Core 185, 6 feet (2 meters) long near the center of the site contained 

 mostly clean, brown quartz sand predominantly in the medium-size range. 

 Grain-size data for samples from this core are in Appendix B. The esti- 

 mated composite mean diameter of the cored material is 1.84 phi and the 

 phi sorting is 0.84. Core 184 on the border of the deposit contained 2 

 feet of similar material at the surface underlain by fine sand. The area 

 of the deposit is estimated to be 407 X 10^ square yards; assuming an 

 average thickness of 5 feet (1.5 meters), the volume available is 

 0.68 X 10^ cubic yards. 



(4) Nantasket Center . This sand deposit is centered at 42°17.8'N.j 

 70°49'W. about 2.2 nautical miles (4.1 kilometers) off Nantasket Beach. 



The site lies in 65 feet (19.8 meters) of water and occupies a slight 

 topographic swale immediately north of a low steep-faced outcrop of the 

 acoustic basement (Figs. 21 and 22). Only one seismic reflection profile 

 (line M; Fig. 21) crosses this deposit. On this profile (Fig. 22) the 

 deposit appears situated in the transparent acoustic unit which fills a 

 small depression in the acoustic basement. 



The transparent unit is divided into the typical upper and lower 

 acoustic subunits with the upper unit filling a depression in the lower 

 unit. Strong internal reflectors in the upper unit indicated northward- 

 dipping bedding planes in the deposit. 



Core 181, 7 feet (2.1 meters) long, was taken from the central part 

 of the deposit area and contained clean, gray quartz sand in the fine to 

 medium sand range. The estimated composite mean diameter of the cored 

 material is 2.46 phi (0.182 millimeter); the estimated phi sorting is 

 0.78. All of the upper unit is probably composed of similar sand; there- 

 fore, the deposit may be a maximum of 25 feet (7.6 meters) thick at its 

 thickest point. The one areal dimension determined from the available 

 profile showed the deposit to extend 600 yards (548 meters) in a north- 

 south direction. Assuming that the other surface dimension is at least 

 one-half and that the sand is 25 feet (7.6 meters) thick, a volume of 

 1.50 X 10^ cubic yards' of suitable material is estimated in this deposit; 

 a thickness of only 7 feet would give an available volume of about 0.42 X 

 10^ cubic yards. 



(5) Nantasket West. This site, centered at 42°17.2'N., 70°51.2'W. 

 approximately 0.7 nautical mile (1.30 kilometers) off Nantasket Beach 

 (Fig. 14) , lies in an area of nearly level bottom which slopes northward 

 from about -25 to -40 feet (-7.6 to -12.2 meters) MLW (Fig. 23). 



A north-south seismic reflection profile crossing the site shows the 

 deposit in the upper reflection facies of the transparent unit (Fig. 24) . 

 The facies contain strong internal reflectors and near the south end of 

 the deposit the internal reflectors indicate probable high-angle bedding 

 dipping southward. 



Two cores penetrated the upper part of the Nantasket West deposit. The 

 northernmost core (173) recovered 11 feet (3.4 meters) of medium sand. To 



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