78 Geology of Hudson Cotmty, Xeio Jersey. 



Note iy the Editor. 



[It is regretted, that owing to the large amount of space required, it has 

 proved impossible to give the detailed sections, carefully prepared by the 

 author of this paper, from official records of the several pier-borings on 

 the East and North Rivers. In the case of the latter, it will be seen from 

 the Table that the "lower deposits" lying between the "dock mud" and 

 the bed-rock, and reaching in some cases a thickness of 100 feet, disappear 

 almost wholly in the short distance westward to the ends of the piers. 

 Where these end-borings are recorded, the mud, with a few slight ex- 

 ceptions, rests directly upon the rock-bottom ; while the miscellaneous 

 succession of sand, clay, gravel, boulders, shells, vegetable matter, etc., 

 found under the piers on both rivers, nearer to the shore, is wanting. 



In the case of the piers above 23d Street, it was not practicable to judge 

 clearly of the line of demarcation between the modern mud and the older 

 deposits below, so that these columns are left blank. 



Attention may be called, also, to the transverse valleys indicated by 

 the increasing depth of the bed-rock on both sides of the city (in passing 

 northward from the Battery, culminating at pier 24 E. R. , and the foot of 

 60th Street, N. R. The pre glacial rock-surface of Manhattan Island needs 

 fuller and further illustration for its proper determination, and all facts of 

 this kind should be carefully recorded and preserved. J 



MINERALS OF THE TRAP. 



The following is a list of the mineral species and varieties discovered up 

 to the present time at Bergen Hill. 



Zeolites. Thomsonite, Natrolite,* Analcite,* Chabazite,f Gmelinite,f 

 Stilbite,* Sph8erostilbite,f Heulandite.f 



Other Silicates. Apophyllite,* Prehnite,* Laumontite,* Pectolite,* 

 Datolite ;*Orthoclase, Hornblende, Byssolite.f Augite; Prochlorite; Sphene.f 



Other Species. Calcite,* Siderite;f Quartz,f Hyalite ;f Pyrite, Chalco- 

 pyrite.f Blende,f Galenite.f 



Besides these may be mentioned some species that are but imperfectly 

 determined as yet; among these are the chloritic mineral that has been 

 called Diabantite, and the "Brown pectolite," which appears to be a mag- 

 nesian alteration of pectolite. 



Those species followed by a * are abundant and yield choice specimens : 

 those marked with a f are found but rarely and in small quantities. 



MINERALS OF THE SERPENTINE. 



The serpentine ridge of Hoboken has long been celebrated as a locality 

 for magnesian minerals. The following species are thence obtained. 



i 



