Figure 3. Linear shoal field off the Delraarva Peninsula 

 (Field 1979) 



37. Some early investigators believed that linear shoals were remnants 

 of drowned barriers overstepped during the Holocene marine transgression which 

 occurred as a result of a general rise in sea level following the late Wiscon- 

 sin glaciation. Later research has strongly suggested that they probably 

 formed during the Holocene transgression in the shore -face zone of beaches, 

 retreating across the shelf in response to rising sea level, and were subse- 

 quently detached by continued retreat of the shoreline (Duane et al . 1972). 

 Shore- face connected shoals, apparently in the formative stage, presently 

 exist in many places and support the suggestion that isolated shoals farther 

 seaward initially formed as shore-face connected shoals. 



38. Cores from many linear shoals on the Atlantic shelf have been 

 obtained by CERC and others during the past two decades. In nearly all cases, 

 the shoals were found to consist of unconsolidated sand-size material which in 

 places contains various amounts of gravel. Seismic reflection profiles across 

 linear shoals often reveal a strong reflector passing beneath the shoal at the 

 approximate elevation of the intershoal sea floor. Cores between shoals that 



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