122 CLAYS AND CLAY INDUSTRY. 



monly pebbly in their basal portion, and not infrequently they 

 are stony throughout. 



Certain of them at levels not exceeding 60 feet, contain marine 

 organisms, and are, therefore, positively of marine origin. They 

 rest directly upon deposits made during the closing stages of 

 the retreat of the glacier from New Jersey, and so may be re- 

 garded as of post-Glacial age, or at most as marking the very- 

 latest stages of Glacial time. Many of -the loams at greater eleva- 

 tions are indistinguishable from these low-level loams, and are 

 apparently continuous with them, so that the post-Glacial or 

 very late Glacial age of the highest loams is probable, although 

 not demonstrable. While it is impossible to> assert that all these 

 loams have had a common origin, yet many facts in the posses- 

 sion of the Survey point to this conclusion, and suggest, even if 

 they do' not prove, the post-Glacial origin of these deposits. In 

 this report, therefore, they will be so considered, although the 

 possibility of other interpretation is not overlooked. 



It is impossible to give in a few words their distribution, 

 since they are so* widespread over the State, and yet so discon- 

 tinuous. They may be looked for at all levels below 200 feet. 

 Thev are extensively used for brick at Trenton and Trenton 

 Junction, and northward to Pennington, where they have been 

 stripped off the surface over many acres, at elevations between 

 100 and 200 feet. At many points, also, between Trenton and 

 Camden, and in the vicinity of the latter place, there is a loam 

 so clayey as to be used for brick. This is the case at The Bor- 

 dentown Brick Company's brickyard (109), Bordentown; S. 

 Graham & Co.'s yard (102), near Fieldsborough ; Murrill 

 Dobbin's yard (113), Kinkora; Joseph Martin's yard (115), 

 Kinkora, and Budd Brothers (143), Camden. At all of these 

 places, however, other clay is mixed with the clay loam. 



Very similar clay loam is also used at Brocklebank's (214), 

 Howell. Monmouth Co., and at Lippincott's (215), near Farm- 

 ingdale. At B. H. Reed & Bros, (193), Hightstown, one of 

 their pits is in a bluish surface clay, somewhat stony, which 

 may be coo-elated in age with these clay loams. At other points, 

 too numerous to mention, the clayey loam occurs, but is not 

 worked. The illustrations in Plate XV show the shallow char- 

 acter of the clay. 



