REVIEWS 589 



erin^ than the Illinoian drift. The Illinoian drift is exposed outside the Wisconsin 

 drift from central Ohio westward to the Mississippi River, but is discussed only as far 

 west as the re-entrant angle in the glacial boundary in southern Indiana, the portion 

 farther west having been discussed in Monograph XXXVIII. The main topics con- 

 sidered are structure, topographic expression, and the character of the glacial drainage. 



The weathered zone and accompaning soils and peat beds which occur between 

 the Illinoian drift and the overlying loess are described in their exposures outside the 

 Wisconsin drift, and to some extent within the limits of that drift. 



The lowan drift does not appear to be exposed in this region outside the Wis- 

 consin drift, but a deposit of silt with loess-like characteristics occupies the horizon 

 of this drift-sheet, and covers the weathered surface of the Illinoian drift. There 

 appears to have been but a brief interval between the deposition of this silt and the 

 Wisconsin glaciation, if we may judge by relative amounts of weathering. An inter- 

 val of some importance may be inferred from the change in the attitude of the land 

 by which better drainage conditions became prevalent in the Wisconsin stage of gla- 

 ciation than attended the loess deposition. The marked difference in the outline of 

 the lowan and Wisconsin borders also indicates an interval of some consequence. 



The early Wisconsin drift is less extensively exposed in this region than in that 

 covered by the Illinois glacial lobe discussed in Monograph XXXVIII, there being 

 in southwestern Ohio but one moraine and narrow till plain which seem referable to 

 this drift, while in central and eastern Ohio and northwestern Pennsylvania it is not 

 known to be exposed. The evidence of an interval between the early and late Wis- 

 consin glaciations is more clearly shown in the region covered by the Illinois glacial 

 lobe than in this region, for there the border of the outer moraine of the late Wiscon- 

 sin group is strikingly discordant with that of the neighboring moraine or moraines of 

 the early Wisconsin group, while in this region there is not a marked discordance. 



The moraines of the late Wisconsin stage consist of an outer or main morainic 

 system, which was brought to notice by Chamberlin in the Third Annual Report of 

 the U. S. Geological Survey, and several minor moraines which appear in a somewhat 

 regular succession between the main morainic system and the Lake Erie basin. 

 Eskers are found in Ohio, Pennsylvania, and New York on the till plains between 

 the moraines, but drumlins are restricted to the western New York portion of this 

 region. 



The great glacial lakes, Maumee, Whittlesey, and Warren, which were formed 

 in front of the retreating ice-sheet as it withdrew into the Huron and Erie basin, are 

 each shown on double-page maps, while their beaches and outlets are discussed in 

 some detail. A marked warping of the beaches in Pennsylvania, western New York, 

 and the province of Ontario testifies to differential uplift which has occurred since the 

 ice retreated from this region, and which apparently is still in progress. The portion 

 of the beaches in Ohio shows very little warping or differential uplift. 



The monograph closes with a discussion of the soils, which are classified accord- 

 ing to their origin, the following classes being recognized : residuary soils, bowlder- 

 clay soils, gravelly soils, sandy soils, loamy soils grading into fine silts, peaty or 

 organic soils. 

 MosELEY, E. L. Submerged Valleys m Sandusky Bay. Nat. Geog. Mag., 



Vol. XIII, pp. 398-403, 1902. 



Borings made in Sandusky Bay, have brought to light an old channel of the river 

 and channels of some of its tributaries leading across the bed of the bay. They are 



