CLAY DEPOSITS IN OLDER SYSTEMS. 207 



Warren and Sussex counties in Kittatinny mountain and the 

 lower country on the west, and also in the Green Pond-Bearfort 

 mountain region. The shales are nowhere utilized, and no tests 

 have been made of them in this investigation. They are for the 

 most part sandy and unpromising. 



CAMBRIAN AND ORDOVICIAN. 



The Cambrian and Ordovician rocks are limestones and shales 

 with some beds of sandstone and quartzite. They occur chiefly in 

 Warren and Sussex counties in the great Kittatinny valley, be- 

 tween the Kittatinny mountain on the northwest and the High- 

 lands on the southeast. They also- occur within the Highland area 

 in the valleys of the Musconetcong and Pohatcong, the South 

 Branch of the Raritan northeast of Calif on, and in the Green Pond 

 mountain region. They also are found in a few small areas south- 

 east of the Highlands between the crystallines and the Trias red 

 shale, the largest of these isolated areas being in the vicinity of 

 Clinton and Pattenburg. 



Southwest of the terminal moraine, which marks the south- 

 ward border of the region covered by the ice of the last Glacial 

 epoch, the rocks are in places somewhat deeply weathered and 

 buried beneath the products of their own disintegration. The 

 limestone commonly weathers into a yellow sticky clay, containing 

 more or less abundantly the insoluble black cherts or flints, which 

 occur in it. Locally beds of clay may thus be formed, partly 

 by the decay of the rock beneath and partly by the wash from 

 similar material on higher slopes. The smooth clay on the prop- 

 erty of L. T. Labar, near Beattystown (Loc. 283), has probably 

 originated in this way, 1 although some of it may belong to a 

 very early glacial drift. 



At Alpha (Loc. 278), near Phillipsburg, the Portland cement 

 rock (Trenton age) is covered by 3 or 4 feet of yellow sticky 

 clay, with a soapy feeling, which contains occasional small masses 

 of vein quartz, etc., and which was derived from the cement rock 



1 See Chapter XIX for physical tests of these clays. 



