11(1 Ni:\V VOKK SIAli: .MISKIM 



and similar iiannw icnaccs aic iiol wantinji" farlluM* from the 

 main siicam on IN'cksI^ill and Sjnoui brooks at jiradiinlly in- 

 creasing: liiiiliis altoNc sea \v\v\. 'Vhosr on tlie nortli side of the 

 ((i\c arc Im'si dcvcloj.i d : and of these tiiai forniiiijj^ the state camp 

 is tlic ltioa(hst of all. I am not ahle to say 1h)\v much it has been 

 artificially «!:raded. The sl()j)e of this terrace with its kamelike 

 projections is (niite unlike that of normal river-ciit terraces on 

 the one hand and lobate delta fi-onis on the other; the dej)osit 

 appears to have been built in the presence of ice partially tilling 

 IVekskill creek. The same remark ai)plies to the narrow terrace 

 at the mouth of Annsville creek near the head of the same cove. 



Koa Hook is an outlying rudely conical hill of glacial materials 

 rising to the siime level as the terraces in its vicinity. It has been 

 opened for gravel and sand. On its toj) is a fine yellowish loam, 

 fiom .') to T) feet thick; below this a dark coarse gi'avel bed, 10 to. 

 IT) feel thick, in which one large erratic was exposed in 1900; 

 below which sands occur in the form of foreset beds dipping south- 

 east, making a section about 30 feet thick. Near the railroad 

 track sands occur di])])ing southeast at an angle of 15°. The 

 gravels are locally cemented by carbonate of lime. 



The dark sJialy i)e'bbles in these gi-avels are derived from the 

 j>aleozoic , rocks north of the Highlands in the Hudson valley. 

 This northern source of the materials and the dip of the sand beds 

 to the southe4ist show the direction^ of building of the deposit to 

 have been downstream. The isolation of this deposit is hardly 

 to be explained by the erosion of a once larger and more extended 

 mass of glacial gravels and sands uniting all the terraces about 

 Peekskill creek in a single deposit. The contoui*s of the slopes 

 or blull's of these terraces as well as the untouched slopes of the 

 Jioii Hook mass jireclude that idea ; and the jjostulate of masses of 

 ice ])ai-tly tilling the channel at this ])oint and shrinking away 

 from the lock walls her(^ and 1lHM*e and so ]KM'mitting the build- 

 ing \\\t of deltas and terraces by lateral streams to a nearly 

 (•(Mnni(ni level meets all the rcMiuirements as reg^ards the irregii- 

 laiiiv in oniliiic and dis])osition of the various dejKJsits. 



A notable Icalnre in the deiM)sits of the vicinity of Peekskill 

 is the complete absence of the superficial stratified glacial clays, 

 hr Ivies lias described clays rising about 4 fec^t above high tide 

 level iM-nealh (lie gravel and sand of the 20 foot terrace south of 



