WEST 

 666 



200 



'NAVIGATION FIX NUMBERS ^ X 

 667 , 668 , 669 670 



. I I I I I U- 



671 



672 



L.."i- I I I u 1 1 I I I I--.-J.--. 



EAST 

 673 



CORE 31 

 (114 ft fn-tnedcl. sd) 



CORE 119 



(5 ft. fn-med. sd) 



PLEISTOCENE DEPOSITS 



CORE 30 

 (13 ft. fn-med. sd) 



COASTAL PLAIN STRATA 



HORIZONTAL DISTANCE APPROX. 6 NAUT ICAL MILES 



LINE 18 



Reduction of seismic line 18 (Fig. 2) exhibiting the eroded Coastal Plain surface at —150 feet (—45 meters) 

 MSL and the broad Three Mile buried channel which is traceable northward into Long Island Sound. The 

 three cores indicate the channel fill is clean, fine to medium, quartzose sand. 



(^ 



1 



^s 





B/oc* Island Sound 



'"^Vy / 1 ^--^Montauk 



•^ ) Point 



Line 18 , 





•c- 



30 



C-19. ,C-I8 ,;„,,^ 



C-31 



•c- 



-119 



C-21 C-16 



WEST 



/■ 



NAVIGATION FIX NUMBERS- 



EAST 



467 468 469 470 471 



_.! I 1 I L_ 



CORE 21 CORE 19 



472 473 474 475 476 477 478 479 480 481 



1 1 I J I I I I L_ 



CORE 18 



CORE 16 



SAND WAVES 



(7 ft med sd ) (4-2 f t. med-cse (15.3 ft. fn-cse. sd.) 1(6.3 ft. med sd.) 



^ 



V 



HOR. DIST APPROX. 6 NAUTICAL MILES 



LINE 14 



Reduction of seismic line 14 (Fig. 2) showing three buried channels which transect the southern fork of Long 

 Island. The sand waves off Montauk Point have ampUtudes of 20 feet (6 meters) and probably originate from 

 high-velocity tidal currents. The foiur cores show the subbottom is composed of a mixture of fine to coarse, sand 

 and gravel. Shading identifies Quaternary sediments. 



Figure 10. Geologic profiles of seismic reflection lines 14 and 18. 



35 



