56 FOURTH REPORT — 1834. 



the age of the gvair.vacke and carboniferous formations, in as 

 much as the two have been seen by Mr. Conrad in the northern 

 part of that State ahnost in contact. 



The whole of the above-described strata of North Jersey 

 might seem to merit the name of the greensand formation of 

 the United States, and I should propose applying this designa- 

 tion to the deposit, in lieu of that of ferruginous sand, w^hich 

 A\ as originallj^ appropriated to it by Dr. Morton, were it not, 

 first, that the greensand being but little developed jmiong the 

 beds of the same periods in the vast formations of the south, 

 the name would not be expressive of the prevailing character of 

 the group, except in the comparatively very limited area of 

 New Jersey ; ami secondly, that in the present early stage of 

 our discoveries, I am not entirely satisfied as to what are its 

 true relations to the European formations, and therefore hesitate 

 to appropriate to it the title of a formation with which there is 

 little prospect of its ever being shown to be strictly identical 

 either in mineral structure or organic contents. 



The following more detailed description of these formations 

 in New Jersey is so well and succinctly given by Dr. Morton 

 in the recent edition of his Si/nojisis, that I shall extract the 

 accour.t almost entire. 



" Ferruginous Seoul. — In New Jersey the tract which has 

 been known by the name of the marl district may be located as 

 follows : Draw two lines, one fi'om Amboy to Trenton, the 

 other from Deal to Salem ; let the Atlantic Ocean connect the 

 eastern, and the Delaware river the western points of these 

 lines : this irregular oblong tract incloses nearly the whole 

 marl deposits of New Jersey, so far, at least, as it has hitherto 

 been explored. There is reason, however, to suppose that it 

 occupies a much larger proportion of the peninsula, especially 

 in some places, overlaid by deep deposits of clay and sand, as 

 at Bordentown, White Hill, &c. 



'■ In other localities, the older pleiocene (uiciocene) overlies the 

 sccrndary, as is the case a few miles from Salem. 



'• The fossils, as will hereafter be shown, are of a very strik- 

 ing character, occasionally grouped in vast numliers, and in 

 other instances almost wholly absent. The genera Gri/p/iceOy 

 I''!.vogi/ra, and Belemnites are found abimdantly thi'ougbout." 



" Calcareous Strata. — The calcareous beds have been traced 

 as far south as Salem, and north to Vincent town, a tract of 

 nearly sixtj^ miles in length, in a direction nearlj?^ parallel to the 

 Delaware river, and from seven to ten miles east of it. They 

 are marked throughout by the several varieties of calcareous 

 VtH'k already described, and characterized by abundance of zo- 



