GEOLOGY AND PALEONTOLOGY OF THE SCHOHARIE VALLEY 347 



would require that the summit of the crystallines now constituting 

 the Hudson Highlands should have been on a somewhat lower 

 level than that of the peneplain to the north, east or west. Thus 

 the Hudson slowly cut its gorge through the hard crystallines 

 while at the same time the valley above was widened in the more 

 easily eroded strata. Above the Highlands the Hudson has the 

 habitat of a subsequent stream, but at that point it changes its 

 entire character, becoming at once an abnormal type of stream, 

 such as could only be produced by superposition, either on a 

 peneplain or through the intermediation of coastal plain strata 

 which formerly covered the crystallines. Of these two views the 

 first appears to be the correct one. 



Minor erosion features of the Schoharie region. Though the three 

 principal streams of this region have cut their valleys without 

 much regard to the character and position of the strata, for 

 reasons already discussed, all the minor erosion features are fully 

 in accord with the character of the beds from which they are 

 carved. The prominent terraces of West hill or Terrace mountain 

 are a striking example of the control which the strata exert, for 

 here each hard bed has formed a prominent cliff, while the softer 

 beds have produced slopes between the cliffs. The retreat of the 

 cliffs is largely due to the weathering of the softer strata, through 

 which the support for the limestones is removed, whereupon the 

 latter break down in blocks, leaving a vertical cliff. Good ex- 

 amples of this retreat may be seen on the cliff of West hill, and 

 on the road leading up Barton hill from Shutter's Corners. 

 Among the most interesting results of rock weathering in this 

 region is the formation of rock shelters at the base of the heavy 

 limestone beds. These shelters are often of fair size, and will 

 easily protect a small party during rainstorms. They are com- 

 mon along the contact line between the Manlius and Coeymans 

 and between the New Scotland and Becraft, the best examples 

 being found on Dann's hill [see pi. 10-12]. One of the mosl 

 interesting of these shelters is behind (he house of Mr Samuel 

 Clarke on Dann's hill, and aboul a hundred feet above the road. 

 It is worn along the New Scotland-Becrafl contact line, the 



