32 



historic dredged material exists at 215 cm. No ambient material was sampled in Core GC- 

 10. 



Core GC-3B, collected over the center of the NHAV 93 mound (41°09.134' N, 

 72°53.458' W), penetrated 185 cm into the New Haven sediments (Figure 3-9). The core 

 description indicates that the top 93 cm is composed of two layers of black, clayey silt, 

 representative of the CDM layer (Figures 3-10 and 3-11). The remaining 92 cm of 

 sediment displayed the various strata of the UDM deposit with alternating layers of silt and 

 sands. The multiple sediment horizons within the UDM component depict the 

 heterogeneity of material disposed over the center of the NHAV 93 mound. 



Core GC-9, obtained approximately 100 m northeast of the NHAV 93 mound apex 

 (41°09.175' N, 72°53.407' W), penetrated 131 cm into the New Haven Harbor sediments 

 (Figure 3-9). A visual description of Core GC-9 shows three layers of silt, sand, and shell 

 fragments making up the 89 cm thick cap (Figure 3-10). The sediment sampled from 

 90 cm to 1 10 cm was a uniform black, clayey silt and considered to be UDM. The second 

 UDM stratum, a layer of brown to black sand and gravel, was visible from 111 cm to the 

 penetration limit. 



Core GC-1 1 was collected on the northeast flank of the NHAV 93 mound 

 (41°09.264' N, 72°53.306' W) and is composed of both NHAV 93 and COS 94 dredged 

 material (Figure 3-9). The top 60 cm of sediment in Core GC-11 is consistent with the 

 clayey silt material used as CDM over the CLIS 94 mound (Figure 3-10). The alternating 

 layers of dark olive-gray and black clayey silt that extends from 60 cm to 120 cm 

 correspond to the NHAV 93 cap material, as collected in previous cores. New Haven 

 UDM was sampled at 120 cm of penetration and meets the dark, olive-gray, basement 

 material at 155 cm. The basement material is visible from 155 cm to the penetration limit 

 of 262 cm. 



Core GC-7, collected 50 m from the center of the mound, represents the southeast 

 quadrant of NHAV 93 (Figure 3-9). The core penetrated 223 cm into the sediments, 

 providing a cross-section of the CDM and UDM making up the NHAV 93 mound as well 

 as the ambient basement material (Figure 3-11). The top 67 cm of penetration represents 

 the clayey silt cap over the UDM deposit. Layers of soft black, and an olive-gray, clayey 

 silt overlay 147 cm of New Haven dredged material composed of a heterogenous mixture 

 of clay, silt, sand, and gravel. The bottom 9 cm of Core GC-7 is composed of olive-gray 

 silt, the ambient sediment at CLIS. 



Core GC-6 was obtained 60 m northwest of the mound center (41°09.182' N, 

 72°53.509' W) and penetrated 272 cm through NHAV 93 sediments and historic dredged 



Monitoring Cruise at the Central Long Island Sound Disposal Site, September 1995 



