326 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



on Warren County/ It is a large mass of Clinton limestone, covering 

 about three-fourths of an acre and having a thickness of 16 feet. It is 

 found east of Little Miami River near Freeport, and is 2 to 3 miles out- 

 side the limits of the Wisconsin drift. It overlies Illinoian till and other 

 di-ift material. It was thought by Orton to have been derived from the 

 outcrops west of the river, but in the writer's opinion it was more probably 

 derived from the northeast. This opinion is based on the fact that the 

 striae at Wilmington, a few miles to the east, that underlie the Illinoian drift, 

 and are therefore connected with an ice movement as early as this bowlder 

 transportation, have a southwestward bearing. 



STRIDE. 



Observations of striae are not rare in the district covered by the Miami 

 lobe, there being thirty-three recorded within this district south of the 

 Wabash moraine. None have been observed outside the moraine under 

 discussion, but between this moraine and the next succeeding one there are 

 seventeen observations. Of these four are in Wayne County, Ind., and 

 bear west of south toward the western limb of the moraine; tliree are in 

 Butler County, Ohio, and bear southward toward the point of the morainic 

 loop; the remainder are in the district between the Grreat and Little Miami 

 rivers, and bear southeastward toward the eastern limb of the moraine. 

 The glaciation, therefore, harmonizes well with the distribution of this 

 moraine, the striae in nearly'' every instance being directed toward the 

 moraine. Plummer, many years ago, discussed striae discovered by him 

 near Richmond.^ They are of interest, not only because of their value in 

 indicating the direction of ice movement, but also because they are 

 apparently the first striae ever reported from that State. They are found 

 in a quarry of blue limestone on the west side of a small stream tributary to 

 the East Whitewater, 2 miles north of Richmond. A very hard clay rested 

 on the striated surface, and above this deposit were gravel, sand, clay, and 

 soil, the whole occupying 15 feet. The bearing of the striae is S. 20° W. 

 Plummer gives the following description : 



The grooves vary from a mere scratch to furrows an inch or more wide, and 

 with one or two exceptions running exactly parallel with each other. The average 

 depth of these grooves is perhaps one-eighth of an inch,- and their breadth and 

 shallowness give to the surface of the rock a vitiated appearance. 



1 Geology of Ohio, Vol. Ill, p. 285. 



■^ Suburban Geology of Richmond, Indiana, by John T. Plummer: Am. Jour. Sci., 1st series, Vol. 

 XLIV, 1843, pp. 281-313.' 



