426 ANNALS NEW YORK ACADEMY OF SCIENCES 



marls and greensand marls of the upper Cretaceous; and it is probable, as 

 others have suggested, that the deposition was continuous without important 

 break through Eocene time. The original inland extension of this mantle 

 of conformable sediments is clearly indicated by the southeastward deflec- 

 tion of the Connecticut River at Middletown and of the Housatonic River 

 in approximately the same latitude. Entering at these points upon the 

 newly-formed coastal plain, the rivers, released from the control of the 

 bed-rock structure, naturally took the most direct course seaward; and 

 subsequently, through the erosion of the Cretaceous mantle, found them- 

 selves superimposed upon the bed-rock in the obliquely transgressive and 

 unsympathetic relation which we now observe. The Hudson, on the 

 contrary, has felt throughout its history the efficient control of the conti- 

 nental re-entrant into which it debouches. 



The continental elevation which finally terminated the Cretaceous- 

 Eocene deposition was probably at least equal to the present relief of the 

 Cretaceous peneplain; and it may have been much more than this. It 

 made possible the rapid erosion of the uplifted sediments and, probably, 

 the trenching of the underl}dng peneplain. From this time, apparently, 

 dates the wide and deep transverse valley which divides the Cretaceous beds 

 in the western part of Long Island and which Veatch has called the valley 

 of Sound River. In this valley was deposited, probably by stream action, 

 the so-called Jameco Gravel, containing a high percentage of granitic 

 detritus, which Veatch has regarded as the product of early Pleistocene 

 glaciation. The granite pebbles, although now in an advanced state of 

 decay, are well rounded or water-worn, showing that they must have been 

 firm and undecomposed at the time of their deposition. The composition 

 of this gravel suggests that the post-Eocene elevation may have been suffi- 

 cient to induce glaciation. But, whether of glacial or non-glacial origin, 

 this dark gravel, which blends upward with clays of probable Tertiary age, 

 should be referred to the Tertiary series and not to the Pleistocene. 



During the deposition of the Jameco Gravel, the land subsided to a 

 position of comparative stability at the Tertiary base-level and the develop- 

 ment of the Tertiary or Piedmont peneplain, under the joint agency of 

 subaerial and marine erosion, began. The fluvial portions of the Tertiary 

 base level, developed, for the most part, on comparatively weak rocks, have 

 gained general recognition as the broad valley floors of the Hudson, Con- 

 necticut and other rivers. But in New England, at least, the marine con- 

 tribution to this base-level, developed chiefly on relatively resistant crystalline 

 rocks, has usually failed of differentiation from the older and far more 

 continuous and complete Cretaceous peneplain. Profiles normal to the 

 coast show, nevertheless, a more or less distinct terrace, and show, further, 



