242 H. L. FAIKCHILD PLEISTOCENE MARINE SUBMERGENCE 



east of Hartford, 100 to 200 feet (theoretic plane, 275); in Long 

 Meadow, south of Springfield, 200 feet (theoretic, 300) ; Turner Falls 

 and- Greenfield, 300 feet (theoretic, 375) ; Hanover, 500-540 (theoretic, 

 565) . Passing north, the broad plains more nearly approach the marine 

 level. 



If -the highest of the broad "flats" in the open valley could reasonably 

 be regarded as indicating the primitive level of the river flood, they cer- 

 tainly can not be so considered for static waters. * 



In the lowering waters the conditions for production of cliffs and bars 

 became more and more unfavorable. The deltas, being proportionately 

 of finer material, were spread out thinner into indefinite shape and not 

 so clearly correlated with the contributing tributary streams. When the 

 waters became quite contracted the southward currents were still more 

 effective and the detritus still better distributed. Eventually the south- 

 ward currents of the narrow sections became continuous throughout the 

 valley and constituted the primitive postglacial Connecticut River. 



Absence of marine Fossils 



The two chief objections to the theory (or fact) of marine submergence 

 will be : first, the lack of conspicuous summit-level phenomena, and, sec- 

 ond, the absence of marine organisms. The weakness of the shore phe- 

 nomena at the higher levels has already been sufficiently discussed. 



The lack of marine fossils in the Connecticut Valley terraces is not 

 proof of non-marine origin, for the negative evidence is inconclusive. 

 No fresh-water fossils are found, which fact might be used as argument 

 against the river theory. We know that large terranes of oceanic origin 

 are quite destitute of organisms. But there is a positive and satisfactory 

 explanation of the absence of fossils in these sediments. 



Even at the summit level the sealevel waters in the valley had connec- 

 tion with the open sea only through the straits at Middletown and New 

 Haven. The lower waters had only one pass to the sea, through the Mid- 

 dletown narrows. Moreover, the valley waters were always freshened by 

 the drainage from the north, and at the higher levels received the copious 

 flood of cold water from the melting ice-sheet. The waters were estua- 

 rine, and probably only the southern waters were even brackish. The 

 term 'lakes," applied by Emerson, is not inappropriate. 



Marine fossils. have been reported, but not always verified, from ele- 

 vated points on Long Island and from various localities in New England. 

 They should be sought in the valleys of Connecticut which open freely 

 southward, but probably they will not be found in the valley of the Con- 

 necticut River, 



