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vrw York stvtk \rrsKi'M 



the Manhasset shikLs. The deposit, now largely removed for 

 inason^s supplies, exhibits a strong flexure with a downthrow to the 

 south. On either side of this flexure the beds are horizontal but 

 those on the north belong stratigraphically below those now on the 

 same level but on the south of the flexure. Tlie annexed cut 

 (fig. 8) as sketched from a photograph exhibits the sand beds in 

 the top of flexure. The truncation of the flexed beds at the 

 present surface is sufflcient evidence of the erosion of the whole to 

 its present level. A few small glacial erratics occur on the surface, 

 but the ice sheet appears to have swept over it without leaving 

 other deposits. The top sands have lost their stratiflcation but it is 

 impossible to say how far this disturbance was due to the ice sheet 

 and how much has ])een done bv tho. LTowtli of plant roots in the 

 subsoil. 



The small heads of Cretaceous clay appearing above sealevel on the 

 ?hore of Manhasset bay, where the older Pleistocene is essentially 

 horizontal, along with the protruding masses of these older clays in the 

 massive portions of the section, indicate a relatively early disloca- 

 tion of por- 

 tions of the 

 pre- Pleisto- 

 cene base- 

 ment of the 

 island. It 

 would there- 

 fore appear 

 that the dislo- 

 cations were 

 not all of the 

 same date in this portion of the island, ranging in age from at least 

 the oldest Pleistocene to the time of the main moraines, certainly 

 none of them are later than the Port Washinjrton stasre. 



The upper limit of the Columbia accords roughly with the hight 

 assigned to the plains described as lying north of the inner moraine, 

 that is to say, the <lep<j6its are approximately delimited by the 200 

 foot contour line. Where lower, they have been eroded ; where 

 liigher surfaces exist, later glacial drift, usually till, is found cover- 



Fig. H Southward dipping flexed beds in Manhasset sands at Tom point 

 near Port Washington, stiowing eroded surface 



