337 



This display of colors retains its beautiful appearance 

 until we approach the surface of the clay, where, from 

 long exposure to the influences of sunlight and the wea- 

 ther, its whole upper portion, whenever revealed to the 

 eye, becomes one uniform tint of yellowish drab. 



This upper division, or drab-colored variety of the marly 

 clay, is usually separated from the horizontal, variously 

 colored and dark-stained mass beneath, by a single im- 

 bedded deposit of fine-grained, deeply tinged yellow sand, 

 amounting in many places to some considerable degree of 

 thickness. This drab-colored portion of .the clay consti- 

 tutes about one-third of the entire formation, and it is 

 through its numerous layers alone that the disturbing 

 agencies appear to have exerted their most powerful ener- 

 gies. The heavy primary boulders and other detrital 

 materials from the northern section of the State, during 

 the violent agitation of the waters which drained and left 

 bare <o large an extent of our tillable lands, have grooved 

 out deep and parallel trenches, running in a direction 

 nearly north and south, and, after disrupturing the strata 

 and giving origin to those many faults and slides which 

 everywhere prevail, may now be seen piled up in the 

 greatest profusion all along the base of the heavy lime and 

 sandstone cliffs which form the northern termination of 

 the Helderberg mountains. 



This disrupturing agency has, in many instances, forced 

 its way between the strata of this variety of clay at various 

 elevations ; sometimes raising the overlying mass so as 

 to cause it not unfrequently to assume the regularly arch- 

 like form, and leaving the intervening spaces completely 

 filled with fine-grained gravel or l>eds of sand ; at other 

 times it has fairly inverted the strata, and thrown them 

 about in every variety of confusion, producing at the same 

 time those singularly twisted or tangled appearances 

 which so often perplex the geologist in his endeavors to 

 trace them clearly out. Immediately beneath this dis- 



