Subbottom Structure 



Information on subbottom structure 

 near the tower site and along a traverse 

 from near shore to approximately a mile 

 and a half seaward of the tower was ob- 

 tained. This was done by using a con- 

 tinuous reflection profiler with a pneu- 

 matic acoustic repeating source fired at 

 a rapid rate (1/4 of a second) and a high- 

 resolution graphic recorder. The re- 

 flection of the transmitted sound is the 

 result of sound velocity, density, and 

 porosity contrasts along subbottom 

 stratified layers or surfaces of uncon- 

 formity. These reflections may be in- 

 terpreted as lithologic or structural units, 

 and, with the aid of core samples, may 

 be correlated with actual sediment units. 



50 — 



Prior to the installations of the tower, a core boring 

 was made at the proposed site which shows uncon- 

 solidated sedimentary layers to 63 feet. Superimposed 

 color shows the close relation of core hole data and 

 the sub-bottom structure as defined from later acoustic 

 reflection profiles. 



90 



vVx-K 



BROWNISH-GRAY MEDIUM TO 

 \ COARSE SAND WITH MANY 

 SHELL FRAGMENTS 



BLACK SAND-SIL 



LAYERS OF SHELL FRAGMENTS 



INTERBEDDED LAYERS OF 

 SAND-SILT-CLAY AND FINE SAND 



BROWNISH-GRAY SAND WITH SOME MUD 

 CONTAMINATION 



WEATHERED CONGLOMERATE (HARD BEDROCK 



