of vibracore data precludes any interpretation from this survey. However, 

 because the area probably contains a sizable quantity of sand, the following 

 data on bathymetry and bottom sediment are included from Hartley's (1960) study. 



a. Bathymetry and Bottom Sediment . Maumee Bay is very shallow and bounded 

 by low clay shores and marshland. The maximum natural water depth is only 10 

 feet below LWD. The shipping channel is dredged and maintained at 25 feet below 

 LWD. 



The sand and gravel deposit is a low ridge widening from less than 0.5 mile 

 at Little Cedar Point to more than 2 miles at its northern end near Turtle 

 Island. On the western and northern sides the deposit terminates abruptly with 

 a rather sharp sand-mud boundary. Eastward the change to mud is indefinite and 

 there is no mappable boundary. 



The western and northern sides of the deposit are also relatively steep. 

 The higher surfaces of the deposit rise to a maximum of about 7 feet above the 

 general bottom level. Turtle Island, actually a part of the deposit, rises a 

 few feet above water level. 



The majority of the sand is fine grained. The remainder is coarse sand 

 and gravel; there is a conspicious lack of medium-grained sand in the deposit. 



Quartz and feldspar make up an average of 85 to 90 percent of the grains 

 in the fine sand sizes, 50 percent of the medium sand particles, and little 

 or none in coarse sizes. Limestone and shale particles, increase as do crys- 

 talline rock particles, as the grain size increases. 



b. Subbottom Sediment and Sand Volumes . The unconsolidated surface deposits 

 in Maumee Bay overlie firm clay which is of two types, lacustrine clay deposited 

 in the present lake and glacial clay till containing many small rock fragments. 

 It appears that the surface of the till is undulating and that the depressions 

 have been filled with lake clays and silts. Hartley (1960) estimated that there 

 is about 49 million cubic meters of sediment above the clay surface within the 

 deposit area. 



The poor seismic records and lack of vibracore coverage preclude an accurate 

 recalculation of sand volume in this deposit. Moreover, because the overall 

 nature of the deposit is similar to that of the Cedar Point area the fine-grained 

 nature of the sand may limit its use for beach nourishment. 



IV. SUMMARY AND RECOMMENDATIONS 



The primary objective of this study is to provide a general evaluation of 

 the Lake Erie shallow subbottom between Conneaut and Toledo, Ohio, for potential 

 sand and gravel deposits suitable for beach restoration and maintenance programs. 

 Primary survey data consist of 690 kilometers of high-resolution seismic reflec- 

 tion profiles taken between Conneaut and Toledo, and 58 vibracores with a maximum 

 length of 6.1 meters taken between Conneaut and Marblehead. About 25 percent 

 of Ohio's open lake part of Lake Erie was covered in the seismic reflection 

 survey. Water depths in the study area range from about 4 to 21 meters. 



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