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and gravel, often with plant fragments, into the valleys from 

 the mountains. There were some small lakes, and a few inter- 

 mittent streams existed, but there was apparently no large 

 river in the entire area that is now New Jersey, and the Wat- 

 chung region had no outlet to the sea. 



After the Triassic lava flows had quite ceased, the intrusive 

 diabase masses forming the Palisades and similar southern 

 ridges were pushed up between the hardening sandstones. Dur- 

 ing the Jurassic the whole area was lifted up, probably into low 

 mountains, then subjected to erosion and planed down during 

 the Cretaceous (since late Cretaceous deposits overlay the 

 Tertiary in southern New Jersey). During the Jurassic climatic 

 conditions were changed until they became more as they are 

 today. No fossils are known from the Highlands rocks, but in 

 the Cretaceous beds they are numerous. 



In Tertiary time the Atlantic transgressed over the entire 

 state of New Jersey (and New York up to the Catskill area at 

 least). Fossils from beds of this period represent a wholly 

 marine fauna, with shells and corals much like the modern ones. 

 In the Pleistocene came an uplift of the region and active 

 planing down of the land through erosion of the softer sand- 

 stones and shales, leaving the harder igneous ridges (such as 

 the Watchungs) exposed. This was followed by the southward 

 advance of the glaciers, with their accompanying glacial climate 

 — the ice extending as far south as Staten Island. The terminal 

 moraine runs just east of Plainfield, through the First Watchung 

 at Scotch Plains and through the Second Watchung at Summit, 

 then through the northern extremity of the southernmost ridge 

 of the Third Watchung to Madison and Morristown, just north 

 of the fourth ridge. The retreat of the glaciers left, just north 

 of the fourth ridge and west of the Third Watchung, the old 

 glacial Lake Passaic, of which the lake-bed can still be plainly 

 discerned. We see, thus, that approximately the northern two- 

 thirds of the First, Second, and Third Watchungs were glaciated 

 in the Pleistocene and the southernmost one-third not glaci- 

 ated. The fourth ridge was entirely unglaciated. 



