G('(tlo(jfi of Jiirhiiwn<l (Jounhi, X. ¥. 177 



(2) Ore from near Four Corners — 



(A) Fe, 0, 

 Al.. 0, 



79.2; 

 1.20 



(B) 



76.72 

 0.96 



Cr', 0, 



1.1.-) 





1.60 



Mii., 0, 



0.32 





0.64 



«i 6., 



5.70 





.5.52 



Ca 



tr. 





tr. 



Mg- 

 H., () 



tr. 

 12.39 





tr. 



14.76 



P' 



tr. 





tr. 



,s 



tr. 











100.03 100.20 



Metallie iron in (A), 55.49 pr. et. 

 •' (B). 53.70 •• 



These superticial deposits liave probably bad their origin in 

 the deposition of the material composing them from the waters 

 of thermal springs, which have come to the snrface through 

 crevices in the serpentine ; the iron in the solutions was proba- 

 bly in the form of the carbonate, which on reaching the surface 

 became oxidized by contact with the atmosphere, and Avas 

 thrown out of solution and deposited as the hydrated sesqui- 

 oxide, as we now find it. Magnetic iron sand occurs with the 

 Limonite in one of the deposits on Todt Hill; this was proba- 

 bly washed in mechanically while the hydrated oxide was being 

 deposited from solution. 



The deposits vary from a few inches up to twelve feet, or even 

 more, in thickness : their lateral extent is limited to a few hun- 

 dred feet in any direction. The Todt Hill mines are the only 

 ones wholly uncovered by glacial drift, being east of the mo-, 

 raine. 



^Eolian or Blown Sand. — Extensive deposits of light-colored 

 sand, similar in character to those found so abundantly on Ber- 

 gen ISeck, N. J., occur along the edges of the salt meadows on 

 the western side of the Island, from Mariners' Harbor to near 

 Chelsea Landing, sometimes extending to a distance of one-half 



