surface is incised by at least 25 small, relict, buried channels. The 

 width of the channels varies from several hundred to several thousand 

 feet; thalweg depths range from 15.8 to 30 meters (52 to 98 feet) below 

 sea level. Side slopes and orientation are variable and since most chan- 

 nels were depicted on records from a single crossing, side slopes may be 

 only apparent. Two long profile lines parallel to the baymouth barrier 

 that closes off Rehoboth and Indian River Bays show numerous ancestral 

 channels (Fig. 17). Sheridan, Dill, and Kraft's (1974) study shows the 

 trend of these channels across the inner shelf quite clearly (Fig. 16). 



The location and thalweg depths of shelf channels between Bethany 

 Beach, Delaware, and the Maryland-Virginia line are shown in Figure 18. 

 Channel orientation is presumed perpendicular to the coast, although 

 single crossings of channels make this difficult to substantiate. Channel 

 location appears to be somewhat related to adjacent coastal geomorphology. 

 Some of the channels are adjacent to or directly down-dip from present- 

 day streams; others have no obvious fluvial source and may be either 

 fluvial or tidal in origin. Approximately one-half of the channels lie 

 off the headland or barrier island embayed stream coastline (e.g., Isle 

 of Wight Bay) and the other half are adjacent to the barrier island lagoon 

 system (Ocean City to Virginia). With the exception of channels 1 and 2, 

 which are probably fluvial in origin, and channels 16 and 17, which are 

 probably tidal in origin, the majority of channels form an arc around 

 Ocean City. 



Plotted along the shoreline in Figure 18 are the approximate positions 

 of historic inlet sites, as given by Truitt (1967). According to Truitt, 

 these inlets appeared and are historically documented in maps and writings 

 at various times between 1649, when Fenwick Inlet was charted, and 1933 

 when Ocean City Inlet and Inlet Shallows were formed by a hurricane. 

 Since that date Ocean City Inlet has been periodically swept over by 

 storms; the largest was the 1962 storm, which also temporarily reopened 

 Sandy Point Inlet. Most of the inlets have a history of opening and clos- 

 ing at least several times within the past century or two. The number, 

 spacing, and position of these historic inlets are similar to that of the 

 shelf channels and serve to illustrate that a tidal inlet origin for at 

 least some of them is a valid hypothesis. 



To further investigate channel origins, an attempt was made to assess 

 possible trends between channel shape (Figs. 19 and 20) and position on 

 the shelf (i.e., northern versus southern channels, inshore versus off- 

 shore channels, and channels which lie along a projected channel path). 

 No such trends were noted. For example, channel 8, which is alined with 

 an apparent fluvial source onshore, does not differ in a discernible way 

 from channel 13 to the south or from channel 3 to the north and onshore. 



There exists an apparent clustering of channel locations with respect 

 to distance from shore. Most channels are within 3.6 kilometers (2 miles) 

 of the shore or between 5.4 to 10.8 kilometers (3 and 6 miles) from the 

 shore. This gap, which does not appear to be an artifact of the data 

 coverage (Figs. 2, 3, and 4), is particularly noticeable in the Ocean City 



47 



