CAPE COD GEOLOGY 



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folds rest unconformably upon them, and the upper boulder bed, which is 

 probably of Wisconsin age, extends over beds of sand and clay that lie upon 

 gravel of the same age as that on which these supposed Wisconsin boulders 

 rest in areas farther south. These beds of sand and clay are older than the 

 Gardiners clay and the overlying Jacob sand and Manhasset formation, which 

 come into view still further north in unmistakable character and which have 

 nothing in common with the beds here considered. On the other hand, although 



Fig. 19.— Cross section of Clay Head in 1916, showing overturned compressed anticlines 

 or isoclines accompanied by overthrust. A. Upper Cretaceous white clay; B, Dukes 

 boulder-bed; C, Weyquosque formation (gravel and drab sand) ; D, unconformity (post- 

 Mannetto interval) ; E, bouldery gravel; F, glacial sand; G, Wisconsin (?) bouldery drift; 

 H, subsoil of sand and clay. The beds lettered E and F probably represent the Jameco 

 formation. 



the Manetto stony blue clay till of the Gay Head section has not been recog- 

 nized in the folded beds at Clay Head, it may antedate the strong overturning 

 shown at Clay Head, as it does at Gay Head, and the overturning, the erosion 

 of the folds, and the consequent unconformity may be of the same age in both 

 sections. As the folded beds in the section at Clay Head lie below the horizon 

 of the Gardiners clay and do not include the Jameco gravel, the sand and 

 gravel of the beds lettered E and F in fig. 19 may represent the Jameco forma- 

 tion, at the base of which is a glacial bouldery deposit not shown so well else- 

 where. 



Just north of the Clay Head folds there is a broad anticline in which the 



