CHAPTER Vm. 



THE WENONAH SAND. 



The Wenonah formation is usually a black or reddish-brown 

 sand, sometimes strongly micaceous, and often having a peculiar 

 mixture of pinkish, brown, or gray sand grains which give it a 

 characteristic color. Locally it is distinctly laminated, with thin 

 seams of black or chocolate-colored clay. The more ferruginous 

 layers are sometimes cemented intO' a ferruginous sandstone, but 

 cementation oi this sort is less frequent than in the Englisht'own 

 sand. The formation sometimes contains small, amounts of 

 glauconite, but this substance is never conspicuous. T^he upper 

 layers of the formation frequently contain coarse grains of 

 quartz of the size of peas. In Monmouth County the formation 

 is 50 or 55 feet in thickness and is sharply differentiated 

 from both the subjacent and superjacent formations, but towards 

 the south, the Wenonah and the superj acent Mount Laurel 

 sand grow lithologically more ^similar and it is practically 

 impossible tO' distinguish between them from lithologic charac- 

 ters alone, except under extremely favorable circumstances, and 

 consequently it is not possible to make an accurate estimate of its 

 thickness. The thickness of the two sand formations together, 

 however, in Salem County is somewhat over 60 feet, though the 

 Wenonah portion of the bed is probably materially thinner than 

 in Monmouth County. 



FAUNA OF THE WENONAH SAND. 



The fauna of the Wenonah sand has been collected at only two 

 localities, both of which are in Monmouth County. 



At John Longstreet's marl pit, a little less than i mile south- 

 east of Crawfords Corner, and 2>4 miles a little east of north 

 from Holmdel, there is an excellent exposure of the higher beds 

 of the Wenonah sand, with about 25 feet of the superjacent 



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