WIXONA COUNTY. 253 



Jordan sandstone.] 



west road east of the center of section 23, Utica. In these cases it is a firm, 

 evenly stratified rock, which affords angular blocks for abutments and walls, 

 and at the railroad exhibits a thickness of twenty-five feet. On section 18, 

 Warren, the bottom of the Shakopee overlying is also exposed at points m 

 the highway a little further south in the high land. The strata of the 

 Jordan are from three to four inches, as exposed, but it shows by its rustiness 

 that it is shattered by long weathering. It is broken into square blocks in 

 situ, which fall out by the action of the frost. A resident farmer has enclosed 

 some of his land by a handsome stone wall, evenly laid up with blocks of 

 this stone, some of the pieces being one foot in thickness. In a similar way 

 this rock appears along the road between sections 2 and 3, St. Charles, near 

 the top of the hill at the crossing of the South Whitewater river. 



The Jordan is also seen in the bluffs at Troy, where it has an exposed 

 thickness of eight feet. It is probably present where the large sink-hole 

 occurs in the road about two miles west of Lewiston, and at one mile south 

 of Utica. 



The Jordan is white and siliceous, similar in that respect to the St. 

 Peter, when not long weathered. It is for that reason liable to be mistaken 

 for the St. Peter. But in many places it has been observed to differ from 

 that formation in being firmly and conspicuously stratified, affording dura- 

 ble angular blocks that long resist the weather, and are carried by freshet 

 waters down the ravines with masses of the more durable parts of the lime- 

 stones. The St. Peter is much less cemented, and in Minnesota has never 

 been known to furnish such blocks. 



The St. Lawrence limestone. This formation which, including with some 

 indistinctness the overlying Jordan and Shakopee, Dr. Owen designated 

 Lower Magnesian limestone, is still frequently known by that name. It 

 occupies the summits of the bluffs of the Mississippi and its tributaries 

 throughout nearly the whole county, having a thickness ot about 160 feet. 

 An unfavorable measurement was made of this limestone in Houston county, 

 which seemed to give it a thickness of about 200 feet, but from numerous 

 measurements made in Winona county it is certainly somewhat less than 

 that in this county. This may be in part due to the anticlinal position in 

 which it is found, making it more susceptible to denuding agencies. 



There are two distinct members that prevail in the St. Lawrence lime- 



