Flexures in the Laminae of Clay. 



175 



The preceding section was obtained on the side of a gully, a few 

 rods west of the stage road at Long Hill, two miles south of Deer- 

 field north village. The last year, I obtained the following sketch 

 from a clay pit, recently opened, a few rods east of the Academy, in 

 Deerfield. The contorted portion of the wall of the pit, was about 

 three feet in perpendicular thickness ; and above and below, (as shown 

 on the sketch,) the layers of clay were perfectly regular and horizon- 

 tal. This proves beyond all question, that the disturbance must have 

 taken place during the period of the deposition of the clay ; and that 

 the cause must have been a transient one. A few rods farther to the 

 east, however, as we pass up a hill, a similar disturbance of the lay- 

 ers of clay appears at a higher level, and of several rods in length ; 

 proving that the cause, whatever it might be, recurred at intervals. 

 This case differs from the one first described, in there being no in- 

 terstratified layers of sand, as are shown in the preceding sketch. 



Contortions in the Clay Beds : Deerfield. 



Position and thickness of the Strata. 



There is no evidence, that I have ever been able to find, to prove 

 that these tertiary strata have been disturbed since their original de- 

 position. Nevertheless, the layers, or strata, are not always exactly hor- 

 izontal. Where the surface beneath is slightly undulating, the laminae 

 of clay are conformed to the irregularity. This produces a dip some- 

 times of two or three, or even five degrees, and in one or two cases 

 (the east side of north Sugar Loaf mountain, in Deerfield, and the 



