KICK COUNTY. 



Shnkopce limestone.] 



nr>w by the cementation of the sand-grains about their exterior, or by a looseness of the same in 

 their interior, thus not only forming a rude cast of each stem within the rock but also providing 

 for the more rapid erosion and removal of the grains that may have reached within their cases. 

 The spots are only seen on upper surfaces, and if they be not due to imprisoned rushes or stems 

 of some sort, or to worm- burro wing, they are at present inexplicable. They are generally from an 

 eighth to a quarter of an inch in dialneter. 



The Cannon river enters on the Shakopee, having cut through the St. Peter, in sec. 4, Cannon 

 City. This sandstone is also abundantly exposed in the valley of Prairie creek, in a great many 

 places. In the eastern part of Northlield it constitutes the isolated mound-like hills that rise 

 above the lower prairie to the upland, marking the limit of the overlying Trenton limestone. The 

 outrunning edge of the St. Peter sandstone is not visible in the drift-covered westef n portion of 

 the county, its most westerly exposures being a perpendicular bluff in the west bank of Heath creek, 

 S. E. } sec. 34, P.ridgewater, and an isolated mound facing the river on the S. E. } sec. 26, Wells. 

 This sandstone undoubtedly exists in considerable areas in that portion of Rice county, extending 

 through Le Sueur county to the Minnesota valley, but with these exceptions not a single exposure 

 of it has been recorded. In Wheatland and Webster it is also highly probable that the Trenton 

 limestone caps the St. Peter sandstone in some of the hills that diversify those townships, since it 

 is known to occur in such hills a few miles farther north in Dakota county, but as this is wholly 

 conjectural, the plate of the county represents only drift in those townships. 



The Shakopee, limestone. This formation is exhibited at Northfielcl. It 

 affords a thickness of about thirty-five feet in Rice county, its chief outcrops 

 being in the Cannon valley between Dundas and the Dakota county line. 

 At Dundas the depot of the Chicago, Milwaukee and St. Paul railway is 

 twenty-two feet above the top of the Shakopee, and the Cannon Valley 

 depot is about level with its upper surface. At the north county line the 

 Iowa and Minnesota division of the Chicago, Milwaukee and St. Paul rail- 

 way is ten feet above the top of the Shakopee, and at Northfield it is fifteen 

 feet lower than its upper surface. A the county line the Cannon Valley 

 railway is twenty-five feet below the top of the Shakopee and at Northfield 

 it is about twenty feet. This formation is that which underlies immedi- 

 ately the drift in most of that part of the county west of the Cannon valley, 

 but no outcrops of it are known there. At Northfield it is seen in the 

 streets of the city, and is excavated for cellars and foundations for buildings. 

 It is frequently seen along the "river road" below Northfield on the west 

 side of the river, where it has been wrought for quicklime. 



The lithology of the Shakopee at Northfield is variable, resembling that seen at its typical 

 and original locality. The limestone is impure, and passes to a shaly magnesian rock. Some of 

 it is in beds of three or of two inches, and some is coarse and vesicular, and in heavy beds. In 

 the midst of the limestone are layers of white sand from three to six inches in thickness, two of 

 them embraced in the interval of fifteen feet. One of these pinches out entirely in a distance of 

 twenty feet, letting the limerock above lie on that below, and the other becomes mingled with 

 lumps and lenticular masses of green shale. In other places, as at Tramm's limekiln, some of the 

 limestone layers embrace, along with rounded grains of quartz sand, some pieces of, apparently, 

 weathered chert, and indistinct remains of molluscs, probably of the same species as seen in the 

 Shakopee at Cannon Falls, in Goodhue county. 



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