GLACIAL GEOLOGY OF THE COHOES OUADRANGLE 



27 



Fig. 5 Diagram showing terraces in delta of Hcosic river 



EROSION TERRACES 



Near Mechanicville on either side of the Hudson valle\' there 

 is a well-defined terrace at the 200-foot level. These terraces are 

 quite certainly of different origin from the other terraces bordering 

 the valley and described above as the upper and lov^er terraces 

 of the Lake Albany deposits. The terrace west of the river (south- 

 west of Mechanicville) stands 40 feet below the lower lake terrace 

 and is separated from the latter by a steep slope. It was evidently 

 formed by the cutting down of the inner portion of the area of the 

 lake terrace. The terrace on the east side of the river is likewise 

 evidently a terrace of erosion having been carved out of the Hoosic 

 delta deposits. 



It is evident that the currents -which formed these symmetrical 

 erosion terraces issued from the valley now followed by Anthony 

 kill. The west terrace has the location and trend of outlines which 

 would result from erosion by a western tributary river occupying 



