^28 TRANSACTIONS OF THE [aPKIL 19, 



MINERALS OF STATEN ISLAND. 



The lovely island that graces New York harbor is at present 

 nssuming new importance, by reason of its connection with con- 

 templated railway enter]irises affecting the interest of the metrop- 

 olis, and it is not improbable that, as this hitherto quiet region 

 awakes from its long repose at the magic touch of commei-cial 

 enterprise, new opportunities may be afforded for scientific 

 research. 



Our English friends have given it the title of the "Isle of 

 ^^igllt of America." It is thought that certain features of 

 scenery justify the comparison. 



Tlie geological student may be permitted to suggest additional 

 parallelisms. 



Both islancls are of an irregular rhomboidal form, each sepa- 

 rated from the nniinland by narrow channels. Eacli j^resents 

 elevated contours of considerable height. The range of downs 

 traversing the English isle finds a resemblance of featui-e in 

 the gently rounded glacial-drift hills of Staten Island. Mighty 

 geological changes have cluiracterized the history of both islands, 

 and succeeding epochs, with comparatively quiet conditions, 

 have left in each tiieir record of marine deposits. 



Sir William Jardine recommended Britisli students in geology 

 to make the Isle of Wigiit a special field of investigation. Amer- 

 ican students, especially those of the metropolis, may find it sim- 

 ilarly profitable to make oui- neighboring island worthy of their 

 attention. 



Tlie starting-point for an exi)loration of the island miglit, with 

 proin-icty, be the bit of azoic rock outcropjiing near the Tomjv 

 kinsville landing. Here the collector may carry away as metnen- 

 toes of the locality fragments of })ota8h felJspar of the typical 

 structure and color, gray quai'tz, and, i)erhaps, fair specimens 

 of muscovite, these constituting an aggregate of coarse granite. 

 Tlie traveller who, at some future day, nuiy take a through train 

 to Baltimore from near this ))oint, will see no further outcrop- 

 pings of the azoic formation until he reaches the Delaware 

 River. 



The hills in front of ns, as we look up from the shores of the 

 Narrows, are chiefly serpentine and steatite, which, according to 

 recent investigatoi-s, have their origin by metamorphism from 

 the hornblendic schists of the primitive formation. Innumei-able 

 broken fragments in our ])ath are of an angular foi'm and of a 

 great variety of tints, in which light-green predominates. It is 

 somewhat unlike the serpentine at Iloboken, and varies very 

 materially from that on New York Island. 



