CLAYS OF CRETACEOUS FORMATION. 171 



extent of these deposits, it would not be safe to do more than sug- 

 gest their correlation with this member. 



From the pits at the head of Henry street, South Amboy, the 

 clay bed can be traced along the bluffs by frequent exposures to 

 Perrine's large banks (yy) on Raritan bay. Most of these ex- 

 posures are of the black clay, and the stoneware clay proper does 

 not seem to be present, or, if present, is. thin. Marked variations 

 in thickness and local absence is a feature quite characteristic of 

 the stoneware clay, but nevertheless the fact that it has been 

 opened at many widely separated localities indicates that it was 

 originally deposited over a considerable area. 



Southeast of Perrine's bank, on Raritan bay, the clay descends 

 below sea level, and the overlying sands are exposed along the 

 shore to Morgan station. Since, however, the beds all rise towards 

 the northwest, this clay horizon outcrops along the sides of Cross- 

 way brook valley, where the stream has cut through the clay bed 

 into the sand beneath, except at its headwaters. The approximate 

 line of outcrop is indicated on the map', but the old diggings and 

 borings indicate that the clay is somewhat irregular in distribution 

 and decidedly variable in thickness. It is not at present (1903) 

 being dug along this valley. 



Southwest from Morgan station the clay outcrop follows the 

 sinuosities of the bluff bordering Cheesequake creek. Since the 

 bluff rises steeply, the outcrop is in general a narrow one, even 

 where the clay attains considerable thickness. For the most part, 

 it lies at the foot of the bluff, and underlies the low ground just 

 above the salt meadow. Locally, it extends out under the latter 

 for some distance, but borings have shown that in some places 

 the marsh mud extends down to depths below the level of the clay. 

 This is not to be interpreted as indicating that the clay bed did 

 not formerly extend across the Cheesequake valley to the south- 

 east, but rather that in this direction it was worn away in the 

 erosion of the valley, the bottom of which has since been partially 

 filled with marsh mud. 



As indicated on the map, the Amboy stoneware clay undoubt- 

 edly underlies the high ground west of the bluffs, and connects 

 with the line of outcrops along the Pennsylvania railroad (Cam- 

 den & Amboy Div.). Since, however, the overlying sand and 



