift stones, but in general at this place can be seen only the yellow loam. 



In the foot of the slope, near the head of Winona lake, are at least two large granite boulders, 

 one of them being rather dark and hornblendic and three feet across. These are so situated that 

 they may have come with the deposition of the material of the terrace, but they are too large to 

 have been brought by water ulone. There are also other, finer, drift-stones and gravel, along the 

 bluff road, which may be regarded the remains o f the great river-terrace which is found in the 

 protected angles of the bluffs at various places in Winona county. 



In the southern part of the county, as far west at least as Money creek, no drift can be seen, 

 except the pebbles along the Mississippi river. Along the valley of Money creek no drift is visible, 

 but on emerging from it to the uplands on section 29, Wilson, a few small foreign pebbles may be 

 seen in the gullies by the roadside. 



On section 10, Fremont, (N. W. J) are traces of drift in the form of stones and boulder, 

 The soil is also a sandy loam, sometimes a little gravelly. 



There are no foreign stones along the valley of Rush creek, nor in the washouts. 



In ascending Pine creek valley, in the southern part of Fremont, and thence west to Clyde 

 post office, no drift can be seen, but it probably lies intact on some of the upper swells of the sur- 

 face, under the loam. Indeed Mr. J. D. Clyde, section 18, Fremont, has a well which struck blue 

 stony clay under the loam, at a depth of ten feet. It i about fifteen feet thick, and has white 

 sand below it. He took out a "lap-stone" eight inches in diameter, from this well. Several other 

 wells in the same neighborhood have encountered the same blue clay. 



There is drift, even boulders of granite, at the corners of the towns of Saratoga, Utica, 

 St. Charles, and Fremont, seen in a ravine of the Trenton. 



At St. Charles, and a mile or two east of there, the drift under the loam appears thickened 

 obscuring the geological boundaries somewhat. It lies _bjth on the elevated land (above the 

 Trenton) and in the valleys, but is visible, particularly in the former position, or on the upper 

 part of the slope from the table-land. North and northeast of St. Charles there is much evidence 

 of a thicker deposit of drift under the loam than in the rest of the county, 



High alluvial terrace. In some places along the Mississippi river may 

 be seen a high alluvial terrace, preserved in the retreating angles of the 

 rock bluff. This plateau also ascends some of the valleys tributary to the 

 Mississippi, particularly the larger ones, and constitutes the principal fea- 

 ture of their topography. It also gives character to their agricultural 

 capabilities, spreading its arable soils high up the bluffs, which would other- 

 wise be precipitous and rocky or too sandy for tillage. The upper portion 

 of the contents of this terrace is frequently a loam undistinguishable from 

 that which everywhere covers the county, but the lower portion consists 

 of coarser sand, and often of gravel. 



At Beaver, in the valley of the Whitewater, there is a loam and gravel terrace that rises from 

 forty to fifty feet above the bottom-land, or flood-plain, though it is probably very rare that this 

 bottom-land is flooded by the river. 



The gravel terrace rises fifty-eight feet above the flood-plain of the Rollingstone, on section 

 10, near Minnesota City, and about sixteen feet above the level of the Minnesota City depot, or 

 fifty-two feet above the Mississippi river at low water stage. 



At Pickwick the loam-clay that constitutes the top of the terrace is stratified, as may be seen 

 also in numerous other places in the county ; but it is difficult to affirm this of the loam, in its 



