UNCLASSIFIED 



Security Classificati< 



DOCUMENT CONTROL DATA -R&D 



■try ctassilication ot title, body of abstract and Indexing annotation must be entered when the overall report la clesettied) 



ORIGINATING ACTWIXTW (Corporate author) 



Department of the Army 



Coastal Engineering Research Center 



Kingman Building 



Fort Belvoir. Virginia 22060 



.2a. REPORT SECURITY CLASSIFIC* 



UNCLASSIFIED 



PLEISTOCENE-HOLOCENE SEDIMENTS INTERPRETED BY SEISMIC REFRACTION AND WASH-BORE 

 SAMPLING, PLUM ISLAND-CASTLE NECK, MASSACHUSETTS. 



- DESCRIPTIVE NOTES fTVpe o/ report and inclusive dafes^ 



5- AUTHOR(S) (Fin 



, middle initial, laa 



Eugene G. Rhodes 



REPORT DATE 



July 1973 



TOTAL NO. OF PAGES 



75 



OF REFS 



31 



*CT OR GF 



6. PROJECT NO. 



ORIGINATOR'S REPORT NUMBER(S) 



Technical Memorandum No. 40 



10. DISTRIBUTION STATE 



Approved for public release; distribution unlimited. 



SUPPLEMEN 



12. SPONSOR 



Department of the Army 



Coastal Engineering Research Center 



Kingman Building 



Fort Belvoir, Virginia 22060 



13. ABSTRACT 



The wash-bore method of soil sampling was found to be an excellent technique 

 for subsurface study in coastal areas. Phenomena to be considered when interpreting 

 seismic refraction records include a) the "blind zone," b) the non-zero time inter- 

 cept, c) , time gaps in the time-distance photo over buried peat, and d) variable 

 thicknesses of dry sand layers. 



The seismic method successfully located Pleistocene and bedrock topography. 

 However, glaciomarine clay did not show a seismic contrast with respect to sandy, 

 water-soaked sediments. Topography exposed during lower sea level has a dominant 

 influence on modern coastal geology. Barrier islands became anchored on Pleistocene 

 features as the sea level rose and deposition occurred in the estuaries behind the 

 barrier beaches. Major channels of the estuaries migrated landward with the sea- 

 level rise. 



No radiometric dates were determined from study samples but the sedimentary 

 stratigraphy fits the time frame of other investigators. 



DD 



POJIM 



1473 



UNCLASSIFIED 



Security Classification 



