1/2 THE JOURNAL OF GEOLOGY. 



altogether satisfactorily explained, although the deposits indicate 

 that they were largely derived from crystalline rocks. 



That the red sandstones and shales of the Jura-Trias (Newark 

 Formation) which adjoin the coastal series upon the landward 

 side have not been the source of the materials is a striking fact, 

 and one which has been largely commented on in the past. By 

 some it has been supposed that an area of crystallines must have 

 existed to the eastward to afford the materials for the deposits 

 under consideration. A study of the drainage of the Jura-Trias 

 belt which separates the coastal formations from the area of crys- 

 talline rocks beyond, is of interest, however, in showing the prob- 

 able extension of the coastal deposits quite over the red sand- 

 stones and shales of the Jura-Trias to the border of the crystal- 

 line region and at the same time affords a sufficient explanation 

 for the absence of sediments derived from the Jura-Trias itself. 

 The evidence for this has been recently presented by Davis ^ in 

 the National Geological Magazine, and the reader is referred to 

 the article for a fuller explanation of the subject. 



Accepting the explanation of Davis as highly probable we 

 may look for the source of the land-derived materials out of 

 which*the greensand deposits are formed, in northwestern New 

 Jersey, eastern Pennsylvania and southeastern New York, in a por- 

 tion of that tract of crystalline rocks which stretches along the 

 eastern side of the continent. A separation of the mineral con- 

 stituents of the greensand deposits shows a preponderance of 

 both the constituent and accessory minerals which characterize 

 those rocks. It seems conclusive, therefore, that the area men- 

 tioned was the source of the materials for the greensand deposits 

 of eastern New Jersey. 



TAXONOMY. 



The geological formations of New Jersey early attracted the 

 attention of geologists, and Professor Peter Kalm^ of Sweden, 



' Nat. Geog. Mag., Vol. II., No. 2, pp. 1-30, 1890. 



^EnResatil Norra America 8vo. 3 vols. 1753-61, Stockholm. Translations in 

 English by J. R. Forster ist. Ed. 1770-71, 2nd. Ed. 1772, another Ed. in J. Pinkerton's 

 Voyages, Vol. 13, 1812; in German by J. H. Murray, 1754-64; in French by L. W. 

 Marchand, 1859. 



