B. Bottom Sampling 



In Penobscot Boy and Its approaches, 143 grab samples and 74 cores were taken. 

 Station locations are shown in Figure 2. The grab samples were taken with an orange 

 peel sampler. Most of the cores were obtained with a modified Kullenberg piston 

 corer using a 12-foot core barrel . A few Phleger gravity cores were attempted 

 where it was suspected that the sediment cover over bedrock was thin. In general, 

 excellent undisturbed Kullenberg cores were obtained. Full penetration and a high 

 percentage of recovery was the rule. Stratification in the cores was nearly always 

 horizontal, and only a few Instances of sucked, pulled-apart, or otherwise disturb- 

 ed cores were found . 



All samples were analyzed by the U.S. Naval Oceanographic Office Geolog- 

 ical Laboratory for grain-size distribution using the standard wet-sieve and pipette 

 methods. The cores were sub-sampled where color or grain-size changes were noted 

 or suspected. Samples were taken above and below such changes. In homogeneous 

 cores the sampling interval was usually about 24 inches. It should be noted that at 

 the time the samples were analyzed the cutoff from silt to clay was at 9^ (0.002 mm) 

 in accordance with engineering procedure Instead of 8 p (0.004 mm) which is cus- 

 tomary with geologists. The result is that many samples on the analysis sheets (see 

 the Appendix for the analysis sheets) are classed as clayey silts rather than silty clays 

 as they would have been if geological usage had been followed. The usage fol- 

 lowed in the text, diagrams, and charts, makes the silt-clay separation at 8/. The 

 ^^ values were obtained from cumulative curves not presented in this report. Grain- 

 size determinations were not carried beyond 9 p ; consequently the third quartile for 

 very fine sediments was not reached and statistical measures could not be obtained. 



C . Sonoprobe Runs 



The Sonoprobe runs were made with the instrument mounted aboard the USS 

 LITTLEHALES (AGSC-15). Runs usually were made at speeds of 3 to 5 knots and at 

 various chart speeds. For this reason, the horizontal scale of the recordings varies 

 from run to run. The vertical exaggeration of the records ranges from 15 to 60 times, 

 For convenience, horizontal lines representing 500 yards have been drawn on the 

 records reproduced in this report. 



Eleven Sonoprobe runs were made in the survey area for a total of 70 miles of 

 tracks. In addition, short runs were made at most of the coring sites. Deep pene- 

 tration and excellent definition of subbottom features were achieved on most of the 

 runs . 



