STATEN ISLAND DRIFT. 93 



of decomposed rock, on the shore near the southwest Hghthouse, 

 filled with fossil remains similar to those of the middle lime- 

 stone of Becroft's Mountain, Columbia county." 



In his final report in 1843, he frequently refers to features of 

 the drift on the island, noting among other facts that the soil is 

 largely colored red by reason of the quantity of red sandstone 

 contained in it. 



In 1 88 1 Dr. N. L. Britton read two papers on the geology 

 of the island, before the Academy, in which the general features 

 of the drift were discussed and the terminal moraine was de- 

 scribed and mapped. (Annals, ii, 161-182; pis. xv, xvi. 

 Transactions, i, 56, 57.) 



During the same year the Natural Science Association of 

 Staten Island was organized, thus providing a medium for the 

 recording of local notes and the preservation of local specimens, 

 and it is largely upon these notes, scattered through its Proceed- 

 ings, and the specimens contained in its museum, that the pres- 

 ent paper is based. 



Location and Extent. 



The terminal moraine extends through the island in an irreg- 

 ular line, from Fort Wadsworth, at the Narrows, to Tottenville, 

 opposite Perth Amboy, N. J. It reaches tide-water at these 

 localities and also near Great Kills, between which point and 

 Prince's Bay it formerly extended beyond what is now the shore 

 line. Only two limited areas are driftless. One of these, about 

 7^ square miles in area, is in the sinus where the moraine 

 bends northward and rests upon the serpentine ridge, in the 

 vicinity of New Dorp ; the other is a similar, smaller area, in the 

 vicinity of Tottenville. 



Structure. 



Where the moraine rests upon the serpentine ridge it presents 

 but few features that are especially striking, consisting entirely of 

 boulder till, gravel and occasional deposits of clay, varying in 

 depth from a mere layer of scattered boulders to accumulations 

 eighty feet in thickness. 



