224 abstracts: geology 



GEOLOGY.— r/ie geology of Long Island, New York. Myeon L. 

 Fuller. U. S. Geological Survey Professional Paper 82. Pp. 231, 

 with maps, views, and sections. 1914. 



Geologically Long Island belongs to the inner part of the Atlantic 

 Coastal Plain. The line of demarkation between the basal metamorphic 

 rocks and the younger sediments of the coastal plain crosses the extreme 

 western end of the island. There are a few occurrences of Cretaceous 

 clays in the western half of the island, and these make up the basal forma- 

 tion of the sedunentary series. No equivalents of the Tertiary deposits 

 of the mainland have been definitely recognized, although some loose 

 sands possibly of Tertiary age occur at one locality. The greater part of 

 both the surface and the undertying materials throughout the island are 

 Pleistocene morainal and outwash deposits associated with the conti- 

 nental glaciers. Two morainal ridges forming the backbone of the island 

 are the direct continuation of the series of moraines of Wisconsin age 

 that are traceable almost continuously from the Rocky Mountains to 

 New Jersey and thence through Long Island and the islands on the east 

 as far as Nantucket and Cape Cod. Beneath these ridges and above 

 the Cretaceous are various Pleistocene deposits of considerable thick- 

 ness, to be correlated with older drift sheets of the central United States 

 and with the Pleistocene formations of the New England Coast. 



Eight stages have been recognized in the Pleistocene history of Long 

 Island, and some of these are divisible into substages. The oldest, the 

 Manetto stage, which was glacial, is recorded by gravel deposits, and 

 probably of pre-Kansan age. This was followed by Post-Mannetto 

 stage, an interglacial period of erosion and to be provisionally correlated 

 with the Aftonian. A second glacial epoch is represented by the Jameco 

 stage, represented by gravel deposits (Kansan?), and this succeeded by 

 the Gardiner clays, deposited during an interglacial epoch. A tran- 

 sitional epoch to another glacial epoch is recorded in the Jacob sands. 

 The next event is the Manhasset glacial stage, probably to be correlated 

 with the Illinoian. This event is represented by the deposition of a 

 lower gravel member (Herod), succeeded by a second period of ice 

 erosion, then by the deposition of an upper gravel member (Hempstead). 

 Erosion during an interglacial period followed the Manhasset stage, 

 accompanied by the deposition of the Vineyard formation, consisting 

 of marine deposits and peat. In early Wisconsin time glacial condi- 

 tions again prevailed, and this epoch is represented by the older Ronkon- 

 koma or outer moraine and the younger Harbor Hill or inner moraine, 

 both associated with till and outwash deposits. 



