Late Glacial Origin of the Maumee Valley Terraces, Northwestern Ohio

Four major paired terraces and six short local terraces have been identified along the Maumee River valley between the Ohio-Indiana state line and Perrysburg in northwestern Ohio by detailed field mapping and study of gaging-station records, water-well logs, and soils data. From highest to lowest, the paired terraces have been named the Antwerp, Florida, Napoleon, and Grand Rapids terraces. The three higher terraces are correlated with Glacial Lakes Warren I and II, Lake Wayne, and Lake Grassmere, respectively, based on similarities in elevation of the lowest end of the terraces and the lake levels. The lowest of the four major terraces, the Grand Rapids Terrace, is rock-defended, controlled by outcrops of the Silurian Tymochtee Dolomite in its channel at Waterville. The short local terraces appear to be related to short-lived stages in the cutting of the Maumee Valley. Although some may correlate with one of the major terrace systems, such correlations remain tentative because of the isolation of these local terraces. OHIO J. SCI. 93 (5): 126-133, 1993 INTRODUCTION The Maumee River is the largest river draining northwestern Ohio. It heads in Indiana, and is fed by tributaries in Indiana, Michigan, and Ohio, creating a drainage basin encompassing approximately 19,425 km (7,500 mi) (Cross and Weber 1959). The Maumee River flows across a broad, low lake plain formed by icedammed lakes in the Erie Basin during the retreat of the Wisconsinan ice sheet (Leverett 1902; Leverett and Taylor 1915; Carman 1930; Forsyth 1966, 1970, 1973; Calkin and Feenstra 1985; Coakley and Lewis 1985; Eschman and Karrow 1985). A history of these glacial lakes (Table 1) and the general positions of their shorelines in northwestern Ohio (Fig. 1) have been determined. The lake plain in northwestern Ohio is underlain by lake-modified till and lacustrine sediments (Forsyth 1965, 1966) which in turn are underlain by Middle Silurian to Upper Devonian rocks which dip gently northwest into the Michigan Basin (Forsyth 1966, Dorr and Eschman 1970, Herdendorf and Braidech 1972). The Maumee River began as an extended consequent stream flowing across newly exposed lake bottom when the level of Lake Maumee I, first and highest of the late Wisconsinan glacial lakes fell, exposing the western portion of the Erie Basin (Carman 1930). The mouth of the Maumee River alternately extended eastward or became flooded as lake levels rose and fell with shifts in the position of the glacial margin. On several occasions, the ice dam in the Buffalo, NY, area receded far enough north to allow the impounded Erie Basin waters to drain eastward briefly. This caused a temporary but drastic fall in lake level and a resulting extension of the Maumee River eastward across the exposed lake bottom. These events occurred during Arkona (Ypsilanti) stage before the Maumee Valley had formed, during Wayne stage, and probably during Grassmere/Lundy stages (Kunkle 1963, Calkin and Feenstra 1985, Eschman and Karrow 1985). The greatest such eastward extension of the Maumee TABLE 1 Glacial Lakes in the Erie Basin.