CORRELATION 387 



for a series of marine sands [and gravels] with occasional minor 

 clayey layers, locally carrying a Pleistocene fauna, which are involved 

 in the folding which affected all the New England islands. The name 

 is from Sankaty head, Nantucket, at which point the fossils were first 

 observed. No true clay was exposed at the type locality except a thin 

 fossiliferous bed only a few feet in thickness, although a series of brownish 

 clayey sands incorrectly designated as clay were exposed to a depth of 

 20 feet at the base of the cliff some 50 years ago.* The remaining por- 

 tions of the bluff were made up mainly of sands, gravels, and semi-till. 



Later Mr A. C. Veatch applied the same name f on the basis of its 

 similar fauna to the blue, gray, or red Pleistocene clays of Long and 

 Gardiner islands, in the former of which they reach, according to the 

 evidence of wells, a maximum thickness of about 100 feet. The writer 

 was originally inclined to the use of this term, J but subsequent field 

 work, during which the shores of the greater part of Long, Gardiner, 

 Plum, Fishers, and Block islands were traversed and the bluff sections 

 of Marthas Vineyard, Nantucket, and cape Cod visited, brought out the 

 fact that the true clays in each of the localities mentioned are strati- 

 graphically below the lowest of the deposits at Sankaty head, and hence 

 should not be included in the term. Moreover, the Sankaty beds of 

 Woodworth are separable into two distinct formations, the Jacob sands 

 and the Herod gravels (see pages 378 and 381), each of which has been 

 traced by the writer from western Long island to Nantucket. 



The true clays, to which the term " Gardiner " is given, and the Jacob 

 sands are interglacial deposits, while the Herod gravels are in part, at 

 least, of glacial origin. The term " Sankaty," as used by Woodworth, 

 therefore, includes materials not only of unlike character, but also of 

 diverse origin, while as used by Veatch it includes only a part of the 

 interglacial series. If the term is to be retained, as it possibly will be 

 (because of the well known fauna of Sankaty head), it should, in the 

 writer's opinion, be limited to a single class of deposits, namely, the 

 interglacial deposits here separately described under the headings of 

 Gardiner clay and Jacob sands. The glacially derived Herod gravels 

 should be excluded. 



CORRELATION WITH THE DRIFTS OF PENNSYLAANIA, MISSISSIPPI VALLEY, 



AND CANADA 



The geologic successions on Fishers island seem to be essentially sim- 

 ilar to those existing on Long island, which may be considered as the 



* E. Desor and E. C. Cabot : On the Tertiary and more recent deposits in the island of Nantucket. 

 Geol. Soc. Quart. Jour., vol. v, 1849, pp. 340-344. 

 fThe diversity of the glacial period on Long island. Jour, of Geol., vol. xi, 1903, pp. 762-776. 

 X Probable pre-Kansan and Iowan deposits of Long island, New York. Am. Geol., vol. 32, p. 311. 



