Has Finished His Big Task

HAS FINISHED HIS BIG TASK

Frank Leverett, Who Has Made Headquarters Here

U. S. GEOLOGICAL SURVEY

Glacial Formations and Drainage Features of the Erie and Ohio Basins

The U. S. Geological Survey has now in press Volume XLI of the Monograph series (pp. 1-802), containing an account of the "Glacial Formations and Drainage Features of the Erie and Ohio Basins," by Mr. Frank Leverett, who has been making his headquarters in Ann Arbor and who prepared the companion Monograph, Volume XXXVIII, on the Illinois Glacial Lobe. The area treated of in the present volume extends from the Genesee valley in New York, westward across northwestern Pennsylvania and Ohio to central and southern Indiana, and southward from Lakes Ontario and Erie to the vicinity of the Allegheny and Ohio rivers. It treats of the old drift of northwestern Pennsylvania, the Illinoian drift of Ohio, Kentucky, and southeastern Indiana, and the Wisonsin drift of the Maumee-Miami, Scioto, and Grand river lobes, as well as the drift of western New York. It includes the portions of the glacial lakes Maumee, Whittlesey and Warren, which border the Lake Erie basin on the south and west, and also their westward outlets. An outline of previous publications on the glacial geology of the region is given, and also an outline of the geologic formations and the several sheets of drift there present. The great variations of altitude are noted; the present systems of drainage are discussed, and an attempt is made to determine the causes of the changes of drainage in the past. For example: Premising that with the extension of glaciation into the lower courses of a northward-flowing stream there results a ponding of water in front of the ice and a consequent escape of the water over the rim of the drainage basin in some other direction; the writer holds that the Old Upper Ohio, of Monongahela system was diverted from its former northward course to its present southwestward course at a date at least as early as the culmination of the earliest placiation in the Upper Ohio region.

The drift border, or glacial boundary, is not, the author holds, a unit, but formed in part by the Wisconsin and Illinoian drifts, in part by a sheet of still older drift, perhaps pre-Kansan, which is exposed outside the Wisconsin drift, appearing to emerge from beneath it near the New York and Pennsylvania line east of the Conewango river, and to pass southward back and forth across the valley of the Allegheny river. This drift is shown to have suffered a much greater amount of weathering and erosion than the Illinoian drift, which has been identified no farther east than western Holmes county, in northcentral Ohio.

The characteristics, the outwash, and the glacial drainage of this, as of the Illinoian drift, are set forth. The evidence of the interval between the deposition of loess and associated silts and the Wisconsin glaciation is found in the relative drift, is described elaborately, particularly as appearing in the morainic loops of the Miami, Scioto and Grand river lobes, and in the minor moraines of the late Wisconsin stage lying between the main morainic system and the shores of Lake Erie and Lake Ontario.

The great glacial lakes, Maumee, Whittlesey and Warren, are taken up in order. Lake Maumee, the first of the glacial lakes to occupy the Huron-Erie basin, and bounded on the north and east by the retreating ice sheet, was limited on the south and west by a land barrier, over which it had successive outlets: one past Fort Wayne in northeastern Indiana, the Wabash-Erie channel, and, as the ice melted, another farther north past Imlay, Lapeer county, Michigan. Two Maumee beaches have been traced from Imlay southwest to Fort Wayne, and eastward to the Lake Erie basin between Gerard and Erie, Pennsylvania. The Imlay outlet probably cause the second lower beach. The Belmore beach of Lake Whittlesey, the successor of Lake Maumee and about thirty feet lower, is described throughout its course from southeastern Michigan southward and eastward to its apparent terminus at Marilla, in western New York. The Ubly outlet, across the "thumb" of Michigan, westward to the Saginaw basin and thence by the Grand River outlet to Lake Chicago, are briefly considered.

In like manner the extent, beaches, and outlet of Lake Warren, its relations to the ice sheet, and its lowering to Lake Iroquois, are discussed.

The last chapter treates of the soils in the Erie and Ohio basins, which are classified according to their origin as residuary soils, bowlder-clay soils, gravelly soils, sandy soils, loamy soils grading into fine silts, and peaty or organic soils.

The volume contains twenty-six plates and eight figure maps illustrating the topography, glacial area, glacial lakes, drainage, etc., of the region discussed.