and hydrography of Buzzards Bay have been performed (Peck, 1896; 

 Sumner et al. , 1913; Fish, 1925; Hough, 1940; Moore, 1963; Anraku, 

 1962, 1964; Strahler, 1966; Pearce, 1969; Driscoll, 1975; Rosenfeld 

 et al. . 1984) . The survey branch of the New England Division (NED) 

 of the Army Corps of Engineers also performed a bathymetric survey 

 of the Buzzards Bay Disposal Site in July 1985 „ Buzzards Bay lies 

 along the southern boundary of the crystalline bedrock forming the 

 interior Massachusetts lowlands and to the west of the glacial 

 debris-covered insular complex of the Cape Cod-Elizabeth Islands 

 (Figure 2) . The long axis of the bay runs northeast-southwest for 

 approximately 46 kilometers from Onset Bay to Penikese Island. At 

 its widest, the Bay is approximately 19.5 kilometers across. The 

 Bay is open to the south and, along part of the eastern boundary, 

 there is appreciable water exchange with Vineyard Sound. There is 

 also some water exchange with Cape Cod Bay through the Cape Cod 

 Canal. Buzzards Bay is relatively shallow, averaging 11 meters in 

 depth. The disposal site is located in the northern half of the 

 Bay and lies within a slight depression, between the 9m (30') and 

 12m (40') isobaths (Figure 3). 



3.2 Sediments 



Silt-clay sediments occupy the deeper portions of the 

 Bay. Fine sand occurs in nearshore, depositional areas in the 

 north, while medium sand predominates in southern, nearshore 

 regions. Coarse and medium sands are found in the vicinity of 

 rocky exposures around New Bedford Harbor, off Nasketucket Bay, and 

 along the entire northeast shoal areas of the upper bay (Figure 4) . 

 In general, the main portion of the Bay is dominated by two major 

 textural facies. Fine-grained silts occur throughout the deeper 

 portions and troughs, while sands are found in the shallow, higher 

 kinetic energy areas. On the basis of the thickness of 

 fine-grained sediment that has accumulated since the Pleistocene 

 epoch, Hough (1940) estimated an average sedimentation rate of 2.3 

 mm/yr. More recent radiocarbon dating estimated range from 0.52 

 to 0.84 mm/yr (Young, 1971). 



In the region of the disposal site, a complex topography 

 and mixture of sediment types are evident. Sidescan sonar and 

 REMOTS® sediment-profile surveys were performed to illustrate 

 efficient and cost-effective techniques of mapping the geological 

 and biological properties of the seafloor. The two systems mapped 

 topographic features, sediment texture, and biological successional 

 stages within the Buzzards Bay Disposal Site (Menzie et al. , 1982) . 

 Six major textural regions were revealed (Figure 5) : 1) a disposal 

 mound top, 2) a small wave-like field possibly consisting of large 

 sand waves overlying silt-clay sediments, 3) a cratered bottom, 4) 

 a rubble bottom, 5) an eastern flat bottom, and 6) a western flat 

 bottom. Menzie et al . (1982) interpreted the east and west flat 

 bottom regions to represent ambient seafloor, unaffected by 

 disposal operations. The mound top, a circular region 

 approximately 500 meters across, apparently reflects the center of 



