Tudor Wharf Draft Environmental Impact Report EOEA # 674 



Bedrock According to available geologic 

 maps, bedrock in this area is assumed to 

 consist of Cambridge Argillite. Bedrock 

 was not encountered in any of the test 

 borings. 



Glacial Till Predominantly an unsorted 

 mixture of clayey sand and gravel to 

 sandy clay with occasional cobbles and 

 boulders. This strata was deposited, 

 typically directly above bedrock, by the 

 advance of glacial ice sheets during the 

 Pleistocene Epoch. The top of this strata 

 was encountered between El 1.5 and El - 

 10.5 (Boston City Base (BCB) ) . The 

 thickness of this strata was not 

 determined as none of the available test 

 borings were advanced into underlying 

 bedrock. 



Marine Sand A layer of silty fine sand 

 was found to overlie the glacial till 

 deposits which is typically deposited as 

 the result of fluctuating harbor levels. 

 This stratum ranges in thickness up to 

 12.0 ft where encountered, with the top 

 of the stratum was found to range from 

 approximately El 0.5 to 9.0 (BCB). 



Organic Soils A stratum of organic soils 

 consisting primarily of organic silt and 

 peat was found to overlie the glacial 

 till or marine sands. This strata was 



-49- 



