ECONOMIC PRODUCTS AND SUMMARY. 



357 



fertilizers have come into such general favor, the marl industry has 

 waned, to the great disadvantage of the Jersey farmer. Recently some- 

 thing of a revival has taken place, and the local use of the marl seems 

 to be increasing annually. 



Another economic product of some importance is the calcareous de- 

 posit which characterizes the Vincentown lime-sand of the Rancocas 

 formation, and which has been burned for lime at several points in south 

 Jersey. It is largely consumed locally. 



The indurated ferruginous layers of the Matawan and Monmouth for- 

 mations are also used locally for building purposes, in the absence of 

 more suitable materials. The more highly calcareous and ferruginous 

 materials of all the formations are also employed to some extent for road 

 construction, although the superficial Pensauken gravels are better suited 

 and are more extensively used. 



Summary. 



The leading conclusions contained in this paper are as follows : 



1. A marked westerly facing escarpment, called "the Cretaceous escarp- 

 ment," accompanies and characterizes the Upper Cretaceous formations. 



2. The several formations show sufficiently marked differences in the 

 character of their materials throughout the entire distance from northern 

 New Jersey to southern Maryland to readily distinguish them. 



3. The formations, with some local exceptions, thin toward the south 

 and at the same time change considerably in their lithologic characters. 



4. The subdivisions of the different formations, clearly defined at cer- 

 tain points, are unrecognizable at others. In general they grow less dis- 

 tinct toward the south. 



5. The formations are gradually overlapped one after another toward 

 the south, until in the Potomac valley the Tertiary deposits rest directly 

 upon the Lower Cretaceous. 



6. An unconformity is found between the Potomac and Matawan 

 formations, a probable one between the Monmouth and Rancocas forma- 

 tions, and a clearly marked one between the Shark River and later de- 

 posits. 



7. The faunal characteristics of the formations are clearly defined 

 throughout the region, the Matawan-Monmouth faunas being more 

 closely related to one another than the Rancocas-Manasquan-Shark 

 River faunas, while the latter as a whole are sharply defined from the 

 former. 



8. The Matawan-Monmouth faunas, which range through a conform- 

 able group of deposits 400 feet in thickness, are the equivalent of the 



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